I have a older "running" small block chevy engine that I think could be used as-is for driving and crusing NOT RACING. but i'd like to freshen it up. My question is.... If I go and change the timing chain and gaskets..... can I change the rings and bearings without having to go and get machine work done on the block and crank? or just run it till it NEEDS to be rebuilt? its a little tired but runs ok........ Im workin with a budget so I cant just run out and buy a crate motor or get a premium rebuild. what do you think?
Check your journal sizes on your crank, matched w/ the bearing sizes...also check the cylinder wear w/ an inside mic and see what it looks like. If the journals haven't worn down, I wouldn't mess w/ bearings. There will be a ring lip at the top of each cylinder. You can just hone most of that out...I'd at least invest in a new set of cylinder rings. I'd tear the heads down and check the valve guide clearances to make sure they're not worn too much. Also, lap the valve to reseat them properly. With the head loaded and off the block, you shouldn't be able to get a feeler gauge in between the valve and the cylinder head. Put new valve stem seals in as well. Also, check your camshaft bushings in relation to the wear on the cam. As long as everything looks good, I'd put a new set of gaskets on her, along w/ new rings, lap the valves, and give her a fresh paint job, and slap 'er all back together. Helpful?
Were it mine, I'd give it rings, bearings, gaskets, and new chain and gears. It's out right now--are you really that anxious to yank it out of your car a week/month/year from now? Also, a sbc is still the cheapest engine in this part of the world to freshen up. It's not like the parts would cost much. Besides, I've known guys that tore an engine down under the same cir***stances, just to "freshen up an already good running engine", and upon teardown found something like a piston with broken ring lands that would have been a real pain in the *** down the road.
freshening an old motor is a pretty broad subject. there are a few things you can check with the right tools... a feeler guage, plastiguage and a Haynes SBC rebuild book if the motor is covered in gunk, you can pretty much write the motor off as a core (just my opinion). if the motor is relatively clean and spins w/o ANY binding throughout its 360 deg rotation, the bearings/rings are probably OK.. although, in regards to the rings.. it is no way to check for excessive wear. how was the motor stored? how long was it stored? did the previous owner claim it was a low mile motor? did he look shifty? how do the spark plugs look? (excess oil on any of them?) did you see/hear it run? i rolled a 307 chevy with bad rings... it'd smoke like a mother****er coming off the freeway, it was like that for at least another 1000miles until i sold it... the new owner drove it home, no problems aside from smoking..
If your'e looking to do it on the cheap, I'm with hsheartaches. I would use a ridgereamer and go 10+ on the rings filing the end gap to spec. Good luck..........
Lemme make an addendum... if its a 305 or a 350, just get it running nice and beat the **** out of it. If its a 327, sink a bunch of time and paychecks into it!
Find a friend with a leakdown tester and leak it. If it's been sitting, fog the cyls with WD40 and spin her over by hand a couple of times. If you have no cyls higher than 30%, change the oil pump, pop it in and go. If you are going to tear it apart, there's about a 98% chance you're going to do a full machined rebuild. Most lo buckers don't like to admit it, but that's normally how it works...
Yeah if you're planning on re ringing it hell man, machine it and instead of being half ***ed and runnable it'll be a new fresh engine.
If you tear it down, might as well go all the way....expecially seeing how cheap SBC engine kits are.
I didnt want to just BUY a rebuild..... I dont know much about engines but I'd like to Do-It myself as much as possible
What kind of oil pressure is it showing,when up to operating temperature,at idle and at 45mph ? Compare it to what the manuals say it should be. If it's very low (50% below normal) it probably needs bearings.
Check compression, if everything looks good I can help you go through the heads. I have the spring compressor tool. I just did this exact thing on the replacement motor I put in the Commander. clean and paint everything Go through heads checked ridge new water pump and fuel pump Gaskets etc... It runs like a champ. So I guess the budget comment means you don't want to buy the 383/5sp??
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