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Port polish your own heads?
Anybody here ever port/polish thier own heads? I was reading that with a little practice and a kit it is supposed to be easy.
Also, 305 heads on a 350, anybody do that? I know where I can get a free set. |
It helps to get an old head and practice first.I did aset and all I did was smooth the walls up didn't want to f#$@@ up my new heads so I was real cautious.It is easy but time consuming & you need a big air compressor.What are the #'s on your heads? As far as putting them on they are a direct bolt on.
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Don't know, I don't have them yet, I'll have to check. I'm looking for mild performance and decent gas mileage. Will it affect which headers I buy if I run the 305's?
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this is a pretty good info.
http://www.sa-motorsports.com/diyport.htm Best to just gasket match for the street and do bowl work (area under the valves) You will need to make sizing valves to use as templates. You mainly want to improve velocity. Have done Pontiac heads see pics. http://www.freephoto-i.net/users/Fra...t_port_ftz.jpg http://www.freephoto-i.net/users/Fra...ber-far-LR.jpg http://www.freephoto-i.net/users/Fra...rt_ftz_far.jpg |
I ported and polished my own, it is very very time comsumming, but it is worth it, with a good set of heads, just remember if you put a hole in cast iron, it is pretty much history, alum is fixable
sam |
Thanks guys. Frank, that's the site I was reading on. Did you follow his plan?
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Good place to start.....to do any serious porting you need a carbide cutter and sizing valves. You want the throat to be a certain diameter. For a street Pontiac with 2.11 intake valves you use a 1.66-inch valve for sizing the bowl and throat. You insert the valve and keep slowly grinding away until it falls into the bowl all the way to the roof and part way into the throat. The next area is the sort turn radius. Then there is the side walls next to the sort turn radius….you widen and smooth. You don’t polish you want a ruff finish to help improve fuel are mixing on the intake. You do however polish and smooth the combustion chamber and the exhaust ports. On the exhaust side you widen the throat at the sort turn radius and smooth the short turn radius. Try to visualize a smooth flowing waterfall.
The main idea is to try to visualize the areas of restriction and open them up. |
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