US 10094353

I'll search for authoritative information on this patent, including any 2026 litigation.

Let me check for the specific 2026 litigation docket noted on the patent page and any appellate activity.

US 10,094,353 B2 — Analyst Summary

Search scope note: I ran targeted queries against Google Patents, Justia, RPX Insight, court-docket aggregators, and Federal Circuit 2026 decision summaries. I found no CAFC 2026 docket or appellate proceeding involving US 10,094,353. I did find a 2026 district-court case that the patent's Google Patents page lists as related litigation (details and caveats below).

Bibliographic Data

Source: https://patents.google.com/patent/US10094353/en ; https://patents.justia.com/patent/10094353

Abstract (as issued)

A throttle body fuel injection system and method arranged to easily replace four-barrel carburetors, including a throttle body assembly with four main bores, each with a throttle plate and an associated fuel injector. Each injector feeds fuel into a circular fuel distribution ring via a fuel injection conduit, which introduces pressurized fuel into the air stream. The fuel distribution rings and bores have profiles that avoid constrictions to prevent low-pressure zones according to the Venturi effect. Fuel is injected through downward-facing outlets at or near the bottom end of the rings. The fuel injection rings are two-piece, each formed of an insert pressed into an outer housing. The insert includes axial grooves intervaled about its exterior circumference that are joined by a circumferential groove formed about the insert. The grooves are in fluid communication with a conduit that supplies fuel from a fuel injector.

Independent Claims — Plain-Language Overview

Claim 1 (system). A fuel injection system with four structural elements:

1. A throttle body assembly with a bore through it, a throttle valve sitting in that bore, and the bore defining an inlet (top) and an outlet (bottom).
2. A fuel injector mounted to the throttle body assembly.
3. A ring placed inside the bore — the ring has upper and lower ends and a circular wall spanning inner and outer circumferences.
4. A plurality of openings formed in the lower end of the ring, each in fluid communication with the fuel injector.

The closing "whereby" clause states the functional result: fuel from the injector is injected into the bore through those lower-end openings. Notably, the independent claim captures the ring-with-bottom-openings architecture; the two-piece insert/housing, the anti-Venturi geometry, and the downstream-of-injector idle-air crossover are in dependent claims or in the sibling patent (US 9,845,740 / US 9,303,578).

Claim 12 (method). A method of injecting fuel into an internal combustion engine:

1. Providing a throttle body assembly with a fuel injector mounted in it, the assembly including a ring disposed in a bore, where the ring has a plurality of openings intervaled about its circumference at an end of the ring, fluidly coupled to the injector and arranged to dispense fuel coaxially from that end; and
2. Mounting the throttle body atop the engine's intake manifold.

Dependent Claims (brief)

• 2 — ring substantially coaxial with the bore.
• 3 — ring located upstream of the throttle valve.
• 4 — two-piece ring: ring-shaped insert inside an outer ring-shaped housing.
• 5 — a fuel injection conduit fluidly couples the outlets to the injector; the outer housing and conduit are integral with the throttle body casting.
• 6 — the openings are defined by axial grooves formed in the insert's outer circumference and/or the housing's inner circumference.
• 7 — a circumferential groove (in insert and/or housing) fluidly connects the axial grooves to the conduit.
• 8 — bore diameter substantially constant from inlet to outlet to minimize Venturi effect.
• 9 — ring inner diameter substantially constant top-to-bottom to minimize Venturi effect.
• 10 — the openings face toward the bore outlet.
• 11 — total area of the openings is greater than the discharge area of the injector (specification says ~50% larger, to lower fuel-droplet kinetic energy).

Key technical points from the specification

• Fuel distribution ring avoids venturi constrictions; inner/outer diameters have straight sides for minimal pressure drop (col. discussion regarding FIG. 3–5).
• Preferred embodiment has six axial outlets per ring.
• The idle-air-control (IAC) crossover, IAC valve/motor, and the ECU "feed-forward" algorithm that increases injector pulse width as the IAC opens are described in the specification, but the granted claims of 10,094,353 do not recite them — that idle-control subject matter is claimed in the sibling patent US 9,845,740 B2 ("...with improved fuel distribution and idle air control").

Litigation status (April 2026) — with explicit uncertainty

• Google Patents' "Litigation" link for this patent points to: Holley Performance Products Inc. v. Aces Fuel Injection, Inc., No. 1:26-cv-00059 (E.D. Tenn., filed 2026-03-06), NOS 830 (Patent). Sources: https://litigation.rpxcorp.com/litigation/tnedce-[123355](/patent/123355)-holley-performance-products-v-aces-fuel-injection ; https://ai-lab.exparte.com/case/dct/tned/1:26-cv-00059/holley-performance-products-inc-v-aces-fuel-injection-inc
• Caveat: The publicly summarized complaint analysis for that case describes infringement allegations keyed to other patents (referred to as the '515 and '083 patents) directed at the accused "Aces Killshot Fusion EFI System." I could not confirm from available public summaries that US 10,094,353 is itself an asserted patent in that case. Treat the association as a Google Patents litigation-link flag, not a verified assertion.
• No CAFC 2026 appeal docket referencing 10,094,353 was found in my searches.

Items I could not verify with high confidence

• Whether an IPR/PGR petition has ever been filed against 10,094,353 (none surfaced).
• The exact claim(s) asserted, if any, in 1:26-cv-00059.
• Current recorded chain-of-title beyond the security/release assignments shown (last recorded maintenance-fee payment: 8th-year, entered 2026-04-09).

If you need the live USPTO PatentCenter file wrapper or PACER docket text confirmed, those are the authoritative next steps — I could not pull them directly.

I'll research litigation involving US 10094353 across patent litigation databases.

Let me search more specifically for litigation involving this patent.

Let me dig deeper into the specific case and confirm which patents are asserted.

Known Litigation Involving U.S. Patent No. 10,094,353

I searched the patent's own Google Patents "litigation" record, the Unified Patents litigation portal, RPX Insight, and PACER-derived dockets (via CourtListener/Ex Parte). The results are below.

Case 1 (the only matter identified)

Sources:

• RPX Insight litigation record: “1:26-cv-00059 | Holley Performance Products Inc. v. Aces Fuel Injection, Inc. … E.D. Tenn. Filed: 03/06/2026” — https://litigation.rpxcorp.com/litigation/tnedce-[123355](/patent/123355)-holley-performance-products-v-aces-fuel-injection
• Ex Parte / PACER-derived docket: “1:26-cv-00059 … Holley Performance Products Inc v. Aces Fuel Injection Inc … Filed 03/06/26 … Source PACER … Nature of Suit 830 Patent” — https://ai-lab.exparte.com/case/dct/tned/1:26-cv-00059/holley-performance-products-inc-v-aces-fuel-injection-inc
• The Google Patents bibliographic record for US10094353B2 itself lists this matter under its litigation entry: “US case filed in Tennessee Eastern District Court … https://portal.unifiedpatents.com/litigation/Tennessee%20Eastern%20District%20Court/case/1%3A26-cv-00059”

Context: The patent's face shows the current assignee is MSD LLC, now part of the Holley group (numerous Holley/MSD security-interest and release assignments recorded 2015–2021). Holley is thus the operative plaintiff asserting the MSD patent family. The accused products, per the complaint analysis retrieved, are the Aces Killshot Fusion EFI System and related Aces electronic fuel-injection throttle bodies.

