Learn me: Break-in oils. Myth? Recommendations?

OK, the saga of the total n00b with a 1st-grade-level knowledge of engines trying to build a racecar continues.

The car is an '87 Mercedes 190E 2.3-16 (with the twin-cam Cosworth head). Had a race engine built over the winter with higher compression pistons and more aggressive cams. These engines run solid lifters with a shim-under-cup design. I've been told break-in is critical. Trying to figure out the best/safest way to break-in the rings and cams.

I've come across the notion of "break-in oils." From what I gather, these are non-synthetic oils with lots of ZDDP. Should I be looking for something like this?

I've seen specialty break-in oils by COMP Cams, Joe Gibb, Motul, and Royal Purple. Lots of companies seem to offer break-in additives: Redline, Lucas, Crower, Crane, Total Seal, and Lunati. Are any of these recommended?

I generally run Amsoil Dominator RD50 in this engine. From what I gather, this would not be a good choice for break-in.

I've got a few liters of Valvoline VR-1 and Brad Penn PG-1 on hand. Both of them are known for high levels of ZDDP. Are they good enough, or is there more to "break-in oils" than just ZDDP?

There is way, way more to a real break-in oil than ZDDP. If you have a new, non-roller, camshaft and lifters then break-in oil and procedure is required. Generally you will start the motor for the first time and bring the RPM's up to 3000-3500 for 20-30 minutes to break-in the camshaft, then you will want to put 25-50 miles on the engine in varying loads and engine speeds to get the rings to seat. Once completed immediately change the oil and filter to flush out all of the assembly lube. Generally recommended to change the oil and filter again after another 100-500 miles. Being a racecar this might be a bit different, talk to your engine builder or machinist.

And on the flat tappet cam break-in bit, it's usually less of an issue for overhead cams that have less pressure on the lobes, but still a good idea to do it if you can. When you do that process, make sure the motor is primed and ready to fire right off so it doesn't crank for too long. And bring the revs up to 2500 or so immediately when it fires. Don't blip the throttle, don't let it idle even for a second, etc.

Javelin wrote: .... talk to your engine builder or machinist.

Or at least talk to the people you got the cams and valvetrain from. Do exactly what they tell you to do. Of the systems that you are breaking in, that's one of the more sensitive.

The other part you break in- the rings/bore interaction- whatever you do for the valvetrain, they will break in at the same time.

alfadriver wrote:

Javelin wrote: .... talk to your engine builder or machinist.

Or at least talk to the people you got the cams and valvetrain from. Do exactly what they tell you to do. Of the systems that you are breaking in, that's one of the more sensitive. The other part you break in- the rings/bore interaction- whatever you do for the valvetrain, they will break in at the same time.

This. Always default to the engine builder/manufacturer.

Thanks for that. What about the oil? Any recommendations?

We use Brad Penn 30w break-in oil in everything, even roller cam engines. (Disclaimer: We do not do flat tappets anymore, too much liability if they go flat, then you have to disassemble the engine to clean everything, if you're lucky, rehone/new pistons if you're not)

For an OHC engine with exponentially lower loading on the buckets compared to what even a mild flat-tappet pushrod engine can do... don't worry about the valvetrain, just the rings. OHC is waaaaay nice to the valvetrain. 31-33mm bucket with a large diameter lobe acting directly on a light valve and a light spring, versus a small diameter lobe graunching a 19-20mm tappet that has to shove open a heavy valve and spring, against a heavy mechanical disadvantage. No contest!

Don't get hung up on "zinc" or "ZDDP". There are different/better compounds that do what ZDDP used to do, without the cat-killing effects of phosphates.

This info is the sort of thing that will be good to remember in case you get ICE nostalgia in the future

A certain race engine builder uses the Joe Gibbs BR30... their ring failure rate dropped in half when using the break-in oil

GameboyRMH wrote: This info is the sort of thing that will be good to remember in case you get ICE nostalgia in the future

Dude, rotaries...

I've heard nothing but good things about the whole Joe Gibbs line of products, except possibly for price. We've always had good results with Brad Penn so we continue to carry it as a product line.

Spoke at length with the engine builder. He recommended a straight 30 weight break-in oil. The only one I could find that meets his description is Brad Penn. But everyone raves about Joe Gibbs BR30, so I've decided to give it a try. It's 10w-30 instead of straight 30 (for whatever that's worth), but reviews seem favorable.

Nice car, I bet either diesel 15w-40 or any non detergent 30w will work fine. The mercedes uses non-roller cam rockers but it is still OHC so they don't run insane valve spring pressure which will wipe out a flat tappet cam without special oil. OHV pushrod engines run crazy valve spring pressures and need special oil or the cam will flat spot in no time, the mercedes not so much. My m110 uses metal to metal rocker arm to cam and I added a bottle of that zddp snake oil and I'll be damned if it didn't help quite the valve train down some. Good luck and get on Benzworld!

benzbaronDaryn wrote: Nnon detergent 30w will work fine

NO, NO, NO, NO, NO! There is absolutely no place for EVER putting non-detergent garbage in an engine at this point.

alfadriver wrote: Or at least talk to the people you got the cams and valvetrain from. Do exactly what they tell you to do.

Just got off the phone with them folks at Cat Cams UK. They recommend:

1. slather the cam lobes and lifter surfaces with heavy-duty rear diff lube.

