Dropped a valve!!!!!!!
05-14-2015, 06:51 PM
#11
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The nice thing about moving to a 4.500 bore, is the chamber can be modified easily to accomodate the larger bore, if it needs to be opened up.
You really dont want a head with a chamber for a 4.250 bore, on a 4.600 bore, and you def dont want a chamber for a 4.600 bore on a 4.250 bore block.
Bolt the head on the bare block, turn it upside down and take a look.
the camshaft will also dictate the rpm the engine will make its peak power, at least on an average 6000 RPM or less marine big block chevy.
You really dont want a head with a chamber for a 4.250 bore, on a 4.600 bore, and you def dont want a chamber for a 4.600 bore on a 4.250 bore block.
Bolt the head on the bare block, turn it upside down and take a look.
the camshaft will also dictate the rpm the engine will make its peak power, at least on an average 6000 RPM or less marine big block chevy.
05-15-2015, 07:29 AM
#14
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I think Im going to do the 540, I can always change the heads later without pulling the engine from the boat. You know what they say, no replacement for displacement!!!!!
05-15-2015, 07:33 AM
#15
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without knowing the output of the 489 we will never have any facts to support how much more power the 540 will make but it WILL make more power with the right camshaft.if you have dart 345 heads,use them as they will produce more power than the iron 320s.
