"Burnt" spark plugs
#61
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forget the av gas...does NOT work well the specific gravity is way wrong for automotive/marine engines...will help some but not as much as expected...at this point would make no sense to me to try to run this compression ratio...short of changing the pistons the only head you can get away with would be the extra large chamber 71-72 454 365oval port or 425 rect port..if you can find them...and they are not a very good head either..but would get the compression down to a managable amount...
#63
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what should be the fuel preassure? the pistons are brand new, have only a few hours on the, break in basically. Im seriously considering changing the pistons. Im still waiting for the machine shop to get back to me, talked to them todday and they said the valves were perffect.
bore is 4.530 stroke 4.00
bore is 4.530 stroke 4.00
#66
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Fuel pressure should be at 6 or 7 psi . I am curious as to what heads you are running . Only because they sure look like closed chamber piston's and if they are open chamber heads compression is not the problem. After a closer look at the pic's I'm going to say you used the wrong head gasket's . Blocked off the water passage's to the heads , hens 220* and a dropped valve seat.
Last edited by Jeff P31; 01-06-2011 at 10:34 PM.
#67
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Fuel pressure should be at 6 or 7 psi . I am curious as to what heads you are running . Only because they sure look like closed chamber piston's and if they are open chamber heads compression is not the problem. After a closer look at the pic's I'm going to say you used the wrong head gasket's . Blocked off the water passage's to the heads , hens 220* and a dropped valve seat.
#68
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The exhaust valve seat droped and was pressed into the piston, then disintegrated mostly. The other head , the intake valve seat was also coming loose, hence the drop in compression. The machine shop said all the valves looked ok, nothing else was really wrong except the seats.
the heads are stock 502 heads, im trying to get the casting number to make sure.
Last edited by CafeRacerPTY; 01-07-2011 at 09:32 AM.