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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: COREY13 on April 13, 2016, 03:32:19 am
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So when rebuilding my engine i had a series of unfortunate discoveries that led me to trashing the block i had and getting another motor. The motor i got was from a buddy and i heard it run and the motor had about 80ish thousand miles on it. Checked the compression and and it was good so all i wanted to do was freshen it up a bit, with new head gaskets, front and rear main seals, freeze plugs, etc... But ( theres always a but) when i pulled the oil pan off, i decided to give the rod caps a feel and i had some movement in them, my question is, how much is too much movement? I can grab every rod cap and move it a little, its not extremely loose, but it has a little play. Im just wondering how much play is acceptable. Any help would be great, or advice as to what i should do. I was thinking about maybe replacing the bearings, but i might as well put new rings on while im at it. Like i said advice would be greatly appreciated.
Thanks
Charlie
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Just thought i would add, the rod caps are not loose, thats not what i meant by movement, i meant that there was some play in the connecting rods
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What kind of motor are we talking? Just a basic 350? Is so then there should be a little play in there. What you want to check (if you can) is to make sure it's not just the rod cap and larger side of the rod. Try to get a light in there and make sure the whole rod moves in unison on the pin. That being said, fresh bearings and rings is always a good idea when you have the access to them. The little money they cost is well worth the peace of mind. If you go this route I would recommend a coated bearing like clevites. And pay close attention to your clearances.
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Use a feeler gauge to measure side clearance. Use plastigauge to check bearing clearance
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Plastigauge the bearings if it makes you nervous.
80k isn't that much and you said you heard it run. What was the oil pressure? Not having seen the engine personally, and going with your description, and add my experiences, I'd throw the pan back on it and fahgeddaboutdit.
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Thanks for all the input, im not sure what the oil pressure was, honestly i forgot to look. I was thinking about it and i have a re-ring kit i bought from summit that is for a gen 1 350, and after some research it looks like the only 2 things that wont work for what i have now is the intake and valve cover gaskets. Am i correct on this? Im putting on a edelbrock high rise and getting rid of the tbi intake, and im also going to be installing an electric fuel pump and regulator. Im just wondering if the rest of the gasket set will work (ie head gasket and oil pan gasket etc) and the piston rings and bearings that came with the kit will fit. My understanding, which could very well be wrong, is that most of the differences between the 70s and 80s 350s and the late 80s early 90s motors is on the top end with the yay the intake mounts and things like that, but the internals are pretty much the same. Please correct me if im wrong.
Thanks
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If your 80k engine is a TBI engine it will have a one piece rear main seal.
Oil pan gasket and rear main seal are not compatible if the gasket set is for a 1st generation (pre 1986) small block.
(Crankshaft and blocks are totally different)
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Ok so all i should need is the oil pan gasket, a rear main seal, the intake gasket, and the valve cover gasket? If thats the case then i can live with that. So i should be ok using the rod and main bearings, piston rings, and the head gaskets?
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Ok so all i should need is the oil pan gasket, a rear main seal, the intake gasket, and the valve cover gasket? If thats the case then i can live with that. So i should be ok using the rod and main bearings, piston rings, and the head gaskets?
Yes those parts interchange. You should also be able to use your intake gasket. The only difference in the pre 86 and post 86 heads and intakes is the angle of the mounting bolt holes.
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