Another Idea....no one will like this but...

[mustanghammer]

.600 valve lift in STU….….WOW, really? "Stock" blocks and bottom end parts are required.....no way....really? I think I have seen this before....

I had not paid attention to the allowances for piston engines because I don’t plan on racing one. But seeing this allowance and reading allot of the justifications for JDM/Euro spec engines I think I have an easier solution. Drop the valve lift specs and detune the engines. Here is why:

When American Sedan was introduced in the 90’s the engine specs called for all OE engine parts. Stock blocks, cranks, rods, etc all from the car’s years of manufacture. Carburetion allowances were set at 600CFM (Holley List# 4776), the intake manifold was a high RPM dual plane that could be ported and cam lifts were set at .500 for Fords and .480 for Chevys. The Ford guys got some so-so OE heads and the Chevy guys were set to use the stock heads because they flow better than any OE Ford heads (or so everyone thought). On the surface this seemed like a recipe for a 275-300HP engine. So the OE bottom end stuff should be fine…..right?

WRONG! Engine builders were able to generate well over 400HP for the Ford and a little less for the Chevy. Allot of money, tricky machine work and HIGH RPM numbers (like around 8000) are required to get there. Now try to make an engine that produces this kind of power, that is being spun this tight and using American Made OE parts survive a National race. It was a disaster and is the reason why American Sedan engines are now based on aftermarket racing blocks, aftermarket forged cranks and aftermarket forged rods.

At some point the A Sedan community had the choice to move forward and slowly integrate race/aftermarket engine parts in to the class or take off that monster carb and put on a lower RPM manifolds. They took the former approach. In my opinion they screwed up and you can see the results on the grid.

[Chip42]

well, the good news is that a lot of the motors that fit this class (even in an all US market sample) are known to be able to make 2-3x their factory numbers on stock bottoms, and spin to 8-10k in the process, on the street, reliably.

but yeah - you potentially have a VERY good point. It might help to keep the class modern by evolving out the older stuff. thank you, Casandra.