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seabass1858 09-12-2013 07:41 AM

Overhauled 4.2l Engine Break-in What oil to use?
I will be ready to fire up my freshly built .40 over 4.2l and was wondering what oil to use during the break in procedure. I used rotella 15-40 on my chevy 350s but this is the first master over haul where I actually changed out the cam and lifters.

Cutlass327 09-12-2013 08:17 AM

Regular 10w30 or 30w. No synthetics.

CSP 09-12-2013 08:18 AM

Joe Gibbs or Brad Penn oils. I believe that both have a break in oil with higher levels of ZDDP to help with the cam break in.

swatson454 09-12-2013 08:24 AM


Originally Posted by CSP (Post 15935105)
Joe Gibbs or Brad Penn oils. I believe that both have a break in oil with higher levels of ZDDP to help with the cam break in.


dirtdudeaz 09-12-2013 08:27 AM

Use a non-synthetic break-in oil. Mobil 1, Royal Purple, and comp cams are popular. Do the break-in procedure per cam instructions.

Drail oil, change filter, and put in non synthetic mobil 1 or rotella and run that for 500 miles. Repeat....Then change every 3K until 10K miles and then you can start to use synthetics. This has worked well for the motors I have helped with and am about to do the same on mine in a couple weeks!

seabass1858 09-12-2013 08:40 AM

good information to know thx.

Matt1981CJ7 09-12-2013 08:49 AM


If you are looking for a more readily available oil then the ones CSP mentioned, my dyno guys, who specialize in re-building older hot-rod engines, were very adamant about using Valvoline VR1 conventional oil in my 360.

The NAPA near me always has it in stock.


swatson454 09-12-2013 08:54 AM

Here are some links. I know it's more expensive but I don't trust any modern oils with the little "Approved" donut on the label (or whatever it says).

Driven Break-In Oil

and Driven HR1 for normal use

Or Brad Penn 15W-40


Edit: That might be a little over kill for a stock or milder cam profile but you'll be safe.

bkeese 09-12-2013 09:22 AM

What you need is 15W-40 CJ4 oil. It is the highest ZDDP of the readily available oils, or you can use the specialized oils as mentioned above.

seabass1858 09-12-2013 09:44 AM

what about chevron delo 400le 15-40?

Matt1981CJ7 09-12-2013 10:08 AM

Personally, I think the type of oil you use for break-in is a little over-blown. Think about it, you only run that oil for 20 minutes.

IMO, as long as you use a conventional oil with a zinc content of more than 1000 ppm, you should be OK. I think it becomes more critical for high-performance racing engines with radical cams, but we're talking a tractor engine here.

But that's just my opinion. Shawn would probably slap me right now, if he could. :p


swatson454 09-12-2013 10:22 AM


Originally Posted by Matt1981CJ7 (Post 15937833)

But that's just my opinion. Shawn would probably slap me right now, if he could. :p


:fight: LOL

That's the most critical 20 minutes that engine will ever see. Actually, if it's a stockish cam, you could run the expensive break-in stuff for the first 20 minutes and then drop down to one of the less-expensive oils like VR1, Mobile 1,... that sort of thing.

You might even be ok for the break-in, but that's not a chance I'm personally willing to take. No pulling and rebuilding a brand new engine for this kid.

Hey Matt, :tea:


Matt1981CJ7 09-12-2013 10:44 AM

How's it hangin' Shawn? :tea:

I'd like to point out that zinc (ZDDP) isn't the only anti-wear additive they put in oil. In fact, too much ZDDP can be a detriment according to Brad Penn. Phos and Moly are also used as anti-wear agents along with ZDDP. I think what's critical is the total parts per million of anti-wear additives.

This has some interesting data. As you can see, Lucas and Redline racing oils have the largest amount of anti-wear, by far. By comparison, there isn't a lot of difference in the rest of the "racing oils".


jdarg 09-12-2013 11:03 AM

I've used 5 quarts of conventional 10w30 and one quart of "break in" oil, i.e. Lucas on two motors now. I don't think it really matters if the cam was installed w/ proper assembly lube though.

seabass1858 09-12-2013 11:12 AM

I want to do this properly and I am trying to find a redily available oil. Advance, Autozone, and O'riely are the only auto parts stores around me. theoreticaly if i can get out of work at a decent hour to finish installing my rockers I would be installing the engine tomorrow and startup on saturday.

The time now is 08:50 AM.

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