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Airflow question?


Cordell

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First off don't answer this question telling me to just go somewhere and take what they sell me because I'm not going to. I am going to plan, build, and tune this combo, no one else.

 

I understand how an engine's components have to be matched to each other, but can you have too much airflow through your cylinder heads? I'll have as much airflow as anyone is going to get through a LS1 style intake manifold without buying the 92mm TB, a healthy cam, and plenty of flow through the exhaust. My original thought was to get as much flow as I could in the heads given the bore size. Would there be disadvantages to this, and what would they be?

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wow...

 

alot is going to depend on intended use. ie like spray motors need more exhaust flow then say a n/a motor.but having max flow is not also good, cause this can hurt mid range power, and a major power loss down low. most head porters look for average flow gains across the lift spectrum. and to be honest man, it would take hours of explaining this.

 

what are you trying to do? pm me if need be.

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Scott,

 

Porting too much can be very detrimental to flow numbers.. If you're staying N/A I would suggest port matching and just sanding all the burrs out of the casting. Porting is something you REALLY need to understand to see benefit.

 

I see it happen all the time, especially on the large-port 4AG heads, where even performance shops are making changes to heads that only hurts flow and causes poor atomization before it gets to the cylinders for combustion. I get the idea that you're much like me, and really don't like other people doing the work I feel I could do myself, but this is something I would just leave to someone who has a lot of experience and can properly bench flow test your heads.

 

Take Rob's advice, he's spot on.

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I will be buying some off the self CNCd cylinder heads and just don't want to get carried away. I'm not going to be doing any porting of my own, just some clean-up on the intake and such. While I would like to know more about true custom componets fabricated myself, my build will be properly installed and tuned off the shelf parts. I think that what I'm looking at will be border line too much, but I grow into it. I'll take this to PMs with a few of you if need be, but any other input would be appriciated.
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scott, stage 3 ported heads are the max i would do, that still maybe more than your stock cubes can pull through though. for your set up though i think the stage 2 IPS heads would fit the bill nicely. match that up with a LS6 intake if you can (or port your LS1) and you should have a decent flowing setup and good port velocity to get the max air into the cylinders and make good power across the board. mine are stage 2, i think i still have the flow chart for them if you want to see it.
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scott, stage 3 ported heads are the max i would do, that still maybe more than your stock cubes can pull through though. for your set up though i think the stage 2 IPS heads would fit the bill nicely. match that up with a LS6 intake if you can (or port your LS1) and you should have a decent flowing setup and good port velocity to get the max air into the cylinders and make good power across the board. mine are stage 2, i think i still have the flow chart for them if you want to see it.

 

I take it you are refering to IPS's heads? Yes please post the flow chart.

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please do!

 

what bore was used to the flowing of these heads? test pipe on the exhaust side?

 

 

wonder how they would handle being flowed with different intakes and throttle bodys to get true air flow?

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One of the things that comes to mind for example is how well the L92 heads flow from the factory and those came on a truck. Same heads they put on the LS3. I suppose I want a physics lesson on airflow, so......
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someone out there has had to have done airflow research work with these im sure.

i remember reading about the head flow with a carbed intake some where in hotrod if i remember right.

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not sure how they flow them. the IPS heads flow slightly more since they are machined to there specs.

stage 2

http://www.livernoismotorsports.com/prod_imgs/img-1351-large2.jpg

stage 3

http://www.livernoismotorsports.com/prod_imgs/img-1352-large2.jpg

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see they only really gain around the .400 lift mark which is about right.

and see at the bottom they only post the max lift flow with the test pipe. and im sure those are not with the intake and TB in place.

good numbers. but im wondering about what they flow with different intakes and carb/TB in place.

and yet alot is still left up to the cam on how that airflow is used

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The heads I am looking at are very similar to those stage 3s. I'm not going to talk specifics of my new combo online, but I'll just have to find out if it'll work well. If it doesn't I'll just have to make more improvements, but I think everything I'm changing will work well together. I'm getting very excited, and I'm sure when I see some of you out I'll actually tell the truth, but until then...........
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if you go anything over stage 3 then you starting hurting youself. stage 3R will out flow stock cubes and hurt you since you loose velocity.

 

Well since I'm not stock cubes :ninja:, I guess velocity is key. Hence why AFR's heads are so popular, bigger flow on smaller ports. I should be fine.

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