Head porting...
- Jordan
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Head porting...
I'd at the very least like to do some gasket matching on the intake side, and maybe do some basic port/smoothing/chamber balancing. Does anybody have any good references they have used, or recommended products. Even words of advice would suffice . Just something to keep the automotive projects moving during the winter months.
when i ported mine, i just aimed to get it really really close at the gasket mating surfaces. i did both intake manifold and intake side of head using an 'egg' shaped carbide bit. on the runners,
my goal was to smooth everything out. i should have popped out my valves and ground the seats flat, but i wanted my car back on the road a day sooner than it would have been otherwise.
the real work comes when you start using paper. start with 120 grit wet/dry going around, then 220 in and out, 320 around, 400, 600, 800 should be plenty and will surely keep you busy... you want to alternate direction, just sand until you can no longer see marks across the direction you are currently working. once you get past 220, the rest goes pretty quick. it is the initial smoothing that takes forever. there is a lot of material removed when working with 120 and 220
my goal was to smooth everything out. i should have popped out my valves and ground the seats flat, but i wanted my car back on the road a day sooner than it would have been otherwise.
the real work comes when you start using paper. start with 120 grit wet/dry going around, then 220 in and out, 320 around, 400, 600, 800 should be plenty and will surely keep you busy... you want to alternate direction, just sand until you can no longer see marks across the direction you are currently working. once you get past 220, the rest goes pretty quick. it is the initial smoothing that takes forever. there is a lot of material removed when working with 120 and 220
- Geoff
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Some people port and polish to get a faster/smoother air flow (you end up with more laminar flow). Some people leave the rough casting and just port match the surfaces. This gets you more turbulent flow and helps mix the fuel and air better. I don't really know what is better but I've never polished my heads because its work and the work may not be beneficial so I don't bother
The kind of dirty that doesn't wash off
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there was an alfa specific book and a chevy small block specific book that both talked about volume/velocity of gas through the chamber. Take a look through Barnes and Noble for various "speed secrets" books and see what you can find.
A lot of improvements can be made by softening the bend from the intake runner portion to the bowl underneath the valve head.
A lot of improvements can be made by softening the bend from the intake runner portion to the bowl underneath the valve head.
- SaabsBreakDown
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Haha. I said almost exactly the same thing on saablink the other day. I guess he is just pissed he spent all that time sanding and wants to make everyone else suffer too.Luke wrote:I think polishing past 220 grit would be a major waste of time.
Also: http://en.wikipedia.org/wiki/Cylinder_head_porting
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