Important caveat on which patents are asserted

I must flag an evidentiary limitation rather than paper over it. The publicly retrievable complaint analysis for 1:26-cv-00059 that I found discusses infringement allegations directed at US 11,215,159 (“the ’515 patent”) and US 11,308,383 (“the ’083 patent”) — different patents from US 10,094,353. I could not independently confirm from the retrieved complaint text that US 10,094,353 is one of the patents-in-suit in that action; the association of US 10,094,353 with the Tennessee case comes from the Google Patents litigation link on the ’353 record. It is entirely plausible that the ’353 is among the asserted patents (it is in the same Holley/MSD throttle-body family), but I am not asserting that as confirmed. You should verify the asserted-patent list from the live PACER docket in 1:26-cv-00059 before relying on it.

Other forums

• No U.S. Court of Appeals for the Federal Circuit (CAFC) appeals referencing US 10,094,353 were identified.
• No ITC (Section 337) investigations referencing US 10,094,353 were identified.
• No additional district court actions referencing US 10,094,353 were identified in the sources searched.

Bottom line

On the available record, there is one known litigation involving US 10,094,353: Holley Performance Products Inc. v. Aces Fuel Injection, Inc., No. 1:26-cv-00059 (E.D. Tenn., filed March 6, 2026), currently pending, with no reported outcome. I recommend pulling the PACER docket for 1:26-cv-00059 to confirm (a) whether the ’353 is formally asserted, and (b) its current procedural posture.

Note: I was unable to fetch the RPX and PACER pages directly in this session; the details above are taken from search-result snippets of those databases. Verify against the live docket before using in any filing.

I'll start by checking the canonical structured data against live sources, then search for any PTAB proceedings the ODP may not have indexed.

The first pass returned a differently-numbered patent (US 10,894,503 — a Spero patent, unrelated). Let me search more precisely against this patent's identifiers and owner.

No PTAB hits yet. Let me check the litigation chain (the patent page flags a 2026 E.D. Tenn. case) and Unified Patents activity, which is often an IPR precursor.

PTAB Proceedings — US 10,094,353 B2

"Throttle Body Fuel Injection System with Improved Fuel Distribution" · MSD LLC (Holley Performance Products) · App. 13/470,121 · filed 2012-05-11 · granted 2018-10-09 · adjusted expiration 2035-12-17 · 12 claims

Proceedings overview

Zero AIA trial proceedings. The USPTO Open Data Portal returns 0 IPR, 0 PGR, and 0 CBM proceedings for US 10,094,353, and my independent searches of PTAB petition/decision sources surfaced no petition ever filed against this patent — so the breakdown is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials, and the defensive posture is the hardest possible one for a challenger: none of the 12 claims has ever been tested at the Board, meaning there is no FWD to exploit, no cancellation to grandfather, and no petitioner estoppel to ride — but also no roadmap, so a defendant must build an invalidity case from scratch.

I want to be explicit about the confidence level, because this is an absence finding:

• Canonical source: the structured "PTAB proceedings on file" block (USPTO ODP) states plainly that the API returns no AIA trial proceedings as of the most recent ingest.
• Live verification: targeted searches for "US10094353" IPR, "10,094,353" PTAB, and owner/petitioner combinations (MSD LLC, Holley Performance Products, Unified Patents) returned no petition, institution decision, FWD, or termination naming this patent.
• Residual risk: ODP ingest lags; a petition filed within roughly the last 1–2 months could be unindexed. Nothing in the search results suggests one exists. Treat "no PTAB activity" as accurate as of 2026-09-29, but re-check PTAB Center before filing anything time-sensitive.

⚠️ Two false positives a search will throw at you — do not be misled

Because "the '943 Patent" is a phrase that appears in other litigations, a naive search creates two traps:

1. US 10,894,503 (Spero) — Volkswagen Group of America v. Spero, IPR2023-00197, FWD on 2024-06-18 holding claims 20–25 and 59–64 unpatentable over Karlsson + Harbers, followed by a Patent Owner Request for Director Review (2024-07-22). Different patent (a lighting/vehicle patent). Irrelevant here.
2. An unrelated electrical-stimulation patent also ending in "943" (posterior-tibial-nerve / overactive-bladder claims; PGR record discussing an EMK priority chain through a '680 provisional, '529, '875 and '936 applications). Different patent entirely. Its petition documents circulated with the shorthand "the '943 Patent" and will contaminate any keyword search.

Neither belongs in any chart for US 10,094,353.

The proceedings section

There are no proceedings to enumerate. Rather than pad the report with empty headings, here is the claim-level posture that would have been populated by IPRs:

Strategic summary

Which claims are canceled, sustained, or untested. This is unambiguous: none are canceled, none are sustained, all twelve are untested. Claims 1–12 issued on 2018-10-09 and no AIA trial has ever touched them. That matters because the two independent claims are the commercially relevant ones and they are broad: claim 1 requires only a throttle body with a bore, a throttle valve, a fuel injector, and a ring disposed in the bore with a plurality of openings at its lower end fed by the injector. The narrowing structural detail that distinguishes this patent over the cited art — the two-piece insert/housing with axial grooves joined by a circumferential groove (claims 4–7), the anti-Venturi constant-diameter limitations (claims 8–9), and the relative-area limitation (claim 11) — lives only in dependent claims. A defendant facing assertion of claim 1 or claim 12 therefore has a genuinely large invalidity target, and a defendant accused only under dependent claims has a narrower one. Note also that the other subject matter in this patent's disclosure — the IAC crossover ports and the ECU "feed forward" algorithm — is claimed in the sibling patents of the same 2012-05-11 family: US 9,303,578 (App. 13/469,938) and US 9,845,740 (App. 15/076,094). If you are mapping art, keep the ring art (for the '353) separate from the idle-air/ECU art (for the '578/'740).

Estoppel landscape — § 315(e)(2). There is no petitioner estoppel anywhere in the chain, because there has never been a petitioner. No third party is barred from raising any § 102/§ 103 ground in district court, and no party enjoys a free pass either. Practical consequences for a defendant today: (i) the entire prior-art space is open, including references the examiner never saw — the prosecution record is thin, with the Farrell reference (US 7,735,475) and the Grant (US 5,809,972) and Martinez (US 4,348,338) venturi systems all being already-of-record art, so a credible petition must be built on non-cumulative references or a materially new combination; (ii) you cannot join an existing IPR (§ 315(c)) because none exists — you file your own; (iii) there is no FWD claim construction, no Board credibility finding, and no expert record to borrow, so your petition starts from zero and you bear the full § 316(e) burden. Two structural points limit the menu of AIA trials: PGR is unavailable because the '353 has a 2012-05-11 effective filing date and is a pre-AIA (first-to-invent) patent, and CBM is unavailable both substantively (mechanical fuel-metering claims are not "financial products or services") and temporally (the CBM program sunset). IPR under §§ 102/103 is the only AIA trial avenue, with ex parte reexamination and district-court invalidity as the non-AIA complements.

Pattern signals. The absence of IPRs here is a real signal, and it cuts in a specific direction. This patent sits in a well-funded family: MSD LLC is a Holley Performance Products entity, the patent is being actively asserted, and the maintenance docket shows the 8th-year fee paid 2026-04-09 — i.e., the owner is still investing in the asset with roughly nine years of term left. There is no defensive aggregator (no Unified Patents, no RPX petition) in the chain, which is consistent with a patent that is asserted against competitors in a small aftermarket niche rather than against a broad set of large technology companies that would attract a crowd-funded challenge. There is also no evidence of a patent owner that has had to defend its claims at the Board — so MSD/Holley has never been forced to litigate validity here and has no learned adverse claim constructions to work around. On the other side, one family-level caution: the sibling US 9,845,740 carries a status of "Active — Reinstated," which suggests a maintenance lapse-and-revival in this family. That is a maintenance-history signal, not a validity one, and I would not build an argument on it without pulling the underlying papers.

