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Engine was replaced in '72 LT 1 with 1995 crate motor by previous owner. Car has set up for at least 15 years. Would like to rebuild motor with original type cam and lifters. How does the crate motor 8 to 1 compression ratio affect performance? Is this compression ratio to low for this cam, also what are the original cam specs for the original camshaft?
So this crate motor ran for 7 years? Daily driver, or occasional use? also, how do you know the specs on this crate motor? Many were decent performance engines, not just bottom of barrel cast low compression smoggers...
You will need to figure out the manufacturer of the engine, get some numbers off the passenger side front pad and go from there. I don't believe anyone on this forum can help with the engine & cam specs with only the year it was made. And yes, 8 to 1 CR is just awful.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
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the 70 had 11:1 compression, the 71/72 had 9:1 compression. Using the LT1 solid lifter cam will change the performance but you wont get the 330 HP that it once had without the higher compression piston and low volume head. You can change the heads as well and that would help a huge amount because the 8:1 compression probably has over 72cc of volume. I would find some low 60cc volume heads ( 62 or 64 cc). Newer heads will flow better as well which will boost HP. Try the bolt on stuff first before rebuilding the bottom end
You can go to the comp cams website or crane cams site and look for nostalgia muscle car/performance cams
If you are thinking about putting LT-1 parts in the crate engine because the car was an LT-1 car (when it had its original engine), forget it. With any other engine than the original, you might as well install modern/better technology if you are trying to increase performance. New aluminum heads, roller cam/lifters, appropriate pistons and headers/exhaust will give you the power you are looking for. And, you can configure the outside of the engine so that it still "looks" like an LT-1 engine.
Putting LT-1 parts inside a non-LT-1 block, does not an LT-1 make.
Last edited by 7T1vette; Apr 10, 2018 at 12:39 AM.
If you are thinking about putting LT-1 parts in the crate engine because the car was an LT-1 car (when it had its original engine), forget it. With any other engine than the original, you might as well install modern/better technology if you are trying to increase performance. New aluminum heads, roller cam/lifters, appropriate pistons and headers/exhaust will give you the power you are looking for. And, you can configure the outside of the engine so that it still "looks" like an LT-1 engine.
Putting LT-1 parts inside a non-LT-1 block, does not an LT-1 make.
Not necessary, maybe..... but there are enough problems reported here with rebuilds using flat tappets and getting early wear-outs that it would be "necessary" if I were rebuilding the engine for my Corvette.
The OP will do what he/she wants. I'm merely offering suggestions / advice.
Last edited by 7T1vette; Apr 11, 2018 at 07:16 AM.
Bump up your compression
Trick Flow makes a real nice aluminum heads that has the double humps cast into it. Paint them up noone would know
Upgrade to a modern SFT or HR cam youll look back and say LT What?