Legendary 1:4 Scale Conley 427 V8
The Official Conley 427 Revival
A fully functional 1:4 scale V8 engine - reborn by ACM, Inc.
A Legend Returns
The Conley 427 isn't just a miniature engine - it's a legend. First introduced by Gary Conley in the early 1990s, this fully operational 1:4 scale V8 engine stunned the modeling and machining world with it's performance, realism, and craftsmanship. For decades, it's remained the holy grail of miniature engines.
Now it's back - officially.
The Rights, the Molds, the Mission
In 2015, ACM,Inc. acquired the full rights to the Conley 427 engine, including the original diecast molds and key engineering documentation. We are now the official stewards of the Conley legacy - and are committed to reviving this historical engine with care, precision, and integrity.
We're not just restoring the Conley 427 - we're bringing it back into limited production with modern engineering and the same iconic soul.
"We're not just rebuilding the engine. We're preserving it's legacy - and bringing it into a new generation of craftsmanship."
In Collaboration with Gary Conley
While no longer actively producing engines, Gary Conley remains a respected and supportive figure in this revival. With his blessing and historical insight, we are proud to continue the engine he pioneered - honoring both the original design and the man behind it.
Reverse Engineering the Future
We are not tearing down the original engine. Instead, We're combining what's already known with careful reverse engineering of undocumented components, using scans, CAD modeling, and modern metrology tools.
This allows us to refine tolerances, improve longevity, and ensure future production models match the spirit and performance of the original.
Watch the Revival Unfold
Our YouTube series documents every step of the process - from historical overviews to behind-the-scenes footage of the re-engineering, machining, and early test fitting.
The Conley 427 - Specs & Highlights
- Scale: 1:4
- Configuration: 90deg. V8
- Fuel Type: Nitro blend
- RPM Range: Targeting up to 10,000 RPM
- Notable Features: Functional valvetrain, one-piece solid crankshaft, and optional supercharger
Behind the Build
This page will be updated frequently with:
- CAD progress and component reveals
- Machining videos and assembly previews
- Engineering insights and historical context
Follow along on YouTube and Instagram to stay connected.