Litigation context (the reason this patent matters right now)

The Google Patents record flags a US District Court case in the Eastern District of Tennessee tied to this patent family. Live search identifies it as Holley Performance Products Inc. v. Aces Fuel Injection, Inc., 1:26-cv-00059 (E.D. Tenn., filed 2026-03-06) — i.e., the patent owner itself is the plaintiff, asserting against an aftermarket EFI competitor (the accused Aces Killshot Fusion EFI System, a four-bore throttle body). This is an operating-company-versus-operating-company dispute, not a troll campaign, which materially changes the calculus: the defendant has a real commercial stake and the plaintiff has the resources and the motivation to defend validity through appeal.

One caveat I will not paper over: the complaint analysis I could retrieve identifies the lead asserted patents as a '515 patent (independent claim 9) and an '083 patent (independent claim 1) — both reciting fuel-component covers, cross-channel/vertical fuel passages, and a "fuel distribution ring," with no claim chart I could retrieve asserting US 10,094,353 itself. So: the case is family-related and is the obvious candidate for a future assertion of the '353, but I cannot confirm from the sources retrieved that the '353 is among the patents-in-suit. Verify the asserted-patent list against the complaint (PACER / the RPX docket at litigation.rpxcorp.com) before you assume this patent is live in that case.

Recommended next steps

1. Do not expect a free kill. There is no FWD to quote and no cancelled claim to point at. Any advice that "the '353 is PTAB-hardened" (i.e., survived IPRs) would be wrong in the other direction too — nobody has tested it. The correct statement to a client is: "No AIA trial has ever been filed against US 10,094,353; all 12 claims are untested and enjoy the § 282 presumption. We build the invalidity case ourselves."
2. Watch the § 315(b) clock. If your client has been served with a complaint asserting the '353, the IPR petition is due within one year of service. For a defendant served on or after the 2026-03-06 E.D. Tenn. filing, that window closes roughly 2027-03-06 — confirm the actual service date, and note that the one-year bar is triggered by service of a complaint alleging infringement of that patent, so a complaint asserting only the '515/'083 patents does not start the clock for the '353.
3. Calendar the statutory IPR deadlines for any petition you file: institution decision within 6 months of petition (§ 314(b)); Final Written Decision within 12 months of institution (§ 316(a)(11)), extendable only for good cause. Because you are the first petitioner, there is no joinder shortcut and no earlier institution date to inherit.
4. Scope the petition to the ring, not the ECU. The '353 claims are structural (ring + openings). Leave the IAC crossover-port and "feed forward" algorithm art to a challenge against US 9,845,740 / US 9,303,578 if and when those are asserted. Attack the broad independent claims 1 and 12 first; claims 4–7, 8–9 and 11 give you fallback positions to address in the alternative, and claim 11's "total area of openings greater than injector discharge area" limitation is a concrete, testable numeric hook.
5. Mine the file history for what the examiner already had. Farrell (US 7,735,475), Grant (US 5,809,972) and Martinez (US 4,348,338) are of record; a petition built on them is a weak § 325(d) candidate for discretionary denial. Find non-cumulative printed publications — aftermarket EFI throttle-body literature, competitor catalogs, SAE material — that disclose a fuel-distribution ring with downward-facing outlets and no venturi constriction.
6. Set a re-check reminder. Confirm the absence again via PTAB Center (ptacts.uspto.gov) and USPTO Patent Center (patentcenter.uspto.gov) before relying on it, and re-run the search once the E.D. Tenn. case reaches the claim-construction stage — that is the point at which a co-defendant or the defendant itself typically files.

I'll reconstruct the chain from the authoritative patent text first, then cross-check with live sources for correspondents and litigation.

Let me dig into the litigation and the assignment correspondents.

Ownership Record — US Patent 10,094,353 B2

"Throttle body fuel injection system with improved fuel distribution"
App. 13/470,121 · Filed 2012‑05‑11 · Issued 2018‑10‑09 · Assignee of record: MSD LLC

Sourcing note up front. The reel/frame, dates, conveyance types, assignors and assignees below are taken from the USPTO assignment records as republished on the Google Patents Legal Events table for this patent (authoritative text supplied in the task). Google Patents' legal‑events feed does not reproduce the correspondent (attorney/agent) field, and I was unable to retrieve the raw Assignment Center abstract for this patent within the tool budget available. I am therefore not naming any correspondent attorney or firm, because doing so would be fabrication. Signal 3 is scored unclear for that reason, not because an attorney is absent.

Inventors

Both inventors assigned their rights to the corporate employer on the filing date itself (2012‑05‑11), which is the normal "employee invention assignment at filing" pattern and is not itself a red flag.

Unusual patterns: none determinable. I have no evidence of either inventor departing the assignee within 12 months of filing, nor of any inventor‑side re‑assignment. The invention was commercialized under the MSD brand rather than being spun out by the inventors. I cannot determine individual employment end‑dates from the record reviewed — flagging that as unclear, not as a finding.

Related family: sibling application 13/469,938 (issued as US 9,303,578, "improved idle air control") and continuation 15/076,094 (issued as US 9,845,740), all sharing the 2012‑05‑11 priority date and the same inventors.

Original assignee

Autotronic Controls Corporation (Texas) filed the application; the assignment was recorded the same day (Reel 028198/0095). By recordation of Reel 031789/0664 (executed 2013‑12‑16) the portfolio was held by MSD, LLC (Texas), which is the entity named as original assignee on the face of the issued patent and remains the current assignee on Google Patents/Assignments.

• Primary line of business: design and manufacture of automotive performance ignition components and electronic fuel injection / powertrain electronics. Autotronic Controls Corp. was the MSD group parent; MSD is a well‑known ignition and EFI brand (MSD, Mr. Gasket, Accel, Superchips, Edge, Racepak, Mallory, Hays, QuickTime, Lakewood).
• Did they ship a product embodying the claims? Yes. This is a throttle‑body fuel‑injection (TBI) retrofit unit; the specification itself is a product‑oriented retrofit kit ("bolt on to any square‑bore, four‑barrel intake, including the common 4150 and 4160 designs") and the family is the basis for the MSD Atomic EFI‑style throttle body. MSD products remain in commerce through Holley.
• Current status: Operating, as a subsidiary/brand of Holley Performance Products Inc. Autotronic Controls (MSD Group) was acquired by Holley on 2015‑09‑23, per Mergr and Holley's own announcements ("Holley Performance Products Acquires MSD Group"). The 2015 Cerberus security agreement recorded at Reel 036664/0148 lists MSD LLC alongside Holley Performance Products Inc., QFT Holdings Inc., Holley Performance Systems Inc. — i.e., an intercompany credit facility coinciding with the acquisition. Not dissolved; not in bankruptcy on the record reviewed.

Assignment timeline

Chronological. All entries below are recorded instruments appearing in the patent's Legal Events table. Note that the "Assignee" on a Security Agreement / Security Interest is a lienholder, not an owner — no title passes.

• 2012‑05‑11 (executed) / recorded 2012‑05‑11 — Reel 028198/0095

  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: Richard K. Bennett; Douglas D. Webber
  • Assignee: Autotronic Controls Corporation, Texas
  • Correspondent: not reproduced in the source used — see sourcing note
  • Context: initial inventor‑to‑employer assignment; no capitalization event, no third party.

• 2013‑12‑16 (executed) / recorded 2013‑12‑16 — Reel 031789/0664

  • Conveyance: Assignment
  • Assignor: Autotronic Controls Corporation
  • Assignee: MSD, LLC, Texas
  • Correspondent: not reproduced in the source used
  • Context: internal reorganization / brand‑entity consolidation into the MSD LLC name — not an arm's‑length sale.

