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Porting Heads. Suggestions Welcome

bbptech

bbptech

New member
Alright guys so i have a set of stock heads from my L67 that ive had since i put ported heads on from ZZP. My plan is to disassemble them and port them for a turbo build later on in the future.

What are some suggestions u guys can give me that i can reflect on these heads? Things i need to look out for? Things i should and shouldnt do?

I know not to open up the exhaust ports to a circle. What are things to look out for while blending and smoothing the combustion bowls?

Will have progress pics as i go. So keep an eye out for them.

Thanks,
Colin
 


have a machine shop magneflux the heads to check for cracks around the exhaust valves. dissassemble, then get some gaskets and port match them( time and sand drum rolls are your friend).. also. keep exhaust in original shape or u'll f it up. (i once did). with valves removed there is plentu u can do, removing sharp edges. it's really better to do too little than too much. read alot and look up alot about porting on the net. this is what i'll start doing my self next month. spend some bucks on some gvarious shaped carbide bits and drum rolls.
 
i would say first of all, gm made the heads the way they did for a reason (all the curves and bends) and after doing some research those bends and curves are there for a reason (helps volicity) so i would not strait line anything. smooth out the curves, and if there is any unnessecry humps, you can smooth those out also.

i started on a set but have not touched them in a while. what i do is take a little flash light and shine it thru one end and look at all the showdows and what not, kind of gives you and idea of the little humps that could probably be smoothed out.

in this case, less is probably more. port to much and you **** up the flow dynamics of the head. my advice, go real slow, on a slow speed seating drimel, and just compare to the stock port. you basically just wanna smooth things out while maintaining the same shape.
 
Porting heads is dumb and results you in no gains. If you want power, turbo it. I would smooth out the runners, polish the exhaust runners and polish the combustion chamber. The only reason to actually port heads is if you are doing an all out drag car in which you are going WOT and nothing else. If you mess with the port design at all, you are decreasing VE which will benefit you when you are not WOT and just cruising.
 
im doing these heads for a turbo build later on in the future. Plus im doing it because i wanna learn. I have a few pics of where im at right now. Of course im not done yet but here they are.

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minichopper6hp said:
Porting heads is dumb and results you in no gains. If you want power, turbo it. I would smooth out the runners, polish the exhaust runners and polish the combustion chamber. The only reason to actually port heads is if you are doing an all out drag car in which you are going WOT and nothing else. If you mess with the port design at all, you are decreasing VE which will benefit you when you are not WOT and just cruising.
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LMFAO.

Your a riot. Porting the heads on ANYTHING will net you more power. Especially on boosted cars. If your ported heads aren't gaining you any power...then your doing something wrong.
 
The key is not to have them hogged out too much else you will lose velocity and power.

But with forced induction and a big cam, that really isn't an issue.
 
how can porting heads be dumb when they are ported correctly? i bet with JUST heads on the car you could run a 3.2 pulley with a conservative tune.
 
matt5112 said:
The key is not to have them hogged out too much else you will lose velocity and power.

But with forced induction and a big cam, that really isn't an issue.
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Ya definetly not hogging them out. Just smoothing and blending is all im doing. Ive seen pictures of the heads some guy did over on clubgp that hogged out the exhaust ports. haha.
 


Bio248 said:
how can porting heads be dumb when they are ported correctly? i bet with JUST heads on the car you could run a 3.2 pulley with a conservative tune.
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Agreed noob. I bet with injectors and headers you could get away with even smaller if your still on a GenIII.

bbptech said:
Ya definetly not hogging them out. Just smoothing and blending is all im doing. Ive seen pictures of the heads some guy did over on clubgp that hogged out the exhaust ports. haha.
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Yeah some guy did that here too.

The key is to open them up as much as possible while still keeping the "square-ish" shape. As for the intake side...a lot of Aussie guys seem to think the smoother the better as fuel injection makes a difference and atomization on the intake doesn't matter anymore. I still disagree there...but then again...those guys down under are crazy:th_nanana:
 
Alright thank u for all the suggestions guys. Does anybody have some pictures maybe of the work they have done themselves?
 
I'd talk to Dave (trannyman)...he might be able to point you in the right direction. I've got some ported heads but they are still at the shop with my block 60 miles away :(
 


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