Is there going to be a BIG difference in the flow numbers at different lifts? If so how much of a difference?

 

very little if any difference, especially if stock chamber is being tested. I own a flow bench
BTW.

 

Thanks for the response. <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />

I had some '02 LS6 heads custom ported, and they followed very well from .400" to .600". The heads were flowed at 28" (whatever this means) Superflow bench at 58 degrees. He told me the bore size on his machine is 4.00" and not 3.90", so I was concerned the numbers might be abnormal by a big difference.

 

Teddy,
In the begining of my LS series head porting, I took some heat because I didn't have a 3.90 ID bore for testing, I tested anyway but in the meantime I had a local plasic company make me one for my Superflow from 4.00 to 3.90 and there was virtually no change. Possible 1-2 cfm, nothing to get upset about.
Joe

 

Joe Prince

2 follow up questions:

1. Would your answer be the same if a larger valved (2.08 I) head were flowed on both bore sizes?

2. How limiting is the LS6 intake manifold? Is some of the porting work not realized because the flow rates are diminished by the intake manifold?

For example, if at .500" lift the flow rate on the flow bench is 295 cfm, what would that really be with the intake in place? Would it drop to 260 cfm or would it still flow 295?

TIA

[ February 08, 2002: Message edited by: 2K1_4mula ]</p>

 

TIA
The 2.08 will be affected more than the smaller valve. on the Bore size change.
The Intake takes quite a told on the heads. about 40CFM. but there are somthings about the Intake that's not quite understood. The fact that you can turn 7500RPM and make power with it, states that it is alot more reliable than it should be. So maybe it's not as bad as the flow bench states.

 

The reason intake can lose so much flow over bare head, goes to show how much power motor can make without huge flow numbers. LS6 intake recoops alot of that loss.

 

LS1deer it will still make more power however with more flow. every time you add flow #s the car picks up power.( offcorse this must be done smartley)

[ February 09, 2002: Message edited by: One Monkey ]

[ February 10, 2002: Message edited by: One Monkey ]</p>

 

hUH?