Break in oil

[Walter F.]

Just saw a show where they rebuilt and engine on a 1967 car and the mechanics said they always put break in oil in anew motor. I thought that was something done in the 1950s because the oil was not refined as well as mordern oil. I bought several new cars during the past 10 years and the dealer never said anything about removing the break in oil after several hundred miles. You guys who rebuilt your Corvette engines did you use break in oil. Does such a product exist.

[Keith B.]

Re: Break in oil

Modern engines with roller cam shafts and lifters do not need a break in oil. Flat tappet cams do. Brad Penn, Joe Gibs oil and others make good break in oil

[Duke W.]

Re: Break in oil

Some "mechanics" haven't learned anything new since the fifties.

Modern moly faced ring sets, in use by GM since the seventies, don't need a dedicated "break-in". The same goes for OE camshafts. GM did not do a "cam breakin", but running the engine on initial start at 2000 for 20 minutes while you check for leaks and proper cooling is not a bad idea.

Just use 15W-40 CJ-4 for the initial fill, and a pint of GM EOS is optional. Change the filter after the first couple of hours of operation as it can get clogged with assembly lube and debris, but don't change the oil. Just top it off and run the normal distance of a few thousand miles or one year, whichever comes first.

Duke

[Roger W.]

Re: Break in oil

On the show "Fast And Loud", The Gas Monkey Garage Had a 302 rebuilt by an engine rebuilder in a 68 Shelby GT350. They tried to save money by using an inexpensive oil and using some kind of break in additive. When the engine was started it made a big clatter. The cam shaft had failed. The engine went back to the rebuilder and a new cam installed. Then they used break in oil and the engine worked fine.

[Walter F.]

Re: Break in oil

Yes grease monkey is where I saw the story. My brother last year a retired mechanic for over 50 years just rebuild his engine in his 57 Ford Fairlane 500. He used a good grade of 10-40 oil after the rebuild even though Ford says straight 30 weight is what they recommend. He said the straight 30 weight oil does not have the detegerants the multi grade oil has. That was last year. Car runs find no knocks no oil burning. That is why I question this break in oil thing. As far as I know the car has the stock cam, pistons etc. He keeps the car as orginal as possile.

[Duke W.]

Re: Break in oil

Your brother is incorrect. The additive package is a function of the API service category, not the viscosity grade. If he used a 10W-40 it was a SM or SN oil, not a CJ-4. He's way behind the power curve on current oil formulations.

As far as this TV story is concerned, it seems some have concluded that "cheap oil" was the cause of the problem. Poor quality parts (like improper hardness of the lobes or lifters), excess valve spring force, or improper installation is not a possibility?

Failed cams in rebuilt engines are not that uncommon, and it's usually blamed on the oil, but if all the facts come out it usually turns out to be component quality, component compatibility, or installation issue.

Certain aftermarket cam manufacturers seem to almost always be a part of these stories. That's why my first choice for replacement cams is either Federal Mogul (Sealed Power, Speed Pro) or Dana Corp. (Clevite), both of which are Tier 1 OE suppliers. If you want an aftermarket or custom design I have had good experience with Crane.

Here's an example. A local chapter member recently had his 327/300 heads rebuilt by what was supposed to be a reputable shop, and he went over the parts list with me after the job was done. I was not familiar with the parts supplier, but they do have an online catalog, and from what I was able to determine the new valve springs are equivalent to the 3927142 spring that was designed for the Tran-Am racing cams. I told him he needed to get them out of there and replace with OE equivalent springs before a cam lobe got wiped out or rocker studs started pulling.

It turns out the head work did not solve the oil consumption problem, so the engine came out for a complete rebuild by another shop.

These stories are common. The archives are full of them.

Duke

[Dick W.]

Re: Break in oil

Break in oil is one of the biggest fables out there. Maybe 60 years ago it was necessary but not in modern times. Over 40 years ago when I was in fleet maintenance, we had problems with one manufacturers engines and I requested a piston ring engineer to visit with us. Even then he said the policy of break in oil went away once manufacturers improved their tolerances and the advent of modern piston rings.

I am with Duke, CJ oil and maybe GM EOS. I call BS on the Gas Monkey engine. They did something wrong in assembly. I have built many engines in the last 55 years and never had a camshaft failure. I always used a cam lube on the lobes and lifters, never let the engine idle for the first 30 minutes, after that it was what ever the engine owner wanted to do with the engine.

[Michael J.]

Re: Break in oil

Interesting discussion, I have always used a CJ-4 oil with a bottle or two of ZDDP additive for the first 1000 miles or so and changed as Duke described. Never had any issues.

[Domenic T.]

Re: Break in oil

Sometimes fast & loud is a little hard to watch, but also interesting.
My experiance tells me a cam failure at start up would be a poor choice of parts or assembly.

DOM

[Jack H.]

Re: Break in oil

Sometimes fast & loud is a little hard to watch, but also interesting.
My experiance tells me a cam failure at start up would be a poor choice of parts or assembly.

DOM

Agreed on the Fast & Loud/Gas Monkey show. I enjoy it, but it also frustrates me and has me shaking my head at times. I have to keep reminding myself that it's a TV show designed for ratings. You really can't put any validity in anything technical on the show as its about drama, a story, and ultimately TV ratings. In other words, watch it for entertainment only and with a healthy dose of salt.

I sure wish I could find/buy the cars they come up with at the prices they pay. Wow.

[Paul J.]

Re: Break in oil

Agreed on the Fast & Loud/Gas Monkey show. I enjoy it, but it also frustrates me and has me shaking my head at times. I have to keep reminding myself that it's a TV show designed for ratings. You really can't put any validity in anything technical on the show as its about drama, a story, and ultimately TV ratings. In other words, watch it for entertainment only and with a healthy dose of salt.

I sure wish I could find/buy the cars they come up with at the prices they pay. Wow.

For the most part, the prices are realistic. You have to consider the condition of those stoves that their buying. The sale prices are what is fantasy, since they chop the suspensions up and paint over the dirt underneath. They produce some real C***, but like you say, it's TV.

[Ken R.]

Re: Break in oil

When I picked up my new 65, dealer told me to change the oil at 500 Miles to Ashland non-detergent oil, which I did. Rest of oil changes I used a major brand 10W-30W. Engine ran great while I had it. Oils have come a long way since then. Anyone remember Bardall.

[Michael J.]

Re: Break in oil

When I picked up my new 65, dealer told me to change the oil at 500 Miles to Ashland non-detergent oil, which I did. Rest of oil changes I used a major brand 10W-30W. Engine ran great while I had it. Oils have come a long way since then. Anyone remember Bardall.

http://bardahl.com/products/oil-additives/special-duty

[John M.]

Re: Break in oil

Newer member here, am I correct in assuming there is a break-in period on a new engine even if a break-in oil is not required? I was under the impression that the computer on the C7 limits the rpm until the car has been driven a certain number of miles. Just curious.

[Michael J.]

Re: Break in oil

Don't know about the C7s, but for my 2012 ZR1, the break-in period was the first 1000 miles. Check the owners manual, but in mine it said to vary the engine RPM frequently, but not over 4000. Since I picked it up in BG for NCM delivery, driving it home the 1300 miles on I-40 had me running in 4th, 5th, and 6th gears back and forth the whole way to get the variations in.