Originally Posted by fast68plymouth
Originally Posted by BradH
Hypothetical scenario:

Take all the top end parts of a 680 HP / 600 torque 3.75-stroke combination with standard Victor heads.

Put them on a 500"-ish short block and keep the CR in pump gas territory... probably bump up the cam for the extra cubes.

What's the likely end result?

EDIT: I'm very happy with the my 3.75-stroke combination and it's a really good match for my car. I'm describing mine because it's a better example of what I was trying to ask than I think how most people understood my question.


From what I’ve seen, when the heads are kinda “too small”....... adding cubes and lowering the CR really takes it’s toll on the upper rpm of the power curve.
Even if the bigger motor makes considerably more tq, if it can’t carry it high enough....... you could end up not making much addition hp at all, and could also end up with a noticeably shorter usable power band.

With that type of build, the overall car/motor/converter combo needs to really be able to exploit the added tq at the beginning of the power band.

I fired up Pipemax 3.9.8 this afternoon for the first time in a couple of years to see what it indicated. I only tried a few long-stroke scenarios per my description above. It "thinks" there would be a significant power improvement, but also predicts a bigger cam won't make any additional HP and loses peak torque. Head CSA requirement calcs point to the Victors as being smaller than optimum for best combination of HP and torque, but OK with the emphasis on torque.

Regardless, it's not looking like a great approach; no big surprise...


Last edited by BradH; 11/24/19 03:36 PM.