razman

getting ready to break in a new cam and lifters (mechanical) on my L72 engine...two guys that rebuild motors that i respect have given my conflicting advice... one say use the moly on the cam, and the other says moly is too abrasive, and just use comp cams assembly lube for cam lifters....????? anyone care to weigh in? thanks, Rick

Nowhere Man

What does the cam manufactur suggest. After all they made it

Nowhere Man

Also what did you end up doing with your problems.

razman

Nowhere man....this engine was already rebuilt, but never fired when i bought the project. so, i didn't purchase the cam that was in there. i did end up pulling the cam and had a groove machined in last journal so that it will now oil properly. i have determined that the cam is an Elgin, E905P which is there version of the original GM 3863143 cam, so i intend to put it back in. i don't know what Elgin recommends for break in lube on mechanical cam, but asked two local engine gurus, and have gotten conflicting reports. thanks for asking for the update! Rick

Nowhere Man

Alright I can't answer on break in lube. Did you verify that you have the correct cam barrings? 65-66 are by thems selfs. And are needed. If the first engine builder didn't put the groove in the cam I can bet he didn't know about the barrings. And truth be told I wouldn't trust anything else he did to the motor.

Pop Chevy

Moly disulfide is too abrasive ????? Say WHAAT? I never heard such a thing. I've used moly on every cam that I have put in for the last 40 yrs. Even when I worked at a Chevy Dealership in the 70's, GM had their own. Shoot, I even use it on Harley cams. In all that time, I've only lost one cam and Crane made good for it.

GOSFAST

Every flat-tappet cam we've broken in has been with "moly" lube (for the lobes and lifters), nothing else. I would not use any "lube" they supply.

We have not experienced a single failure for as long as I can recall. All of our builds are started on the dyno however.

The "old-school" rules also do still apply, it MUST fire immediately (no excessive cranking), reduced spring pressure's (when required), and keep the RPM's up.

Thanks, Gary in N.Y.

P.S. Today I also recommend using some dedicated break-in oil as well, we like the Brad-Penn line.

54greg

ALWAYS

razman

engine builder had machined a groove in the camshaft, but not near wide or deep enough...i had it machined to correct specs...3/16"x7/64" deep...how exactly would i be able to tell if the cam bearings are the correct ones? i can look down through the lifter galley and see that there is indeed a big hole in cam bearing in center bottom.

thanks to everyone for responses, i guess i will plan on using the moly for break in, and dedicated break-in oil with zinc.

JohnZ

Read this:

razman

with the aid of a small round mirror on extension, and small flashlight.....yes, rear cam bearing is grooved!!!

Nowhere Man

If the holes are lined up you should be good to go.

ohiovet

Molybdenum DiSulphide the lubricating ingredient in "moly" lubricants is in no way abrasive and is fine as a break in lubricant.

Out of school I went to work for Alpha Molykote in Stamford, Ct. and it was quite an experience. The test procedures were amazing (Falex tester being one) and there were tests run on engines after draining the oil. The owner at the time was Alfred Sontag who was a early proponent of MOS2.
Dow Corning bought us out and currently markets a line of Molykote lubricants which are great for extreme pressure (EP) applications as opposed to silicone lubricants which do not handle EP applications.

On my last cam I used the manufacturers break in lube.

pop23235

Which brings up a question. How did the factory break in these engines. I believe they were run on either propane or natural gas, but for 20 minutes to break in the cams? After installation of the engine, running to load onto the transporter and around a dealer lot would not be considered "good" to the engine.

JohnZ

The engine ran on the hot-test stand for less than a minute (on natural gas) while timing was set and it was inspected for leaks or noises. It never ran again until the car it wound up in was started, idled for 3-4 minutes, and was then driven off the end of the Final Line at the car assembly plant. Then it spent a couple of minutes being driven on the Roll-Test machine before it was shipped.

That's why GM factory camshafts had the lobes Parkerized to better retain residual oil while the lobes and lifter faces got to know each other better.

pop23235

Thanks John. You filled in the missing info I'd learned (actually from Ford) as they must do the same or similar.

Also explains the finish on the new cam I put in my 64/365 in ~'75. Bought a CE block and could only order the 350 hyd cam version at the time. I bought the cam and lifters to change and the cam came with this black/rough finish I wasn't expecting. Since I didn't start this engine and will hope to do it this year, at least now I understand the rough finish on the lobes. Lest anyone worry, I'll disassemble and inspect this engine before starting after all the years of storage.

cardo0

Smokey Yunick used a high press lube (in his power secrets book) i think it was Molykote but not sure 'bout it as Dow Corning product. Well nearly everone in the lube and camshaft business has something to sell ya. Maybe more important is how u break in the cam & lifters. No low rpm! As soon she starts get it to at least 2,000rpm for 20 min. I like to vary the throttle during this to.
Strong vlv springs work against u but with a stock like cam the matching springs shouldnt be to harmful for this. If u did have high press vlv springs or double springs changing them to low press springs for cam breakin would be beneficial (Smokey said that to).

I just want to highlight the fact the time to get to 2000rpm is crucial as during startup of new/rebuilt motor so many items cause delays - water leaks, fuel leaks, oil leaks, ign failure. To share i lost a new flat tappet cam because my MSD6 box had a corroded terminal lug on the batt and all the slow speed cranking while trouble shooting this wiped the cam. Well maybe my higher press vlv springs didnt help. But i had a tick, tick, tick as soon as i came down from the 2000rpm run. Yes it wiped lopes that fast. Others may take months but unless all the lifters are rotating the lope will wipe. Once cam is broke in u can mark all the p-rods with a white marker (or whatever) and look for p-rod rotation.

Hope this can help.

cv67

Always used Moly even putting new lifters on an old cam never an issue
Cant say the same for the red stuff washes off too easy I dunno. Everyones got their fav sauce. Only run rollers today

Pop Chevy

I also have to add that when I worked at a GM dealership in the early 70's we would change cams on average 2 cars a week. I got pretty good at it and GM usually paid. There was a rash of bad cams or maybe bad prep.

MikeM

I've read here on this forum that if a cam goes flat that it's necessary to pull the engine and strip it down and flush the metal shavings out of the block, then re-assemble.

I'm just curious what Chevrolet paid labor to do when cam went bad. I think I know. Just curious.