Engine BREAK- in

#1

Recommendations on new rebuild break in.Will be changing it befoe JULY VIR.Oil change period,rpm limit,weight of break in oil.
I am in hd-3 & want to do TT or comp. school soon.
Have 14 weekends so far.
Thanks,Rick Cofer
1988 325IS #84

#2

My break-in plan involves about 15 minutes of light revving after rebuild with SAE30 oil. Drain oil, change filter, replace both with new. Drive the car pretty hard, vary engine speed, allow engine to slow car (not putting it in neutral to coast or stop) with the engine oil of your choice for a couple hundred miles. Drain oil, change filter, refill oil and don’t look back.

But that is my plan, others may have their opinion.

#3

Use a break in oil additive. From what I understand, if the cam and rockers don’t get an initial coating of ZDDP you can cause significant damage in the first 30min.

#4

I’m not going to get into the oil debate (that’s Scott’s territory). The break in that I use is to prime the oil system by spinning the pump, warm up the engine to normal operating temperature, and then hold it at 2500rpm for 20-25 minutes. Change the oil and filter and the engine is “good to go”.

#5

When I rebuilt my engine, the machinist who did the work recommended I use Brad Penn break in oil for the first 500 miles, then switch to Brad Penn racing oil. It has the ZDDP additives in it.

#6

As an engine builder for the past 35 years, I suggest you don’t worry about ZDDP. That only applies to flat tappet motors and yours doesn’t qualify. Think VW or Porsche 356. Any decent 30 weight NON-detergent oil is fine for break-in. The only reason for break-in is to get the rings to seat in the cylinder wall. Once the cylinder wall is conditioned by the rings the break-in process is complete. Then switch to a brand name detergent motor oil or, better, something like Mobil 1.

#7

Thanks for the info.

I was going to wait until July to change the engine. But now am signed up for Summit Point (was on a waiting list).

The engine is now placed back in the car and I will begin the break-in process tomorrow.

After a couple of hours at below 2500 rpms, do I need to limit the rpms for any longer timeframe?

Will it be ok to use detergent oil for the initial break-in?

Thanks again for your input.

Rick Cofer:woohoo:

#8

Detergent oil is Ok for initial break in as it is pretty hard to find non detergent oils anymore. Your “couple of hours” at lower rpm is ok but don’t be too scared to let it rev some more.

The only other advise I might add is to do that process twice before racing and/or introducing synthetic oil just to be sure to get all the assembly lube, any shavings, or any new part wear out of there before pouring on the coals.

Don

#9

Update.
Other than chasing a miss for a weekend{bad injecter}things went well.I was able to get a couple hrs. on the engine before Summit Point.The first day i did limit the rpms to 5500.The second
day no mercy.Op at red line 65 psi.I did have to change a water pump gasket Sat. evening.other than no hick-ups.
I will be doing comp. school at vir,in a few days so a few tips pleaseeeeeeeeee.For all of my hd events i have been on R888s.Have a set of RA1s
ordered.Still have a day or two on the 888s.Is there much difference in the diff. types.
If i can pass comp. school you guys will have some “new” well aged meat to feast on sat. enjoy, because I know i will be having fun other than the heat that is forecast.:woohoo:
Thanks: Rick Cofer

#10

From past threads I have read. Know the CRR front to back especially the flags. Whatever you do DO NOT GO OFF TRACK.

#11

King Tut wrote:

Or spin, or hit someone…

#12

Glad you decided to do the Comp School thing Rick. Have a great time!