• 2013‑12‑16 (executed) / recorded 2013‑12‑17 — Reel 031834/0064

  • Conveyance: Security Agreement
  • Assignor: MSD LLC
  • Assignee: Monroe Capital Management Advisors, LLC, as Agent
  • Correspondent: not reproduced in the source used
  • Context: securitization — collateral pledge of the MSD patent portfolio; lien only.

• 2013‑12‑16 (executed) / recorded 2014‑03‑12 — Reel 032420/0252

  • Conveyance: Security Interest
  • Assignor: MSD LLC
  • Assignee: Z Capital Commercial Finance, L.L.C., Illinois
  • Correspondent: not reproduced in the source used
  • Context: securitization — a second lender taking a security interest in the same portfolio (Monroe and Z Capital are the two lenders identified as the MSD sellers in the 2015 Holley deal).

• 2015‑09‑22 (executed) / recorded 2015‑09‑22 — Reel 036664/0148

  • Conveyance: Patent Security Agreement
  • Assignors: Holley Performance Products Inc.; QFT Holdings, Inc.; Holley Performance Systems, Inc.; and others (incl. MSD LLC; Powerteq LLC; Accel Performance Group LLC)
  • Assignee: Cerberus Business Finance, LLC, as Collateral Agent
  • Correspondent: not reproduced in the source used
  • Context: securitization — post‑acquisition refinancing of the combined Holley/MSD group; lien only.

• 2015‑09‑22 (executed) / recorded 2015‑09‑24 — Reel 036674/0907

  • Conveyance: Release of Security Interest in Patents
  • Assignor: Z Capital Commercial Finance, L.L.C.
  • Assignee (released party / owner): MSD LLC, Kentucky
  • Correspondent: not reproduced in the source used
  • Context: lien release — prior MSD financing lien cleared in connection with the Holley acquisition.

• 2015‑09‑22 (executed) / recorded 2015‑09‑24 — Reel 036687/0051

  • Conveyance: Release of Patent Security Interest
  • Assignor: Monroe Capital Management Advisors, LLC
  • Assignee (released party / owner): MSD LLC, Kentucky
  • Correspondent: not reproduced in the source used
  • Context: lien release — the other pre‑acquisition MSD lien cleared.

• 2018‑10‑26 (executed) / recorded 2018‑11‑05 — Reel 047419/0953

  • Conveyance: Release by Secured Party
  • Assignor: Cerberus Business Finance, LLC
  • Released: Holley Performance Systems, Inc.; Holley Performance Products Inc.; Powerteq LLC; Accel Performance Group LLC; QFT Holdings, Inc.; MSD LLC
  • Correspondent: not reproduced in the source used
  • Context: lien release — Cerberus facility retired and replaced by the UBS/AEA financing recorded days later.

• 2018‑10‑26 (executed) / recorded 2018‑11‑06 — Reel 047429/0343

  • Conveyance: Security Interest
  • Assignors: Flowmaster, Inc.; APR, LLC; Accel Performance Group LLC; and others (incl. MSD LLC)
  • Assignee: UBS AG, Stamford Branch, as Collateral Agent
  • Correspondent: not reproduced in the source used
  • Context: securitization — first‑lien credit facility across the Holley brand family; lien only.

• 2018‑10‑26 (executed) / recorded 2018‑11‑18 — Reel 048147/0510

  • Conveyance: Security Interest
  • Assignors: Flowmaster, Inc.; APR, LLC; Accel Performance Group LLC; and others (incl. MSD LLC)
  • Assignee: AEA Debt Management LP, Second Lien Collateral Agent
  • Correspondent: not reproduced in the source used
  • Context: securitization — second‑lien tranche alongside UBS.

• 2018‑10‑26 (executed) / recorded 2018‑11‑18 — Reel 048475/0125

  • Conveyance: Corrective Assignment
  • Assignors: Flowmaster, Inc.; APR, LLC; Accel Performance Group LLC; and others
  • Assignee: UBS AG, Stamford Branch, as Collateral Agent
  • Correspondent: not reproduced in the source used
  • Context: correction only — "corrective assignment to delete patent numbers previously recorded at Reel 047429, Frame 0343." This is housekeeping, not a transfer. (Worth noting: this correction is portfolio‑level and does not tell us whether '353 itself was added or deleted from that lien schedule.)

• 2021‑11‑18 (executed) / recorded 2021‑11‑19 — Reel 058214/0174

  • Conveyance: Security Interest
  • Assignors: Holley Performance Products Inc.; MSD LLC; Powerteq LLC; and others (incl. Accel, B&M Racing & Performance Products, Drake Automotive Group)
  • Assignee: Wells Fargo Bank, National Association, North Carolina
  • Correspondent: not reproduced in the source used
  • Context: securitization — refinancing replacing UBS as first‑lien collateral agent.

• 2021‑11‑18 (executed) / recorded 2021‑11‑24 — Reel 058944/0279

  • Conveyance: Release by Secured Party
  • Assignor: AEA Debt Management LP, as Second Lien Collateral Agent
  • Released: MSD LLC; Holley Performance Products Inc.; Holley Performance Systems, Inc.; Powerteq LLC; Racepak LLC; Accel Performance Group LLC; APR, LLC; Flowmaster, Inc.; High Performance Industries, Inc.
  • Correspondent: not reproduced in the source used
  • Context: lien release — second‑lien facility retired.

• 2021‑11‑18 (executed) / recorded 2021‑11‑24 — Reel 058948/0926

  • Conveyance: Release by Secured Party
  • Assignor: UBS AG, Stamford Branch, as First Lien Collateral Agent
  • Released: same Holley/MSD group entities as above
  • Correspondent: not reproduced in the source used
  • Context: lien release — first‑lien facility retired on the Wells Fargo refinancing.

Bottom line on title: there is no post‑2013 assignment of the patent itself in the record. Every instrument after Reel 031789/0664 is a lien, lien release, or correction. Title has sat with MSD LLC since 2013‑12‑16, and MSD LLC has been a Holley subsidiary since the September 2015 acquisition. Maintenance fees were paid (4th year 2022‑03‑23; 8th year 2026‑04‑09, large entity), so the patent is in force; adjusted expiration shown as 2035‑12‑17 (PTA).

Timeline diagram

timeline
    title Ownership of US 10094353
    2012 : Filed by Bennett and Webber
         : Assigned to Autotronic Controls
    2013 : Assigned to MSD LLC
         : Monroe Capital security agreement
    2014 : Z Capital security interest
    2015 : Holley acquires MSD Group
         : Cerberus security agreement
         : Prior MSD liens released
    2018 : Patent issues as US 10094353
         : UBS and AEA security interests
    2021 : Wells Fargo security interest
         : UBS and AEA liens released
    2026 : Holley sues Aces Fuel Injection

NPE / troll-pattern signals

Litigation cross‑reference. The Google Patents page for this patent carries a related litigation entry: US case filed in the Eastern District of Tennessee, docket 1:26‑cv‑00059, linked via Unified Patents' litigation data. Public docket sources (RPX Insight; Ex Parte AI Lab; Justia) identify that docket as Holley Performance Products Inc. v. Aces Fuel Injection, Inc., E.D. Tenn., filed 2026‑03‑06, nature of suit 830 (Patent).

One caveat I will not paper over: the Ex Parte complaint‑analysis extract for 1:26‑cv‑00059 lays out infringement charts for the '515 patent (independent claim 9) and the '083 patent (independent claim 1) as the lead patents, both Holley electronic‑fuel‑injection throttle body patents from the later 2017/2018 families, and quotes the accused Aces Killshot Fusion EFI System (four bores, fuel distribution ring with a plurality of apertures). I cannot confirm from the material retrieved that US 10,094,353 is among the counts actually pleaded in that complaint — only that the USPTO/Google litigation feed associates this docket with this patent. Treat '353's involvement in the 2026 suit as linked but unverified; the ownership analysis above does not depend on it either way.

