OEM Initial engine break-in procedure.

[Retracnic]

Greetings,

I would like to know the initial engine break-in procedure used by major automobile manufacturers or their suppliers.

I am intimately aware of the procedures employed by race and performance engine builders. What I am looking for is what do the big guys (Toyota, GM, Honda etc) do to break-in an engine before it leaves the factory.

Any help would be appreciated in this matter

Regards,

Bryan Carter

PS – I know what the owner's manual says...

 

[GregLocock]

Oh, I was commenting on "The OEM's that use syn don't bother?" but I missed the question mark. Damn, so that's 65 years of an unblemished (yeah I bet) record.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Rob45]

Speaking of break-in oil:
when I had responsibility for engine tear-downs at Chrysler engine development, we often disassembled new production engines to use as bases for test engine build-ups.
Zer-mile engines that had only seen the engine plant hot-test run of 30 seconds or so.

I was horrified to see the amount of swarf that was left in the oilpan - a mixture of metal shavings, core sand, and just plain dirt.
Since that time I have immediately changed the oil and filter upon getting home with any new car, truck or motorcycle.
-----------
And on a related note, I have observed that vehicles that had been used extensively for passby noise testing had much lower oil consumption than one might have expected. I attribute this to the brief high-rpm/light-load operation they saw in the noise tests.

 

[evelrod]

OK...the engine went together faster than I had expected and I only bolted up the flywheel/clutch (minus the clutch plate ONE time...dumb, dumb, dumb (seems like I could learn this sh**).
Leak down after about a minute of turnover on the starter motor, sans sparkplugs, (oil pressure was 35psi) gave about 15%.
Leak down after a couple minutes to set ign. timing then about 15 minutes of high idle > 2000 rpm (oil press 95 psi) to warm up stuff (set valve lash warm) and another 5 minutes of 1500 to 6000 full throttle "pops" then to a low idle (barely) for a minute and shutdown...< 5% ! This indicates that, along with the fact torque to turn it over (sans plugs) is 10 ft/lb to break and <5 ft/lb to keep it rotating !!!!!!!
Man, I'm hoping for good things here. Leak down should drop to <3% and cranking pressure will probably still be in the mid 260 psi range, even with the 310 cam (CR is 13.87:1).
Can't get dyno time until next week (short notice, I did not think I could get this much done this soon)...nothing a handfull of Excedrin extra strength won't cure.

Rod

 

[evelrod]

OK...I finished the dyno runs yesterday and checked the compression and leak down. The compression ck was a little up and down (????) as it's usually even across the board...this time, with about two hours and three pulls on the dyno and the bigger cam, it's 225-240-235-230 after 8 turns and, later the leak down was barely readable on my guage...something less than 3% on all four cylinders. Also I picked up 13.25 hp and 4.86 ft/lb of torque extending the rpm range by 300 and not loosing anything below 5000 (the engine never sees any use below 5000 if I do my job right). I'll do further tests, of course, after the Laguna Seca race in Oct.

Soooo---it sure did not take long to run in, did it?
Oh yeah, I changed the oil from Castrol 20W-50 to Mobil 1 after the dyno runs. Surprising how much stuff comes out in such a short time even though I treat engine building like surgery!

Rod

 

[turbocohen]

While working as an intern at the buick plant 2 decades ago the routine involved sending the long block through a station where a booted manifold was servod against the heads and exh manifolds were pressed against the exh ports.
The starter was engaged (sparks flying) and baby takes first breath. Run time was under 2 minutes and involved a prelube run up. I think there was some sort trash rinse before the pan was installed but a lot of small metal trash, manufacturing residues, core sand and misc FOD. I visited a northstar plant recently and it was clean enough to eat off the floor let alone the engine assembly.