Graphite spray can be used on the cam lobe and lifters to help the assembly stick to the surfaces. I will look around for more cross references.

 

I know I have heard of this in the past but never paid it much attention. It seems like it's a better way to approach the break in since that article I posted previously correlated increased cam lobe temperatures with increased wear:

 

Monday update:
Rear main seal replaced, oil pan cleaned of gunk, gasket surfaces cleaned, lifters test fit for installation and rotation, cam lobes and bearing surfaces coated with "cam paste" and cam installed. I got my hands on some Brad Penn break-in oil. This week will be completing assembly and hopefully start up by the end of next week.

 

 

"Proof" for the unbelieving. You know who you are. SN and SM are the two last oil specs and they allow for triple the wear of the previous SJ and SL specifications that preceded.





So I took the oil "myth" myth and I

 

Something else I wasn't aware of, not only has ZDDP dropped... but detergents have increased. That's a double whammy.

 

Good luck on the break in! I am going to finish breaking mine in tonight. Old cam and new lifters for me. I used Rotella T4 with Lucas break in oil additive. That along with some Permatex assembly lube (Ultra Slick) that was applied to the cam and lifters. Should have plenty of good stuff to help it break in just fine.

 

I would still err on the side of caution with the high detergent oil. Like Lake Speed Jr. says, they compete for ZDDP. As long as you keep adding in more ZDDP it should be okay... theoretically. He makes mention that simply adding in an additive may not work like you expect. He said they have to be mixed at the right temperatures in order to disperse properly, so I have decided I will be running the HR 10W-30 synthetic they run after I break the engine in. It's a synthetic with all the properties of synthetic with the right blend of ZDDP for high lift flat tappets and higher spring pressures expected of the hot rod classic cars.

Technically the 4.0 valvetrain setup is classic/hot rod era technology. It hasn't changed since the 60's era 4.2 inline 6's.

https://www.drivenracingoilsales.com...synthetic-oil/

 

I agree with you. I forgot to bring home actual break in oil on Friday and could not source any over the weekend. I already had the Rotella so I just went out and got some additive. I know its not exactly the same thing as real break in oil but since my cam has already been used, I should, in theory, be fine. Most likely, I will put a few miles on this oil since its already in and then switch over to a real break in oil for the next 1000 miles.

Back when I used to build small block Chevys, I would use standard oil and add in a bottle of the GM EOS oil. Never had any issues breaking in cams that way, so this should be about the same. Me personally, I have never wiped a cam lobe or lifter and I have built a ton of flat tapped cam engines.

 

Why do you say this? Diesel engines with flat tappet cams don't have issues with cam longevity, and all they run are diesel oils.

 

I'm not a diesel engine engineer and I am sure there is more to the equation. I wouldn't put 10W-30 in said diesel engine. I've ran diesel engine oil and it always made my engine, and even the supercharger, scalding hot. It doesn't release the heat very well. Maybe that's desirable in a diesel, but heat is dangerous to an engine. Now that I think about it, don't they usually run oil coolers? See what I mean about engineering. It's not as simple as just swapping oil. You have to look at the whole picture. From what I have read in other places a lot of diesels don't even have cams. Diesels oils also have way more ZDDP, that's the reason they last longer

I won't run a diesel engine oil for the heat reason alone. Diesels have more build up in the engine anyways from nastier fuel deposits. That will bind up the detergents and "use them", freeing up the balance of ZDDP to do it's job. That won't be happening in a cleaner gasoline engine so the ratios are offset in favor of engine wear.

There's more going on in oils designated for specific engines than most of us are aware of. Viscosity is another thing. I wonder how many engines are dying off each year just because people think they know better than the designers. I used to be in that boat. I will be using the rightest possible oil I can from here on out for the 4.0 from now on. After watching a few hours of lubrication engineers over the past weeks while rebuilding my engine I'm not going to play at being a shade tree concoction chemist anymore.

EDIT: Half minute of searching and I found this page that lists the problems.

http://www.machinerylubrication.com/...l-engine-oils-

Excerpt at the top:

 

Although you aren't breaking in a new cam, you are breaking in lifters to an already broken in cam. I've read enough on the subjects where people argued against it to not be in favor of it.

Since the cam lobes already have wear and the lifters do not, that might increase wear on the cam. Breaking in a new cam with new lifters would be less stressful since they wear/mesh to one another in the process. I would skip the diesel oil and only run a 10W-30 with ZDDP, or get a proper break in oil.

I'm using a CompCam break in oil and adding in half a bottle of the Lucas TB Zinc Plus just to be on the safe side. CompCams specializes in cams, not lubes. Their lube for the cam didn't give me confidence in their lube abilities so I put some Driven grease on there. Maybe it's acceptable for the price point and the amount you get for someone racing engines and expecting to replace parts annually, but that's not the boat I want to be in.

 

You sure your information here is correct? Just want to point out that all diesels do have cams, some later engines have utilized overhead cam technology but they all have cams. Even the old two strokes (Detroit) have cams because even though they use cylinder porting for the intake they still use mechanical valves for the exhaust.

 

I would also point out the HDEO (diesel oils) can be had in the correct viscosities for the 4.0.

 

The Comp Cams additive is what I used and have used in the past. I finished breaking it in last night. So far so good. Probably have an hour run time by now. We will see how the next couple hundred miles go!