Verdict

Operating‑company assertion.

MSD LLC — the assignee of record since the internal reorganization at Reel 031789/0664 (executed 2013‑12‑16) — is an operating automotive‑performance brand that ships EFI throttle body products practice‑in the disclosure, and it has been a Holley Performance Products company since the 2015‑09‑23 acquisition (evidenced on the assignment record by the Holley + MSD joint Cerberus pledge at Reel 036664/0148, followed by releases of the Monroe and Z Capital liens at Reels 036687/0051 and 036674/0907). Every other instrument in the chain is a lien, lien release, or correction from conventional lenders — Monroe, Z Capital, Cerberus, UBS, AEA, Wells Fargo (Reels 031834/0064, 032420/0252, 047429/0343, 048147/0510, 048475/0125, 058214/0174, 058944/0279, 058948/0926) — which is the signature of a leveraged operating company, not of a patent monetization vehicle. All eight NPE tells score not present or unclear; zero strong signals, zero weak signals substantiated beyond naming. The assertion, if and to the extent '353 is pleaded, is a competitor‑versus‑competitor product dispute brought by Holley against Aces Fuel Injection in E.D. Tenn. No. 1:26‑cv‑00059.

Verify at: Assignment Center search for this patent — https://assignmentcenter.uspto.gov/ (patent number search; also indexed at https://assignment.uspto.gov/patent/index.html) · Google Patents legal events — https://patents.google.com/patent/[US10094353B2](/patent/US10094353B2)/en · RPX Insight docket — https://litigation.rpxcorp.com/litigation/tnedce-[123355](/patent/123355)-holley-performance-products-v-aces-fuel-injection

I'll research the prior-art citations for US 10,094,353 B2. Let me start with parallel searches.

Let me research the remaining key references.

Tool-limit note: I exhausted my search-call budget partway through this task. Below, I ground every reference in the citation list that appears on the face of US 10,094,353 B2 (authoritative) plus the references I was able to verify via Google Patents/Espacenet/FPO snippets. For four references (US 5,103,795; US 4,401,095; US 3,669,424; and the Ford '310 publication) my final verification searches did not return before the cap; I flag those explicitly rather than assert unverified detail.

Prior-Art Analysis for US 10,094,353 B2

0. USPTO confirmation of the patent number

A search for the literal number 10094353 resolves only to US 10,094,353 B2, "Throttle body fuel injection system with improved fuel distribution," App. No. 13/470,121, filed 2012-05-11, granted 2018-10-09, inventors Richard Kirk Bennett / Douglas David Webber, current assignee MSD LLC. No other patent shares that number. Sources: https://patents.google.com/patent/[US10094353B2](/patent/US10094353B2)/en ; https://patents.justia.com/patent/10094353

Analytical caveat up front. Anticipation under §102 requires a single reference disclosing every element of a claim, arranged as claimed. The point of novelty of the '353 patent is the annular fuel-distribution ring disposed in the bore with a plurality of openings at its lower end in fluid communication with the injector (claim 1 element set), plus the two-piece insert/housing ring and non-Venturi straight-wall geometry (dependent claims 4–9). After reviewing each cited reference, my assessment is that no cited reference anticipates independent claim 1 or claim 12 in full. The cited art is primarily §103 (obviousness) material and element-level art. I give the honest "potential §102" mapping per reference below and say so plainly where a reference discloses only some elements.

For orientation, the elements of claim 1 are:

• (a) throttle body assembly with a bore therethrough, throttle valve in the bore, bore defining inlet and outlet;
• (b) fuel injector mounted to the throttle body assembly;
• (c) a ring in the bore, with upper/lower ends and a circular wall having inner and outer circumferences;
• (d) a plurality of openings formed in the lower end of the ring, each in fluid communication with the injector; fuel injected through those openings.

Claim 12 is the method analogue (provide such an assembly; mount atop the intake manifold).

1. Tier 1 — Most relevant references

1.1 US 5,809,972 A — Grant, "Venturi-assisted fuel injection carburetor system"

• Full citation: US 5,809,972 A; filed 1997-07-23 (priority 1996-06-21); published/granted 1998-09-22; inventor Barry Grant; IPC F02M 51/02 / 71/00.
• Brief description (verified): Fuel at regulated pressure passes from fuel injector(s) seated in mounting blocks bolted to the sides of a conventional 2- or 4-barrel carburetor center section. Each injector is in fluid communication with a booster venturi ring suspended in each carburetor barrel; the injectors intermittently deliver high-pressure pulses of fuel to the booster venturi rings, which disperse the fuel into the airstream (the suspended ring + barrel wall constriction create the low-pressure, high-velocity zones that atomize the fuel). Source: https://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=[5809972A](/patent/5809972A) ; https://patents.google.com/patent/[US5809972A](/patent/US5809972A)/en ; https://www.freepatentsonline.com/[5809972](/patent/5809972).html
• Why it matters: This is the closest art on the "ring in a bore fed by an injector" concept. The '353 specification itself cites Grant as a design that "utilize[s] venturis akin to carburetor annular boost venturis to create low pressure zones."
• Potential §102 mapping:
  • Claim 1: Closest reference, but I assess it does not anticipate. It discloses elements (b) injector mounted to the throttle structure and (c) an annular ring suspended in the barrel, and arguably a bore with a throttle valve, i.e., preamble elements (a). The fatal gap is element (d): Grant's ring is a booster venturi that disperses fuel at/near its throat (inner sidewall), not through openings formed in the ring's lower end. It also teaches toward a Venturi constriction, directly contrary to dependent claims 8 and 9.
  • Claims 8 and 9: Because Grant expressly relies on the Venturi effect (constriction), it cannot anticipate the "substantially constant diameter … to minimize any Venturi effect" limitations — it is affirmative contrary art on those claims (useful for §103 in the opposite direction: it shows the inventors deliberately avoided what Grant taught).
  • Bottom line: Strong §103 reference against claim 1; not a clean §102 reference.

1.2 US 7,735,475 B2 (and its publication US 2009/0145406 A1) — Farrell et al., "Fuel injection body sized to replace carburetor body"

• Full citation: US 7,735,475 B2; filed 2007-10-12 (prov. 60/979,702, 2007-10-12; 61/052,903, 2008-05-13); granted 2010-06-15; inventors Kenneth William Farrell, Warren Lamont Duff; current assignee Aces Fuel Injection Inc. (i.e., the defendant in the 2026 Holley case). Companion publication US 2009/0145406 A1 (2009-06-11).
• Brief description (verified): A throttle body (main body with side surfaces, top and bottom) sized to bolt onto a standard 4150-type manifold, with two/four air passages extending top-to-bottom, butterfly throttle valves, fuel injectors mounted to the sides and aimed at the air passages, an integrally mounted small computer (ECU), and an idle-air circuit. Source: https://patents.google.com/patent/US7735475 ; https://www.freepatentsonline.com/y2009/0145406.html
• Why it matters: This is the "FIG. 2 prior art" throttle body expressly discussed and distinguished in the '353 specification (the patent quotes Farrell col. 3 ll. 58-59 on positioning injectors above the throttle blades). It is the single most on-point structural prior art for the throttle-body-instead-of-carburetor architecture.
• Potential §102 mapping:
  • Claim 1: Anticipates the preamble — throttle body assembly (a), bore/throttle valve, injector mounted to the body (b) — and substantively reads on claim 3 subject matter (injectors positioned above the throttle plates, i.e., upstream of the throttle valve). It does not disclose the ring (c) or the lower-end openings (d), so it cannot anticipate claim 1 or 12.
  • Claim 3 (dependent): Farrell's injectors above the throttle blades is strongly supportive of, but not by itself anticipatory of, the "ring upstream of the throttle valve" limitation (because the ring itself is absent).
  • Bottom line: Core §103 reference for the apparatus architecture; no §102 anticipation of the ring claims.

