[firebirdcrazy1959]

I see alot of people saying my car poops out at 4500rpm,4,000 rpm,5,500rpm ect.Now when i say poops out i assume they mean no more power above that rpm.Knowing a cam has alot to do with rpm,how much does the head play into it?My car is a 80 Firebird,462-W/041 cam-ported #62's with alot of bowl work.t350 and 3.23 rear.The car would top out at 5,800 to 6,000 rpm.When i raced it,i knew if i hit a good light and just kept it mashed to the floor and shifted at 5,600 i would get a consistent time of 12.22at109.xxx So how much does the head play into the Max RPM?

[screamingchief]

So how much does the head play into the Max RPM?

The head itself,,,well,,,this statement is gonna raise some debate,,,none!

The heads flow may "crap out" and power will suffer,,,sure,,,but that does'nt really affect the ultimate RPM abillity of the engine,that mostly has to do with other "dyanmics" like the cam and valvetrain,and the lower end assembly.

This is'nt exactly an "optimum" situation,that is having the head flow fall off before the RPM limit is approached,but it still will perform none the less.

But if the valvetrain dynamics are off,and the RPMs surpass the limits of the valvetrains abillity to control such,power loss again is certain,also possble is serious engine damage.

NHRA/IHRA stock class cars use much higher RPM ranges than the average "street" performance combo does,and they do so effectively with more or less stock head castings (albeit with some very close attention payed to them) so consider that the heads themselves are'nt entirely the driving factor in these engines RPM range.

Bret.