Break In

[Liquid Asset]

My mechanic and I were looking throug the detroit manual for the break in procedure and can not find it. Does anyone have a Detroit manual with the break in procedure, and if so, what is it?

 

[krush]

"break in" is one of those opinion things. Back in the old days it used to be run it hard to seat the rings. Then people got into this "take it easy" deal.

Well, now most people (after extensive dyno comparison) agree that running it hard to get high cylinder pressures to seat the rings before glazign occurs on the cylinder walls is the best way. The airplane guys have known this for years and they actually state you can see a new engine's cylinder head temps (aircooled) drop and oil consumption go down once the rings seat.

This guy sums it up with PROOF. http://www.mototuneusa.com/break_in_secrets.htm


Of course, expect lots of opinions (I just gave mine).

 

[captddis]

I am with Krush, Don't baby it keep it at cruise as much as possible for the first 15 to 20 hours. When Cat comes for a start up and seatrial, they want 2 hours @ WOT! Used to run the new boats down at 2200, never had a smoker or oil burner!

 

[MikeP]

Here's a typical "break in" as we performed them for car engines on a dyno. You can do the same thing on the road or strip. This is the procedure we used for all engines, regardless of their final intended use (street or competition). (Might be interesting to know that beginning around 1978, we used syn Mobil 1 oil in all engines from the moment they were re-assembled including "break-in.")

Engine warmed up to operating temp then:

1. first pull - WOT from idle to 1/3 max RPM - throttle off with dyno load maintained (in gear on the road) back to 1000RPM.
1000 RPM for 2 minutes
2. second pull - WOT from idle to 1/2 Max RPM back down same thing...
1000 RPM for 2 minutes
3. third pull - WOT from idle to 2/3 Max RPM same
1000 RPM for 2 minutes
4 fourth pull - WOT from idle to 3/4 Max RPM same
1000 RPM for 2 minutes
5. fifth pull - WOT from idle to Max RPM same thing

That's it, engine is broken in. - nothing else is necessary and car can be operated however you want it to be operated from that point on.

This procedure ensures that the rings/cyl walls are properly seated for max power, long life, and minimal oil consumption, which is the only item that actually needs "break in." Should work exactly the same for a diesel but since I never did it on a diesel, I can't speak from any experience.

But I'll bet it will!

 

[krush]

(Might be interesting to know that beginning around 1978, we used syn Mobil 1 oil in all engines from the moment they were re-assembled including "break-in.")

That is interesting. Most people argue that use strait dino stuff to allow a little bit of friction because the synthetic is just "too damn good" to allow the rings to seat. It's all hangar talk unless somebody has actually done documented tests and I bet it really doesn't matter as long as you beat it for the first hour or two.

 

[Genesis]

I concur. Getting the rings seated is important and results in better engine life, less blowby and less oil consumption.

Screw this "baby it" nonsense. You run for a few hours at the dock on a new build you're asking for glazed cylinders and poor oil control.

Never put the wood to a cold engine; allow it to come up to temperature first. Diesels won't do that at idle without a load, so once off the cold peg, come out of the marina (you should be off the cold pegs by then) and then take it to 900 RPM or so until you're at the bottom of the normal temperature range, then go ahead and run 'er up.

If you're doing this "in the boat" then my procedure is to come to operating temperature (as I do normally in any circumstance) and then run it up to 1500 RPM, hold for 2-3 minutes, then back to 1000 RPM or so. Hold for 3-5 minutes, then repeat at 100 RPM intervals, all in gear. Last run is to WOT, then back down.

Then take the engine to normal cruise RPM and let it run for a good solid hour.

If you have cylinder head temp or EGT gauges you'll see them come down some, usually during that first "real" hour of operation; that's how you know the rings are seated.

If the engine wasn't built right you may as well find out straight up. If it is, there's nothing other than the rings that need seating or "running in."

You want to get it good and hot and get the combustion chamber pressures up so that the rings are properly seated.

A LOT of damage is done to engines by babying them in the belief that they need it when "new". Nonsense. All that does is glaze the cylinder walls. My Jetta was driven like I stole it from the day I bought it and at 80,000 miles it consumes less than 1/2 quart of oil between changes on 5,000 mile intervals, with all wear metals coming back well within tolerance.

BTW on every vehicle I've owned "new" in the last 15 years I've ran Mobil 1 since new, including my Yamaha 4-stroke outboards. None consume any material amount of oil. There's no need for the "extra friction" if you get the combustion chambers good and hot and the pressures up right from the outset.

 

[fixin-to-cruise]

Section 13.2.1 of my DD V-71 manual has "Engine Run-In Instructions". They are 7 pages long. DD says "the engine should be Run-In on a dynamometer prior to release from service" and are approximately this; idle for 5 minutes and then shut down and inspect, 40% power for 30 minutes, 65% power for 30 minutes. I can fax or mail you copies of the pages if you send a PM.

I'd be inclined to do the dyno run-in schedule underway. Break-in is not covered in the manual. I've broken in a few airplane and outboard engines using limited but increasing rpm's for the first 10 hours or so and frequent oil changes. A DD tech person might have some info that would help.