1.3 US 2011/0132310 A1 — Ford Global Technologies, "System for improving gas distribution in an intake manifold"

• Full citation: US 2011/0132310 A1; filed 2010-04-26; published 2011-06-09; assignee Ford Global Technologies LLC.
• Brief description (from the citation list only; I could not fully verify the disclosure before my search cap): Directed to improving fuel/gas distribution within an intake manifold — a field directly analogous to the '353's stated object ("optimal fuel distribution"). The title and classification suggest in-manifold distribution hardware (potentially a flow-directing insert/sleeve in a runner), which is worth close reading against claim 1(c)–(d) and claim 2 (coaxial ring).
• Potential §102 mapping: Unverified. If the reference discloses an annular distribution element with outlets in a runner, it becomes a serious claim 1 / claim 2 candidate; if it is control/plumbing only, it is §103/background. I flag this as the reference requiring the most verification.

1.4 US 6,467,465 B1 — Lorts, "Throttle body fuel injector adapter manifold"

• Full citation: US 6,467,465 B1; filed 2001-01-10; granted 2002-10-22; inventor Anthony R. Lorts.
• Brief description (verified): A manifold block holding bottom-fed, side-ejecting gaseous injectors, mounted atop a throttle body; fuel is carried by tubes to "optimal points near the engine inlet," and one or more injectors may be dedicated to injecting fuel into the idle air control (IAC) circuit of a throttle body at idle. Source: https://patents.google.com/patent/US6467465 ; https://patentimages.storage.googleapis.com/60/5c/18/94d78d7435d0ad/US6467465.pdf
• Why it matters: Notably relevant to the IAC-injection concept that is described in the '353 specification but not claimed in the '353's claims (it is claimed in the sibling US 9,845,740). Lorts also shows a "gasoline injector mounted above the butterfly throttle plate."
• Potential §102 mapping: Discloses injector-above-throttle-plate (claim 3 element) and fuel delivery to the IAC circuit; does not disclose the ring (c) or lower-end openings (d), so no anticipation of claims 1 or 12, and no anticipation of the '353's actual claim set (which omits the IAC subject matter). It is background §103 art.

1.5 US 4,348,338 A — Martinez et al., "Injection-type pressure-freed carburetor"

• Full citation: US 4,348,338 A; filed 1978-10-18 (App. 06/251,060); granted 1982-09-07; inventor Jose L. P. Martinez. (Status: Expired – fee related.)
• Brief description (from citation list; Google Patents confirms biblio): An injection-type, "pressure-freed" carburetor — a carburetor-format device using injection rather than float-bowl pressure differential to feed fuel. Source: https://patents.google.com/patent/[US4348338A](/patent/US4348338A)
• Potential §102 mapping: It is a carburetor-format injector-fed charge former, so it is relevant to the conversion/retrofit concept and to the general "inject fuel into a throttle bore" idea. Absent a ring-with-lower-openings disclosure, it does not anticipate claim 1 or 12. §103/background art.

2. Tier 2 — Fuel/air mixing and atomization devices (analogous "ring/nozzle in the airstream" art)

These are the references most likely to bear on dependent claims 6–11 (groove-defined openings; straight-wall/anti-Venturi; downward-facing openings; opening area > injector discharge area).

3. Tier 3 — Control/ECU art, adapters, and design/ornamental art

These are relevant only to the '353 specification's ECU/IAC discussion (which is NOT in the '353 claims) or are non-anticipatory as to the claimed structure.

4. Non-patent citation

Professional Products — Powerjection™ III Installation Instructions & User Manual for kits 70020/70021/70026/70027 and 70028/70029 plus 70120–70129; © 2010, www.professional-products.com.

• Brief description: A commercial throttle-body EFI retrofit manual predating the '353 priority date.
• Potential §102 mapping: As a printed publication under pre-AIA §102(b) (©2010, >1 yr before the 2012-05-11 filing), it is §102(b) prior art to the extent it discloses the claimed structure. A retrofit throttle-body EFI manual would likely show a throttle body with bores, throttle plates, and injectors — reading on the preamble/claim 3 — but I have not verified that it discloses the ring with lower-end openings, so no confirmed anticipation. Worth obtaining the full manual to assess whether it discloses an annular distribution ring.

5. Consolidated §102 answer

Overall conclusion: Every reference cited on the face of US 10,094,353 B2 is pre-2012 and thus within the §102 window, but none of them, singly, discloses all elements of independent claim 1 or claim 12 — specifically, none has been shown to disclose the annular distribution ring mounted in the throttle bore with a plurality of openings at the ring's lower end fluidly coupled to the injector. The cited art is best characterized as:

• §102-relevant to the preamble of claim 1 and to claim 3: US 7,735,475 (Farrell) and its publication US 2009/0145406 A1; US 6,467,465 (Lorts).
• The single closest ring-based reference, but contrary on Venturi: US 5,809,972 (Grant).
• §103/background (mixing, gaseous-fuel, ECU, design, adapters): US 4,401,095; US 5,103,795; US 5,408,978; US 5,269,283; US 5,377,646; US 6,250,261; US 2008/0184964; US 5,200,900; US 5,523,948; US 5,479,897; US 2012/0132168; US 2010/0147242; US 2012/0048962; US 2013/0042836; US D659,714; and the Powerjection III manual.

6. References I could NOT verify (explicit)

Per my operating rule, I am flagging rather than fabricating:

• US 4,401,095 / US 5,103,795 / US 5,408,978 / US 5,269,283 / US 5,377,646 / US 6,250,261 / US 2008/0184964 / US 3,669,424 — I have the bibliographic data from the '353 citation list itself (authoritative for citation/date), but I did not retrieve and read the full disclosures before hitting the search cap, so my element-level mappings above are provisional.
• US 2011/0132310 (Ford) — highest-priority item to verify; its "gas distribution in an intake manifold" subject matter could be the closest structural art on claim 1 after Grant.
• US 2005/0132168-style Kennedy publication (US 2012/0132168 A1) — requires verification because of the unusual 2005 effective filing date.
• I did not independently confirm the Professional Products Powerjection III manual's disclosure.

Recommended next steps for a definitive §102/§103 position: (1) pull the full-text PDFs for US 4,401,095, US 5,103,795, US 2011/0132310, and US 2008/0184964 from USPTO PatentCenter/Patent Public Search; (2) confirm the prosecution history (Examiner's reasons for allowance on the ring-with-lower-end-openings limitation) in the 13/470,121 file wrapper; and (3) pull the PACER docket for Holley Performance Products Inc. v. Aces Fuel Injection, Inc., No. 1:26-cv-00059 (E.D. Tenn.) to see whether US 10,094,353 is actually asserted and, if so, which claims — since the accused Farrell-assigned product line (Aces) is itself the assignee of the closest cited prior art (US 7,735,475), which may bear on invalidity.

I'll ground this obviousness analysis in the actual cited prior art rather than working from memory. Let me pull details on the key references from the patent's face.

Good — this pulled up a highly relevant sibling reference. Let me now pull the remaining structural references, especially the ones that teach ring/sleeve fuel distribution.

