455 rebuild advice needed
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Joined: Nov 2012
Posts: 18
455 rebuild advice needed
I plan to rebuild a 455 on a fairly tight budget over this winter that i'll be putting in a 72 Firebird with an uprated TH350 box and 2.56posi axle (might replace that with a 3.08 posi)
I have got hold of two 455 engines that i've stripped down and plan to make one good one out of the two.
The first is a tired 1975 engine with J heads that had never been apart before.
The second is a 1972 engine with Ga heads and nodular crank that has fairly recently been apart and rebuilt with +30 thou pistons but has had stitch repairs done to repair frost damage to the block.Head gaskets were leaking on this engine and block looks a bit suspect !
My plan is to have the 1975 block bored +30thou and put the nodular crank,rods and almost new pistons from the 1972 engine into it with new rings and bearings.Topped off with the Ga heads (egr/air bumps ground down,new valve guides etc)factory 72 cast iron intake,HEI,Hooker headers and dual 2.5 inch exhaust with X crossover.
The +30 thou pistons have a much shallower dish than the factory ones in the 1975 engine. Only identifying marks on inside of these pistons are 1631 with 88 under this number inside a circle and a large M or W on the opposite side. Are these Silv-o-lite 10.1 compression pistons or something similar ? And if so,are they ok to use ?
Could do with some advice on camshaft choice for this set up,something a bit better than stock with fairly smooth idle and good mileage if that's possible ? I'd been thinking of a Comp Cams High Energy CL42-229-4
Paul
I have got hold of two 455 engines that i've stripped down and plan to make one good one out of the two.
The first is a tired 1975 engine with J heads that had never been apart before.
The second is a 1972 engine with Ga heads and nodular crank that has fairly recently been apart and rebuilt with +30 thou pistons but has had stitch repairs done to repair frost damage to the block.Head gaskets were leaking on this engine and block looks a bit suspect !
My plan is to have the 1975 block bored +30thou and put the nodular crank,rods and almost new pistons from the 1972 engine into it with new rings and bearings.Topped off with the Ga heads (egr/air bumps ground down,new valve guides etc)factory 72 cast iron intake,HEI,Hooker headers and dual 2.5 inch exhaust with X crossover.
The +30 thou pistons have a much shallower dish than the factory ones in the 1975 engine. Only identifying marks on inside of these pistons are 1631 with 88 under this number inside a circle and a large M or W on the opposite side. Are these Silv-o-lite 10.1 compression pistons or something similar ? And if so,are they ok to use ?
Could do with some advice on camshaft choice for this set up,something a bit better than stock with fairly smooth idle and good mileage if that's possible ? I'd been thinking of a Comp Cams High Energy CL42-229-4
Paul
Registered User
Joined: Sep 2012
Posts: 776
From: chicago il
have your total compression around 10 to 1 or a little lower and think about a jm mondello 18-20 or 20-22 cam both are excellent and get decent mileage for a olds that is also the power will be around 340 wheels with the 18-20 i have seen this on a dyno.
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Joined: Nov 2008
Posts: 8,477
From: Central Fl
If memory serves me right that piston is a cast Federal Mogul with a 13cc dish but has about .020 less compression distance than most other aftermarket pistons. With an 80cc head it should give you about 9.5-9.75:1. Just about what I'd recommend on an iron headed mild build.
Imo an Erson TQ20 would be the perfect cam for you. It's 214/214 at .050 with .477 lift and will work well with all your stock stuff.
P.S. just looked it up, yes that's a Silvolite piston. But it does have the short compression distance as mentioned.
Imo an Erson TQ20 would be the perfect cam for you. It's 214/214 at .050 with .477 lift and will work well with all your stock stuff.
P.S. just looked it up, yes that's a Silvolite piston. But it does have the short compression distance as mentioned.
Last edited by cutlassefi; Nov 27, 2012 at 06:17 AM.
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