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How does valve angle effect performance

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Old 08-06-2011, 02:45 PM
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Default How does valve angle effect performance

while looking at different sets of heads for my 6.0 I came across some that run different valve angles apposed to the stock ls1 degree given this I'm trying to understand how much improvment would say an 11 degree valve angle have over the standard 15 degree on a stock bottom end 6.0 considering either set had a cam to match.
Old 08-06-2011, 02:54 PM
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It helps straighten out the curve that the intake fuel/air charge has to make in the intake runner of the head to enter the combustion chamber. It there for has better flow and velosity. Which helps the engine produce more HP/TQ.
Old 08-06-2011, 03:46 PM
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So say a same casting heads with only the valve angle being different the lower angle one would make more power
Old 08-06-2011, 04:02 PM
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Originally Posted by slt200mph
It helps straighten out the curve that the intake fuel/air charge has to make in the intake runner of the head to enter the combustion chamber. It there for has better flow and velosity. Which helps the engine produce more HP/TQ.
Not sure I agree. I believe the angle is to cylinder bore so lower angle increases the short side radius and the flow turn. Nothing is free. You gain a little valve drop in the process but a 15 degree head like the AFR already has increased valve drop from stock heads. Here's some more information but I would do some searching and then contact some of the head guys like Tony at AFR to get better technical information: Link

Last edited by vettenuts; 08-06-2011 at 04:09 PM.
Old 08-08-2011, 12:02 AM
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The cathedral head is somewhat limited by the dimensions of where the IN.
runner begins...however a flatter valve angle has a floor that raises up,
twists, and drops the mix on the back of the valve..promoting swirl AND
tumble but not too much of either. Chamber inshrouding is also a given.
This usually only shows up in midlift flow #s and arguably mixture quality.
Remember we analize heads by airflow but the ports actually need to flow
an efficient mixture of air AND fuel.
Old 08-08-2011, 03:03 PM
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Thx for the info I think I have a good idea of the heads i want to run to have power where i want it probably between the TFS or mast. Mast or more but the TFS need roller rockers so they end up being the same but there are some others I am looking at not trying to start a head vs heads thread though.
Just looking for max midlift flow cam will probably be low .600 lift since neither a ls6 or fast can flow past a good set of heads at .600
Old 08-08-2011, 03:18 PM
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Im not sure on this and maybe someone can correct me if I am wrong. I think you can run bigger valves for a given cylinder bore as you go to less and less of an angle. I think with hipo and racing heads you get to the point where youre maxed on flow due to valve size. The next logical progression is to figure out how you can run bigger valves. Like I said I am not sure but I think this comes into play.

The angle of the valve gets into where the valve pockets are in the pistons, so watch out for this.
Old 08-08-2011, 04:08 PM
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Originally Posted by 95FbFormula
Thx for the info I think I have a good idea of the heads i want to run to have power where i want it probably between the TFS or mast. Mast or more but the TFS need roller rockers so they end up being the same but there are some others I am looking at not trying to start a head vs heads thread though.
Just looking for max midlift flow cam will probably be low .600 lift since neither a ls6 or fast can flow past a good set of heads at .600
I'm pretty sure that TEA offers a powdered metal valveguide for the TFS
cylinder heads which make them stock rocker compatible. You could have
either the 215 cnc'd version or the 220 as-cast but @ 13.5 deg valve angle
and not the 11 deg. Mast you also refered to..... Mast stuff is real nice BTW



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