Obviousness Analysis — U.S. Patent No. 10,094,353 B2

Under 35 U.S.C. § 103(a) (pre-AIA), using the prior art of record on the patent face

Note on scope and dates. This analysis is built from the "Citations (22)," "Non-Patent Citations (1)," and "Family Cites Families (47)" listings on the face of US 10,094,353, as instructed. I attempted to retrieve the full disclosure of the most structurally relevant ones; I retrieved four, and I flag explicitly below which ones I could not verify. One minor inconsistency to flag: the earlier sections in this analysis were dated April 26, 2026, while the system context now reads 2026-09-29. Nothing in this section turns on that difference.

Statutory framework. The application was filed 2012-05-11, before the AIA first-inventor-to-file effective date. Pre-AIA § 103(a) therefore governs, with KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) supplying the controlling obviousness gloss. The relevant date for the level of ordinary skill is the 2012-05-11 filing date (no priority claim to an earlier date appears on the face; the family's earliest date is also 2012-05-11).

1. Person of Ordinary Skill in the Art (PHOSITA)

For this record I would define the PHOSITA as a person with a bachelor's degree in mechanical or automotive engineering and 2–5 years of experience designing carburetors, throttle bodies, and electronic fuel-injection hardware for the automotive aftermarket — the field is expressly the retrofit/high-performance segment (the specification targets "muscle cars and hot rods," square-bore 4150/4160 manifolds, and Ford/GM/Mopar engines). That person reads carburetor patents and throttle-body EFI patents side-by-side; the patent's own Background section does exactly that.

2. The prior art of record — what I could and could not verify

⚠️ Excluded as non-prior art. Do not use US 9,376,997 B1 / US 11,391,255 B2 / US 11,395,255-type Farrell patents ("EFI throttle body with side fuel injectors," sleeve with annular passage and downward-angled orifices press-fit in the bore) or US 11,215,159 / US 11,308,383. Their earliest effective dates are 2016, well after the '353's 2012-05-11 filing date. They are later art against which the '353 family may itself be prior art — not usable in an obviousness attack on the '353. I mention them only because they mark where the art was moving.

3. Element-by-element mapping of the independent claims

The crux. Claims 1 and 12 differ from this record in essentially one respect: the location and orientation of the discharge — a plurality of openings at the ring's lower end, arranged to dispense fuel coaxially from that end (claim 12), rather than through the ring's interior side wall at a venturi throat as in the admitted FIG. 1 carburetor, Grant, and Davis. Everything else in claim 1 is squarely in the record.

4. Combinations rendering the claims obvious

⭐ Combination A (strongest): Farrell '475 + Davis '878 [+ Grant '972]

Why combine. All three are in the same field and address the same problem. Farrell '475 positions its injectors "to direct fuel to cover the upper surface of the throttle blade to improve fuel atomization" and is a bolt-on replacement for a 4150 carburetor. Grant '972 states the objective bluntly: "a fuel system combining the high atomization of a carburetor and the precise fuel metering of fuel injectors would be desirable," and expressly converts a conventional carburetor by replacing the float bowls with injector mounting blocks. Davis '978 is a bolt-on mixer "easily mounted to an existing automobile engine… without complex and costly modifications to the engine," whose express purpose is to entrain fuel uniformly into the airstream using an annular plenum feeding an annular array of orifices in a press-fit ring. The '353 claims the same benefit ("superior mixing for even distribution to the cylinders"). KSR: "[i]f a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious."

Claim mapping.

• Claim 1 — Farrell supplies (a) and (b) and the retrofit TBI context; Davis supplies (c) and (d) in substance: a ring 32 press-fit into a bore-like channel, with a plurality of openings (annular array of holes 39) fed from an annular plenum 23 that is itself fed by a fuel conduit. Gap: Davis's holes are through the wall rather than "in said lower end." KSR rationale: relocating the outlet from the ring's side wall to its lower end is the predictable use of a known element, and carries no change in principle of operation — the injector still meters, the ring still distributes.
• Claim 2 (coaxial) — inherent; Farrell's passages are cylindrical; Davis's ring is coaxial with channel 19. Obvious.
• Claim 3 (ring upstream of throttle valve) — Farrell's injector receptacles discharge into the upper cylindrical portion 156, above the throttle-valve shaft aperture 182; Grant's booster ring sits above the throttle valve in the barrel. Obvious.
• Claim 4 (two-piece: ring-shaped insert in outer ring-shaped housing) — Davis '978 discloses this almost verbatim: "a control ring 31/32 which is press fitted through the bottom opening 21 of the housing," seated within the tubular wall 18. That is an insert ring in an outer housing. Very strong.
• Claim 5 (conduit fluidly coupling outlets to injector; outer housing and conduit integral with the throttle body casting) — Farrell: the injector receptacles 180 and interconnecting passages are bored into the main throttle body 102 and the fuel system is "fully integrated into the [throttle body]." Grant: "one of several fuel conduits formed in the carburetor center section which each leads to a particular booster venturi ring," with "no further carburetor alteration… necessary." Very strong — arguably met by Grant alone.
• Claim 6 (openings defined by axial grooves in the insert OD and/or housing ID) — not squarely disclosed; Davis uses drilled holes. KSR: forming a plurality of outlets as milled grooves rather than drilled holes is a routine manufacturing/design choice, and the family cites (Grant's replaceable venturi sleeves, US 5,863,470; replaceable booster venturis, US 5,807,512) show grooved/sleeved fuel passages were conventional in carburetors. Obvious as a design choice; moderate strength.
• Claim 7 (circumferential groove fluidly connecting the axial grooves to the conduit) — Davis '978 maps almost exactly: annular groove 22 in the tubular wall partially defines plenum 23, which is in fluid communication with the gas intake orifice 17 (the inlet conduit) and with the annular array of holes 39. Substituting a circumferential groove for Davis's annular plenum is a matter of nomenclature/geometry. Strongest dependent-claim mapping in the entire analysis.
• Claims 8, 9, 11 — see § 6 below (the genuinely contestable ones).

Motivation, restated for a petition. (i) Same field (F02M fuel supply to engines) and same problem (mixing/atomization and even cylinder-to-cylinder distribution). (ii) Davis's mixer and Farrell's TBI body are both bolt-on retrofit devices for the aftermarket, addressing identical installation constraints — the "market forces" and "design incentive" rationale of KSR. (iii) Grant expressly bridges the architectures by teaching injected fuel delivered into a suspended ring in each bore, thereby supplying the very motivation to put an annular fuel-distribution ring inside a throttle bore rather than relying on a bare injector plume. (iv) No change in principle of operation; no unpredictable result.

Combination B: Grant '972 + Farrell '475 (for claims 1–3, 10, 12, and 5)

Grant alone supplies "a ring suspended in each barrel" that is fed by an injector and that "disperses the fuel into the airstream," plus integral fuel conduits in the center section; Farrell supplies the throttle body/valve/injector architecture and the bolt-on-to-a-manifold context. This combination is the cleanest for claim 5 (conduits integral with the casting) and for the claim 12 method (Grant's own claim 13 is a method of converting a carburetion system to fuel injection; Farrell's body "can be bolted to most factory and after-market manifolds").

Gap. Grant's ring is a venturi, and its discharge is at the throat/interior wall — squarely against claims 8, 9 and arguably 10. That weakness is why Combination A (which adds Davis for the non-venturi annular-orifice ring) is preferable.

Combination C: Admitted art (specification) + Farrell '475

The '353's own Background § 2 admits: a carburetor barrel with primary and annular boost venturis and orifices 21 at the throat within the annular venturi (16) that atomize fuel drawn into the air stream; and the Farrell FIG. 2 TBI body. These are § 102(a)/(b) admissions usable as prior art under § 103. They establish that placing a ring in an engine air bore with a plurality of fuel outlets was known; the only remaining question is the location of the outlets. Useful as a supporting rationale, not as a standalone combination.

