Comp Cams Camshaft 35-426-8

blykins · #1 (**permalink**) 03-09-2013, 05:54 PM

Why such a big duration split? Hardly ever necessary at all.... Kinda counterproductive to have a longer LSA but such a large degree of overlap.

ERA Chas · #2 (**permalink**) 03-10-2013, 07:52 AM

Quote:

Originally Posted by blykins

Why such a big duration split? Hardly ever necessary at all.... Kinda counterproductive to have a longer LSA but such a large degree of overlap.

Possible the cam designer feels the AFR exhaust port needs help with greater duration? Especially with 'only' .560" lift??
That was the thinking (years ago) in my Ultradyne 244 / 255. And in my case that was right. The original iron MR exhaust was weak.

blykins · #3 (**permalink**) 03-10-2013, 08:57 AM

Did you try another cam?

The good sbf heads are not lacking on the exhaust side, unless you're making up for forced induction or nitrous.

I've never used more than an 8 deg split, even on drag race and road race FEs....that are supposed to be "exhaust compromised"...

What happens with a street engine is that you end up with a great deal of overlap.

I would rather match the lift to where the heads work the best then cut the split down to make it more streetable.