502 upgrade, anyone got a good setup?
10-29-2010, 09:49 AM
#21
Registered
You are trying to reach a pretty easy goal. What you are asking is not very difficult to accomplish. There really is no reason to have some super special top secret cam to make less than 1.15 hp/ci. from a BB Chev.
I also would not normally recommend spending a bunch of money porting stock heads, but in your case I would go ahead and do the chambers. I would also deck them some to bump the compression. Porting the chambers will help to remove potential hotspots that may occur with the bump in compression and increased cylinder pressures. The stock heads have a pretty sharp edge that is left when the heads are cut for the valve seats. There is also a hump right near the spark plug that is also a potential hot spot. You may also consider just a little work in the bowls. There is also a pretty good sized hump just below the seats. Porting both the chambers and the bowls should only run 400-500 per set at most.
With the combustion chamber porting, a bump in compression, a decent camshaft, good intake (Dart, Brodix, or similar single plane), you should easily be able to make your target power of 575.
Let me know if I can help in any way. Thanks
Eddie
I also would not normally recommend spending a bunch of money porting stock heads, but in your case I would go ahead and do the chambers. I would also deck them some to bump the compression. Porting the chambers will help to remove potential hotspots that may occur with the bump in compression and increased cylinder pressures. The stock heads have a pretty sharp edge that is left when the heads are cut for the valve seats. There is also a hump right near the spark plug that is also a potential hot spot. You may also consider just a little work in the bowls. There is also a pretty good sized hump just below the seats. Porting both the chambers and the bowls should only run 400-500 per set at most.
With the combustion chamber porting, a bump in compression, a decent camshaft, good intake (Dart, Brodix, or similar single plane), you should easily be able to make your target power of 575.
Let me know if I can help in any way. Thanks
Eddie
10-29-2010, 10:07 AM
#22
I agree. Cam doesn't need to be top secret. But.... when I discussed the way I used my boat with rmbuilder, and what I had in mind for rotating assembly and induction, and what I expected from the engine (NA 557), Bob Madara came up with a grind to suit my needs. On the dyno the engine was within 100 RPM of the range we were looking for. It's run flawlessly for 3 seasons and I couldn't be more pleased with the results.
Last edited by Kidnova; 10-29-2010 at 10:13 AM.
10-29-2010, 11:09 AM
#23
Registered
Eddie is right on about the cast iron GM heads. I have ported and polished a few sets (for my own use). The set I have now are large oval 820's and I cleaned mine up just as Eddie described. If you are a "gear head" or do it yourself kind of guy all you need is a good air compressor, rotory tool and standard abbrasives kit. Or you could send them to Eddie and let him do it for you.
I am however completly sold on the RMbuilder cams. I gained 5MPH going from a so called performance flat tappet cam.
I am however completly sold on the RMbuilder cams. I gained 5MPH going from a so called performance flat tappet cam.
