Will these fit the SO 302? I know they say they wont fit the '86 HO with out valve reliefs, but the so does have slight dishes in the piston. guess the only way to find out is bolt em up and check.:hick:
there's a good possibility there will be some contact, even with the small dish.. nothing a little clay won't help to figure out
Bolt
Sensible and logical. Thanks for the tip, Tom.
That's what I'd do WLD BRD.
If they hit I believe Zonda made a tool to cut notches in the pistons when he added iron GT40s to his SO engine.
Was just gonna say they're most likely gonna hit RJ. :hick: Needed VERY light cutting into the pistons to make the needed clearance actually work. But of course that looked to me like it could nevvvvver work
It's real easy to take care of though...a little bit of a workout and more annoying for a weakling like me because of setting the heads on and off several times LOL. But I went and got a basic chevy 350 valve or something, just made sure the size was slightly bigger than the GT40 valve sizes, and get a package of adhesive backing circular pieces of sandpaper for a DA sander or whatever, and cut small circles out of that. Cut them a little bigger than the face of the valve itself so it wraps around the edge of the valve once you stick it on. That way the cut into the piston will have slightly chamfered (rounded) edges and won't contribute toward making hot spots and causing pre-ignition.
Tape off the ENTIRE deck surface, poke a small hole in the tape in each cylinder as far away from where the valves would hit as possible. This way when you crank the engine, it won't suck in or push off the tape. And, any metal shavings won't get past the tape. You set the head down, with the valve in it's guide, piston at TDC naturally, and grab the stem with a drill chuck. You might not think so (I didn't) but sandpaper glued to a valve digs into an aluminum piston pretty quick!!! So don't bear down hard on it, have 16 cut out, one for each valve, but I did get away with using one or two for two valves before the wrapped-around part of the sandpaper wore off. But the actual cutting is real quick. Take a marker and mark on the stem how far it needs to go down, that way there's no guesswork. Have a good vacuum cleaner to suck from the intake and exhaust ports, use the spark plug hole as well, rig something up seal it with tape or something, have it running WHILE you're using the drill to cut. I vacuumed out each cylinder afterward to be safe, but doing this you should have no metal left behind.
i saw this trick on horsepower.. they did it to a SBC but it's the same process and super easy.. never done it myself because i always change the pistons, but it seems to work out pretty good
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going with either a E cam. or more likely a Trick flow stage 1, but after thinking, there really is no point in doing this work on the SO because the pistons arent forged and I will be adding a blower in the spring, or over the winter. may just do a stock HO conversion for now. then build a dedicated blower motor.
thanks for all the tips guys.
I was kinda wondering why you were going to stick a blower on a cast piston engine ;).
thats ok, my engine was thinking I was trying to make it a suicide bomber LOL.