General Hemi Info Part 5


The builds:

Well, since I covered finding the parts required to put an early Hemi together, I figured I’d go ahead and talk about actually building one or two.

I’m be covering the 2 early Hemi’s I’m building, a 354 for the 57 Plymouth and a 331 for the 37 Dodge pickup.


The 354 has been bored .060 (which happens to be the same size as a standard bore 392 Hemi). Using stock 392 pistons yields a 10:1 compression ratio which with the Hemi heads is still streetable on pump gasoline. Displacement on the 354 is now at 365 cubic inches. The cam is a .450 lift/290 duration which is actually a reasonably stout grind for an early Hemi street motor.

The 331 is also bored .060 over and now displaces 341 cubic inches. It is receiving a set of aftermarket pistons and with the milling on the heads and block will be running a 9.5:1 compression ratio. The cam choice is a bit milder at .440 lift/280 duration. I chose this cam due to the smaller displacement and the plan to run an automatic and relatively high gears behind the engine instead of a 4 speed like the 354 will be getting.

The 354 will be getting cast iron manifolds (which actually flow very well) and at this time it’s up in the air whether the 331 will be getting manifolds or headers.

Both of these engines are build as basic street motors, nothing fancy or “race only”. They will both require premium fuel, but intended to be driven long distances and have a lot of miles put on them.