Quote:
Originally Posted by Batass  Are there any heads that will outperform swirl port heads under 4500 rpms? |
That's an unusual question here (counter to the usual SP head questions).
A small port aftermarket aluminum head might, like 180 cc AFR heads for sbc, but they're aluminum and $$$ so the mild gain at rpm below 4500 wouldn't be worth the cost. Ported swirl port would also (duh) be an improvement because they will flow better than stock while retaining the swirl and the fast burn that goes with it.
If you read Fast355 posts on the SP heads he has ported for his van and for his brother's 'burban, I think you'll find that he has had very good luck with them both below and above 4500 rpm.
I'll also add that a long time ago (a few years), Fast355 was a critic of SP heads because, like many people,
he had no real experience with them other than stock and running through a stock engine - - - so he would repeat the hearsay found in typical TBI TGO posts. Then he started porting them, and his opinion changed completely. So his experiences with them are more valuable because he once also thought they were junk. HTH.
