I know that a single pattern cam requires better flowing heads on the exhaust side, my question is why? And if u do have a good set of heads, why would a single pattern cam be advantagous?

 

Dual pattern cams were designed to be used with stock or stock replacement heads along with more restrictive exhaust systems to help offset the restrictions.

When using an aftermarket head (like AFR, Edelbrock RPM's, etc.), of course they'll flow better than a stock head on the exhaust side, plus the exhaust system will more than likely be upgraded as well. Because of this, a dual pattern cam may not be needed.

I can't say what kind of negative effects it would have using a dual pattern cam in that situation though. I don't have any direct experience with good aftermarket heads.

WAG - It will overscavenge the cylinders.

 

Tuned ports love single pattern cams when you have nice heads

 

Whats WAG?

 

Wild A-s-s Guess

 

TPI? or Tuned Ports?

It would depend on how the port is tuned

The TPI still needs dual pattern to offset the restrictive TPI...

 

TPI is tuned port.

Tuned Port Injection

 

TPI is Tuned Port INjection...but change tyhe runner length and cross section...and youchange the tune...and subsequent camshaft choice.

 

Good question... Meaning, I don't know the answer, but I wish I did.
Something to consider tho, is TPISs cam selection.
They've got the ZZ9 cam 212*/226* @.050
then they've got the Super L98 226*/ 226*.
Both are good, and both are designed to be used with TPI or Miniram, AFR heads, and headers.
With the ZZ9 you couldn't find a more extreme example of a dual pattern cam with 14* difference in duration between In and Ex, Yet it supposedly works with the same combo that the larger single pattern cam works with.



does that help at all?

 

Check out “Tech Tips 2000” from the link below. “2003 and 2004” has information related to your question.

http://www.iskycams.com/techinfo_index.html

 

Not necessarily true. Look at the LS1 engine. Those guys had a big thing going a couple months back w/ reverse split cams, b/c their exhaust was so good, and the exhaust flow on the heads is so good, but the intake is their restriction on H/C cars.

The same thing could be said for TPI cars. Since the intake is such a restriction, you don't need as much exhaust duration to get rid of exhaust gases, b/c the intake is the major restriction.