I went about trading a set of SMOG heads for a disassembled 350 short block. When I got it home, I checked the numbers. Pretty sure it's an L79 (service replacement?). The bearing surfaces show very little wear but the cam lobes appear, under close inspertion, to have just a little pitting. I read somewhere that it's considered damage and needs to be reground. My question is: can I toss in some break-in additive, new lifters (going with Rhoades), new bearings, and be fine? Also, what else should I check and how do I do so?
Never, Never, ever install new lifters on a used cam or install a new cam with used lifters. This goes for any flat tappet cam, period!!! They must break-in and match together. Also never mix up lifters and lobes after they are run. Doing so is a recipe for a disaster. Have your cam reground or buy a new one and replace the lifters and use a good break-in lube. Then run the engine for at least a full 20 minutes at 1800-2200 rpm. Don't idle it for long periods for the first 500 miles and you will most likely have a happy cam.
It might be fine, but I have to ask: Why would you spend money on new lifters and bearings, with the chance that if the cam goes, it is going to take out those new parts, not to mention what the metal in the oil might do to the oil pump, main and rod bearings, etc. New cam seems to be cheap insurance to me, but people always want to get by as cheap as possible, then bemoan their bad luck when they spend a ton more to fix it afterward.
Is it from rust or the lobes worn, check them with a micrometer, SBC cams are a dime a dozen, pulling the pan takes a while, replace the cam........ 2X, never mix used/ new lifters with new / used cam......
ive used a old cam with new lifters and vise versa hell ive sanded rust off a cam and used it never had a problem with it poor people have poor ways
Anybody know where I can find a cam grinder near Glasgow, Kentucky? Is it gonna be worth it to have it reground or just buy a $130 cam and lifter kit from Howards Cams? Just tryin to cheap out.
One of the nice things about playing with sbc engines is that the parts are plentiful and cheap. I hate tearing an engine apart a second time, so I would say it would be cheap insurance to just put that new cam and lifters in there with zinc additive (for the rest of the engines life) and then you have a better shot at not having a problem. The older I get the less shortcuts and chances I take. I recently put a brand new 5.0 roller cam in the dumpster because it had some very mild pitting on it from being stored and I just wasn't about to take the gamble. Don
Match up a new (dirt cheap) cam to your vehicle for maximum power. Or scab it and stab it, run it Maynard!
"Back in the day" when motor oil was MOTOR OIL I ran a pile of cams with some pitting on the side of the lobes. I had a chart that showed acceptable pitting. The pitting was NOT on the top of the lobe or in the center of the ramp leading up. NOW I have started a collection of cams that look beautiful except one freakin lobe is GONE! ONE! Makes me so angry I just wanta..... ! Ok.... woo saaa woo saaa. Don't get me started on the shitty gas we have to buy! Peace
You are probably describing a perfectly normal sbc "cast" camshaft, they will have a pitting look in the lobes when they are new and as they wear. I have mix matched old lifters and new lifters many times and never had a issue but then again i know plenty of people that build all brand new engines and they dont last 100 miles.
I fail to see how 30+ years of poorly crafted general motors parts can be blamed on todays gas over and above the fact that gm small blocks have eaten 100,000 lobes from the factory. Blaming the extremely low quality of GM on gas 30 years after the fact is more than just short sighted in my books. -Of the hundreds of threads I have seen regarding worn cam shaft lobes, none have been in regards to Chrysler or Ford engines, I guess they don't have a problem with today's blended gas or poor gas from 30 years ago for that matter.
WRONG!! You evidently are not in the business.. I see damage on all brands now and particularly older trucks, tractors, work engines.. The old farmers and construction guys aren't knowledgable about the new crap oils and gas. Getting many of the older engines with lobes wiped off.. Valves receded into cracked seats..
I in no way related cam lobe problems to the gasoline problem we have now, i was just simply stating in agreeance that gaoline quality is beyond poor or acceptable.
Sorry for my late rant about gas HOWEVER the original question can (and will) be debated from now on. Mr Fuzz makes an excellent point about the Chrysler and Fords (LOVE the av by the way). I worked in the machine shop of a auto parts store back in the 80's. After hot soaking engine blocks I flushed them out with water. When back-flushing thru the oil filter holes you could see how the oiling system compared between the GM, Dodge and Ford blocks. The Mopars flowed more than the Fords which flowed more than the SBC's. I am talking about v-8 blocks. No doubt that is one factor in this issue. peace
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