5. Claim-by-claim obviousness summary

6. The two contestable limitations, and how they fare

Claims 8 & 9 — "substantially constant diameter… to minimize any Venturi effect"

This is where a patent owner will fight, and on this record it is a defensible position: the two most on-point references affirmatively use constrictions. Farrell '475: "The profile of each of the passages… preferably defines a venturi… constricted in the middle and flared at both ends." Grant '972: the constriction is what "decrease[s] the pressure of the airstream, resulting in greater atomization."

Three counters, in order of persuasiveness:

1. Claims 1 and 12 do not require it. The anti-venturi limitations are only in dependent claims 8 and 9. A § 103 attack on the independent claims is unaffected by this dispute.
2. KSR "functional change / element no longer needed." Grant's constriction exists to lift and atomize fuel drawn by manifold vacuum. Once the fuel is delivered by a pressurized injector (as in Farrell, Grant's own conversion, and the '353), the constriction's fuel-handling function is obviated, and the remaining effect is an unwanted pressure drop. Removing a structure whose purpose has been eliminated is a classic KSR rationale ("the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results"), and the claimed benefit — "minimal pressure drop" — is expressly framed in the specification as the predictable consequence.
3. The '353's own admissions supply the problem to be solved. The specification states that venturis cause "imprecise fuel delivery due to the propensity to draw fuel out of the fuel passages downstream of the injectors during 'off' periods" and "a greater risk for the accumulation of icing." KSR: "any need or problem known in the field… and addressed by the patent can provide a reason for combining the elements." A reference need not prefer the solution to render it obvious; disclosure of a single venturi embodiment does not, without more, discredit the alternative.

Candid assessment: a district court could go either way on claims 8–9. The strongest art position requires a reference expressly disclosing a constant-diameter (straight-bore) throttle body — precisely the kind of product shown in the Powerjection III manual and in straight-bore aftermarket throttle bodies. Obtaining that document is the key step.

Claim 11 — "total area of said openings is greater than a discharge area of said fuel injector"

The specification says the openings' total area is ~50% larger "so as to lower the kinetic energy of the fuel droplets entering the air stream." That is a predictable consequence of flow continuity (larger combined area → lower velocity → lower kinetic energy), i.e., optimization of a result-effective variable with a result the law treats as obvious absent unexpected results. Davis '978 also expressly treats hole count/size as a tunable parameter ("the control ring having a preselected number and size of holes for that particular engine"). Note the counter-tension: later Farrell art states a desire "not unduly restrict flow while building just enough backpressure to create spray through the orifices" — i.e., the art pulls in the opposite direction on this parameter, which a patent owner may use to argue the claimed range was non-obvious. That counterargument only works on claim 11, however, and the claim recites a bare inequality (">"), not a critical range.

7. Objective indicia (Graham factor 4)

No evidence of secondary considerations appears in the record I reviewed. Note that MSD/Holley commercial success in the TBI retrofit market is likely provable — but the nexus problem is severe: the features that plausibly drove commercial success (the IAC crossover ports below the fuel ring, and the ECU "feed-forward" algorithm that increases injector pulse width as the IAC opens) are described in the specification but recite nothing in the granted claims of the '353; that subject matter is claimed in the sibling US 9,845,740 B2. Commercial success attributable to unclaimed features carries no weight. Expect the patent owner to try to bridge this with specification-embedded language — a standard nexus fight.

8. ⚠️ Two escalation items — these could change the analysis materially

(1) US 7,735,475's "auxiliary fuel injector plate / adaptor" disclosure. The retrieved abstract of Farrell '475 states: "An adaptor is positioned within the central passageway. The adaptor comprises a plurality of openings. A first fuel injector extends into the central passageway." If the '475 specification and Fig. 13 show that adaptor as a ring-shaped insert with its openings distributing fuel into the air stream, then Farrell '475 alone may approach claim 1 — collapsing Combinations A–C and removing the entire "lower end" gap. Farrell '475 is the assignee's own art of record, so this cuts only one way. I strongly recommend pulling the full '475 specification (Figs. 13 and the accompanying text) before relying on the "lower-end discharge" gap. I could not verify this from the retrieved material and am not asserting it as established.

(2) The Powerjection III manual. It is the only item cited by the examiner as non-patent literature, meaning it was on the record and considered. It is a printed publication predating the 2012 filing date and describes a competing retrofit TBI product. If it depicts an annular fuel-distribution ring or downward-discharging outlets in a throttle bore, claims 1, 10 and 12 become very difficult to defend.

9. Strategic note tying back to the litigation section (possible contradiction to flag)

While retrieving the prior art I noticed that the Google Patents record for US 7,735,475 B2 — the primary prior-art reference on the '353's face — now lists its current assignee as "Aces Fuel Injection Inc" / "WALD DIVERSIFIED Corp." (Google Patents expressly disclaims the accuracy of its assignee listings, so treat this as a lead.) If accurate, the accused infringer in Holley Performance Products Inc. v. Aces Fuel Injection, Inc., No. 1:26-cv-00059 (E.D. Tenn.) owns the Farrell prior-art patent that the Patent Office cited against the asserted patent. That would give Aces a ready-made defense and counterclaim posture directed at the '353 family — a materially different picture from the "infringement allegations keyed to the '515 and '083 patents" described in the earlier litigation section. I cannot confirm it, and it does not change the § 103 analysis above, but it is worth verifying against the assignment records before the earlier litigation section is relied upon.

Also worth noting for timing: because the '353 issued in 2018 and the complaint was served in 2026, an IPR petitioner would have one year from service of the complaint to file — the § 315(b) window is open, and the 2012 priority date means there is no PGR option.

10. Bottom line

• Claims 1 and 12 are vulnerable but not clearly invalid on the retrieved record. US 7,735,475 + US 5,409,878 (and/or US 5,809,972) supply every element except an express disclosure of fuel outlets at the ring's lower end dispensing coaxially, which is the point of novelty. The combination is supported by a strong same-field/same-problem/same-injector-replaces-vacuum motivation and by KSR's predictable-use and design-choice rationales, but the gap is real.
• Dependent claims 4, 5, 7 (and arguably 11) are the weakest links. US 5,409,878's press-fit control ring in an outer housing with an annular groove feeding an annular array of orifices maps onto claims 4 and 7 with unusual precision; Grant's integral center-section fuel conduits map onto claim 5.
• Claims 8 and 9 are the patent owner's best ground. The two closest references affirmatively use venturi constrictions, making a teaching-away argument available. The counter relies on KSR's "element no longer needed" and "problem known in the field" rationales plus the specification's own criticism of venturis.
• Two documents could flip the whole analysis: the full disclosure of Farrell '475's auxiliary-injector-plate adaptor, and the Professional Products Powerjection III manual (2010). Neither is dispositive on what I retrieved; both should be pulled before any § 103 position is finalized.

Items I could not verify, listed so they are not mistaken for findings: the full text of US 4,348,338; US 4,401,095; US 5,269,283; US 3,669,424; US 5,479,897; US 5,200,900; US 5,523,948; US 6,467,465; US 2010/0147242; US 2012/0132168; US 2008/0184964; US 8,555,866; US 2013/0042836; US 5,863,470 and US 5,807,512; the Powerjection III manual; and the full '475 specification. Several of these are plausible sources for the "downward-facing outlet" and "constant-diameter bore" limitations, and their contents could materially strengthen or weaken the conclusions above.