[llwta76]

I know there are different schools of thought on this but I'll be breaking in my new engine soon that has a new hyd flat tappet cam. I hear that detergent oil can wash away the moly paste on cam lobes but that non detergent isn't good for cleaning the assembly junk and debris and helping seat the new rings. If I do use the cheap non detergent stuff I will be adding ZDDP. Plan on dumping the oil right after cam break in. Also thinking on the Gibbs driven 10W30 oil . Trouble w/ that is they have so o o many different oils to choose from. Thoughts?

FYI : The last time I did this (10 yrs ago) I used the cheap SAE 30 non-detergent oil from Walmart without removing the inner springs on my solid flat I had then. Seat pressure was 150# with 360# OTN. No problems with cam lobe wear after thousands of miles on that one.

[Chief of the 60's]

Uh, no. Use Rotella diesel oil.

[panhead59]

Amsol makes a good break-in oil. Its their only oil that isn't synthetic.

[Formulajones]

Lots of good break in oils on the market specifically for this job that takes all the guess work out of it.

[mgarblik]

You are going to get dozens of conflicting posts about what to use. Be aware though, that Rotella Diesel oil has greatly reduced ZZDP amounts to comply with diesel particulate traps and emission reduction. So, unless you have a stash of 15 year old Rotella oil, I would add a ZZDP booster to it. Still good oil. For flat tappet engines, I am now recommending specific oil designed for break-in. Over a dozen different brands are out there and should work fine. Non-synthetic oil with lots of ZZDP seems to be the best for break-in now. That's what we use on the dyno and for the first runs on the street.

[John Milner]

I have had good luck with Joe Gibbs Driven break in oil. I personally think any help you can give a brand new engine during break in is worth the extra cost. $50 for break in oil is cheaper than changing a cam and the headache it causes when one goes south.

[geeteeohguy]

What these gents said. Use a good current break-in oil with plenty of ZDDP. Non-detergent oil has no place in any engine. We know better now.

[PunchT37]

I’ve always used straight 30w for break in. With a bottle of GM EOS if you can still find it. I change the filter only after cam break in and leave the 30w/eos in for 500 miles or so. Then, drop the oil and filter and go with what you’re gonna run.

[65blackplate]

Not sure if its true or not but the VR straight 30 is said to have a higher amount of ZDDP in it..

[thepontiacman]

Check company you get your cam from on warranty.

Zinc Additive, most cam companies have their own brand. Comp also has break in oil that has this additive.

[Formulajones]

I've used Comp, Brad Penn, and Amsoil break in oils and they have all done their jobs.
I use it regardless of flat or roller cam to break an engine in. There are still many high pressure areas in an engine like pushrod ends, rockers, piston skirts, etc.... And some of these break in oils have additive packages in them that promote or help ring seal as well. No need to add anything else to them.

With these engines costing $6-$10,000 to build anymore it just makes better sense to use a break in oil designed for this purpose. I can't see trying to save a few bucks at this point. I generally buy a case of it, use the first half to run the engine in and dyno it. Cut the filter open, change the oil again with the rest of the case, and put a few hundred street miles on it.

[Goatracer1]

The reason old cars used an oil without a detergent was because a lot of them had no oil filter. The detergent holds the contaminants in suspension until the oil goes through a filter. Non detergent oil allows the contaminants to settle out of the oil into the oil pan. You don't want the junk staying in the oil and traveling through the engine.

[hobbygto65]

Nondetergent oil was for engines that were made before hydraulic lifters came along.

[Dragncar]

Originally Posted by mgarblik

You are going to get dozens of conflicting posts about what to use. Be aware though, that Rotella Diesel oil has greatly reduced ZZDP amounts to comply with diesel particulate traps and emission reduction. So, unless you have a stash of 15 year old Rotella oil, I would add a ZZDP booster to it. Still good oil. For flat tappet engines, I am now recommending specific oil designed for break-in. Over a dozen different brands are out there and should work fine. Non-synthetic oil with lots of ZZDP seems to be the best for break-in now. That's what we use on the dyno and for the first runs on the street.

There was a thread about 10-40 oil and someone brought up a link to a big oil study. It had zink, phosphorus, and ZZDP.
But when extra zink was added to the oil, wear went up.
Its like the oil was designed to run as is with no additives. I use Lucas oil treatment in everything I own. But that test made me think.
The diesel oils, Dello 400 had better numbers than Rotella in that test.

[F ROCK]

this guy has claims about break in oils
https://540ratblog.wordpress.com/