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Discussion Starter #1
Quick question...I was taught to buy anew gasket and place it on the intake and exhausts chambers of the head.Then take a marker or something of the like and make an outline of the inner gasket. Now, if I were to do this, what kind of gasket should I use? Example, a gasket from Autozone or is there some kind of gasket made specially for this application? And the second part is... that's considered a mild port/standard porting job. What else needs to be done to be a "wild" or "extreme" porting job? Take out alil more of the chambers? Wouldn't that be making the head alittle weak?

Now for my third. What would happen, (for sh*ts and giggles) if I were to port the exhaust side alittle more than the intake side? Or vis versa? And how much of a port is to much, what is the limit. Thanks
 

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this would be used for a turbo setup by the way, anywhere from 7psi to 13psi. Pretty much a complete build of the engine, new pistons and rods, etc..
 

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Portmatching (which is what's done with the gaskets), cleaning up the casting marks, and deburring the combustion chamber is all that should be done to a forced induction head with mild pressures.

No special gasket needs to be used to portmatch.

Cleaning up the casting marks is when you use a tool to remove the ridges and bumps in the runners left by the casting process when it was made.

Deburring the combustion chamber is where you remove any sharp little edges in the combustion chamber area that may glow red hot and cause detonation. Don't mess with the valve seating area, obviously.

'Wild' head work will provide very little gains with 7-13PSI, and should not be attempted by amateurs. Hogging out runners will decrease velocity, and will seriously hurt fuel atomization. Often times DIY (Wild) headwork will decrease performance.

Take your time, and portmatch the head to the intake and exhaust flanges. Gently remove any casting marks in the head, IM, and exhaust. Deburr the combustion chamber of any potential hotspots, and you'll be good to go.

-Des!
 

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taking too much off would be a port that is bigger then the gasket.

also if you ported the exhaust side a significant amount more then the intake you would probable get increased back pressure.

if you ported the intake side a significant amount more then the exhaust you are gonna decrease air velocity and allow the atomized fuel to start sticking to the walls. other than decrease velocity and hurt fuel atomization i don't think it would effect anything else. besides the stock intake size is bigger then the exhaust side because the exhaust flows better already. hence the reason why the exhaust valves are smaller than the intake valves
 

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.

i have two questions.

did the person that created the gasket know the ideal cross section of the port at that given point?

no matter how big or small your port is, what is the limiting factor in flow?


m.
 

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i guess the limiting factor in flow would be velocity and turbulence... could be wrong tho
 

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Discussion Starter #8
I've ported and polished an engine before, so I am familiar on how to do it. I was just at work last night thinking about the head and how much flow is capable to get inside the head. They were just more or less, needless to know questions. Except for the first part of my question on special gaskets.

Why would a p/p job do little gains? Your meaning someone who doesn't know how to do it screwing it up and killing flows into the head? What gains would be achieved, if I did know what I am doing? Or is it even worth while to do a p/p job at all?
 

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Gasket matching is wanna the best ways to unlock hidden power. It will aid in making power from bolt on. Better the head flows the more the power gain from headers, intake exhaust...blah blah blah. Dont slick the intake side smooth, you can mirror finish the exhaust though. Good luck though...
 
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