Goodwin Competition Billet Aluminum Semi Hemi Engine - Engine Builder Magazine
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Engine of the Week

Goodwin Competition Billet Aluminum Semi Hemi Engine

Todd Goodwin of Goodwin Competition, Inc. has seen championship success after developing his own billet aluminum performance engine. Named the Semi Hemi, it is more than capable in drag racing, truck pulling and even marine applications. Oh, and did we mention its one of the highest horsepower pump gas engines in existence.


In a small, two-stall garage 32 years ago, Goodwin Competition, Inc. was started by owner Todd Goodwin.

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The shop is very diverse according to Goodwin who says they work on dirt, late-model, sprint car, offshore marine, drag racing, and circle track engines. This diversity ultimately led Goodwin to design his own engine suitable for many of these applications.

For two and a half years Goodwin designed, prototyped, manufactured, tested and perfected the Goodwin Competition Billet Aluminum Semi Hemi engine.


Goodwin did all of the R&D work on it, and since the shop has its own Spintron he was able to run dynamic tests, which made it a more exciting project.

Boasting a custom 70mm Howard’s or COMP cam with 10 roller cam bearings in an enclosed cam tunnel and 1.062″ diameter keyway lifters and a best in the industry valvetrain, it’s no wonder this engine earns high praise from those who race with it.

“We make the engine completely out of billet aluminum,” Goodwin says. “The blocks, heads, and most of the accessories are made out of billet aluminum so it’s kind of exciting to build something a little bit different than what everybody else is doing.”


Goodwin’s desire to do his own thing has followed him since his high school days.

“When I was in high school, I was always trying to make everything faster,” he says. “Everything I found I would try to take apart and make it better.”


The shop machined all the aluminum parts for the Semi Hemi themselves, except for the steel billet crankshaft, which Goodwin said he gets from either Bryant Custom Crankshafts or from Callies Performance Products.

These engines from Goodwin Competition all have 5.000˝ bore spacing – but from there, they have very different characteristics. On the left is a 650 cubic inch Semi Hemi NTPA Grand National Truck pulling engine, 1648 horsepower. Also available with Fuel Injection. On the right, a Semi Hemi 762 – 780, 800, 815 , 1700HP to 1820HP. In the middle in back: 650 cubic inch Semi Hemi, Twin Supercharged Marine Engine, 1940 horsepower on 93 Octane pump gas with Goodwin/AEM engine management system with Engine guardian and full Data Logging. And up front in the middle: 715 and 730 cubic inch Semi Hemi Drag racing, 1775 – 1815 horsepower.

Goodwin says this engine has quickly become one of his favorite ones to build because of his own design.

“Since we make everything out of solid billet instead of a casting, I have the creativity to do whatever I want because we machine everything out of a solid chunk of aluminum,” he says.


The engine is pretty diverse in itself and with a few modifications it can be used for applications like drag racing, truck pulling and even Offshore Power boats with V hulls and Catamarans (Skater’s). Horsepower on the 650 cubic inch truck pulling engine runs right around 1,625 – 1645 with 1,100 ft.-lbs. of torque.

“In offshore marine engines, we put two superchargers on them and that’s been a pretty big hit,” says Goodwin. “You put two of these in a boat and they’ll go well over 200 mph. So people use them because it’s the highest horsepower pump gas engine anywhere right now in existence.”


Goodwin says he’s constantly refining the engine and after each race when his customers come back he’ll always look for improvements that can be made.

“We’ve won several championships with them so it’s been a really great piece,” says Goodwin. “In fact, the first time we manufactured the engine for a customer, it went out and won a championship in the NTPA four-wheel drive modified class.”

The engine also uses Jesel or WW Engineering rockers and Jesel belt drives.

“Aesthetically the engines are mind blowing because we do everything using 5-axis simultaneous machining; everything is all 3D contoured,” says Goodwin. “So it looks as good as it runs.”


Goodwin Competition builds and ships engines all over the world in addition to designing and CNC-porting cylinder head packages for other engine builders. Currently the shop is working on three new billet V8, V10 and V12 engines.

Engine of the Week is sponsored by Cometic Gasket

To see one of your engines highlighted in this special feature and newsletter, please email Engine Builder managing editor, Greg Jones at [email protected]

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