2. run the engine between 1500-2500 rpm for 5-15 minutes.

3. drive gently under load for 45 min to an hour, keeping revs under 2500 rpm

4. change oil and filter

5. profit

What do you guys think?

LanEvo wrote:

alfadriver wrote: Or at least talk to the people you got the cams and valvetrain from. Do exactly what they tell you to do.

Just got off the phone with them folks at Cat Cams UK. They recommend: 1. slather the cam lobes and lifter surfaces with heavy-duty rear diff lube. 2. run the engine between 1500-2500 rpm for 5-15 minutes. 3. drive gently under load for 45 min to an hour, keeping revs under 4. change oil and filter 5. profit What do you guys think?

if this is a new engine (rings as well as cams...) #3 may not set the rings. "gently under load"??

LanEvo wrote:

alfadriver wrote: Or at least talk to the people you got the cams and valvetrain from. Do exactly what they tell you to do.

Just got off the phone with them folks at Cat Cams UK. They recommend: 1. slather the cam lobes and lifter surfaces with heavy-duty rear diff lube. 2. run the engine between 1500-2500 rpm for 5-15 minutes. 3. drive gently under load for 45 min to an hour, keeping revs under 4. change oil and filter 5. profit What do you guys think?

Sounds about right to me. I'd shoot closer to the 2500 rpm and 15 minutes side of step 2.

I would do exactly as they say!!!

By the way you can not just be talking about a 16V 2.3 Merc motor with a Cosworth .. .. . . . .. . .. (Sorry I needed a moment to gather my self) head. WITH OUT PIX!!!!!!!!

benzbaronDaryn wrote: Nice car, I bet either diesel 15w-40 or any non detergent 30w will work fine. The mercedes uses non-roller cam rockers but it is still OHC so they don't run insane valve spring pressure which will wipe out a flat tappet cam without special oil. OHV pushrod engines run crazy valve spring pressures and need special oil or the cam will flat spot in no time, the mercedes not so much. My m110 uses metal to metal rocker arm to cam and I added a bottle of that zddp snake oil and I'll be damned if it didn't help quite the valve train down some. Good luck and get on Benzworld!

This is the single worst piece of advice on GRM this year...

LanEvo wrote:

alfadriver wrote: Or at least talk to the people you got the cams and valvetrain from. Do exactly what they tell you to do.

Just got off the phone with them folks at Cat Cams UK. They recommend: 1. slather the cam lobes and lifter surfaces with heavy-duty rear diff lube. 2. run the engine between 1500-2500 rpm for 5-15 minutes. 3. drive gently under load for 45 min to an hour, keeping revs under 4. change oil and filter 5. profit What do you guys think?

Agreed with the 2500/15 minutes and more than a "light load" for #3. I would also change #1 from rear diff lube to actual camshaft assembly lube like so:

dean1484 wrote: By the way you can not just be talking about a 16V 2.3 Merc motor with a Cosworth .. .. . . . .. . .. (Sorry I needed a moment to gather my self) head. WITH OUT PIX!!!!!!!!

I've got lots of pics in my build thread over in the Projects forum: '87 190E 2.3-16 build

Here's a quick teaser from this week:

rslifkin wrote:

benzbaronDaryn wrote: Nnon detergent 30w will work fine

NO, NO, NO, NO, NO! There is absolutely no place for EVER putting non-detergent garbage in an engine at this point.

Yes, there is: Breakin, where you are only going to have the oil in the engine for a manner of minutes of run time. You don't want any "stuff" to stay in the oil (what detergents do) because you're not going to get all of the breakin oil out when you do the first oil change.

After breakin, yes, don't use non-detergent.

Knurled wrote: Yes, there is: Breakin, where you are only going to have the oil in the engine for a manner of minutes of run time. You don't want any "stuff" to stay in the oil (what detergents do) because you're not going to get all of the breakin oil out when you do the first oil change. After breakin, yes, don't use non-detergent.

I'd MUCH rather have the breakin junk stay in circulation in the oil where it can get trapped in the filter and/or drained out when the oil is changed. Otherwise, you get crud settling to the bottom of the oil pan where it typically stays until you remove the pan and clean it manually.

Knurled wrote:

rslifkin wrote:

benzbaronDaryn wrote: Nnon detergent 30w will work fine

NO, NO, NO, NO, NO! There is absolutely no place for EVER putting non-detergent garbage in an engine at this point.

Yes, there is: Breakin, where you are only going to have the oil in the engine for a manner of minutes of run time. You don't want any "stuff" to stay in the oil (what detergents do) because you're not going to get all of the breakin oil out when you do the first oil change. After breakin, yes, don't use non-detergent.

Most break-in oils are SAE 30, however that does not make them "non-detergent". None of the commercially-available break in oils I stock are non-detergent. In fact, the only things left that use non-detergent should be air compressors, and the only non-detergent oil I sell is specifically called "air compressor oil".

Ironically enough, we use Brad Penn 5W30 in the shop air compressor....

Good to know about the current crop of breakin oils.

Ive heard a lot of contradicting info, with break in oils and periods. Ive got to the point if its a roller motor, i drop some decent conventional in it, run the piss out of it for a few hundred miles, drain it and put the good stuff in it.

Break in oils and procedures are super important on flat tappet cam motors though