Head Work
AdvanTech
01-23-2004, 12:14 PM
There are many things to consider when building a high performance head:
Myth: A head with higher flow bench numbers will perform better than a head with lower flow bench numbers.
Reality:This is not always the case. If you make a port big enough to make big numbers on the flow bench, you might not realise that you are slowing down the speed of the air travelling through. So the best setup would be make the ports big enough without sacrificing too much port velocity.
Nitrous engines like big exhaust ports, but imagine how your engine would run when youre not using it.
If you make a port really big on a turbo engine, it creates more turbo lag, and creates idle and driveability problems on street cars.
Also, when port-matching an intake manifold to the head, make the entrance of the intake a bit smaller than the head. This will help with reversion during overlap, especially with cars that run nitrous.
Do not put a bgger valve on your head unless you are going to port the bowl to the same size as the valve. And sometimes with too large of a vlave, you can hurt flow because the cylinder bore will shroud the valve.
And also think about what cams you will be using because the intake and exhaust valve might touch each other during overlap.
Thats all I have, so please add on if I missed something, or did not explain well enough. :smile:
Myth: A head with higher flow bench numbers will perform better than a head with lower flow bench numbers.
Reality:This is not always the case. If you make a port big enough to make big numbers on the flow bench, you might not realise that you are slowing down the speed of the air travelling through. So the best setup would be make the ports big enough without sacrificing too much port velocity.
Nitrous engines like big exhaust ports, but imagine how your engine would run when youre not using it.
If you make a port really big on a turbo engine, it creates more turbo lag, and creates idle and driveability problems on street cars.
Also, when port-matching an intake manifold to the head, make the entrance of the intake a bit smaller than the head. This will help with reversion during overlap, especially with cars that run nitrous.
Do not put a bgger valve on your head unless you are going to port the bowl to the same size as the valve. And sometimes with too large of a vlave, you can hurt flow because the cylinder bore will shroud the valve.
And also think about what cams you will be using because the intake and exhaust valve might touch each other during overlap.
Thats all I have, so please add on if I missed something, or did not explain well enough. :smile:
GsR_95
04-06-2004, 06:15 PM
Yea I Have Crowers Drag Cams And I Have To Build My Head. Im Doin A 3 Angle Vavle Job, Port Polish, Upgrade Ecu, And Shoot Nitrous Later On. Im Paying About 1500 For The Job, Wat Do U Think?????
AdvanTech
04-06-2004, 06:32 PM
Yea I Have Crowers Drag Cams And I Have To Build My Head. Im Doin A 3 Angle Vavle Job, Port Polish, Upgrade Ecu, And Shoot Nitrous Later On. Im Paying About 1500 For The Job, Wat Do U Think?????
lol It's been awhile since I made this post :)
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lol It's been awhile since I made this post :)
PM sent
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