Where can I find engine break-in procedures?
 

I had a 3.0 rebuilt and the wrench is shipping it next week. I ask him if there was any "break-in oil" that I should use, and is there any "break-in procedures” that I should follow.

He said just use whatever oil I was planning on using and to pull the spark plugs and pour about a "shot glass" of oil into each cylinder. Turn the motor over via the flywheel a few times, replace the plugs, install the engine into the car and drive it. He said not to redline it or drive it hard until after about 500 miles.

Where can I find "break-in procedures" for this motor? I did a search on this BBS, the only thing I found was to prefill the pump before starting the engine. What pump are they talking about?

I just spent a lot of money to have this motor built right, and I don’t want to leave any stone unturned. I don’t want to overlook something and be the cause of a catastrophic failure.

p.s.- He did not start the motor after he rebuilt it, he said that when he sets the cams, thats the same as starting it . and he knows it will start with no problem. Is it normal for a wrench to build a motor and release it with out starting it?

Thanks
Rick
1977 911s
3.0

SmileWavy

I had the same question a while back, this link should help

http://forums.pelicanparts.com/porsche-911-technical-forum/82222-engine-rebuild-break-after-200-miles.html

I disagree with the "shot glass of oil into each cylinder" technique.

You want the cylinders and pistons with nothing more than a thin film of lubrication on them for the initial start-up. This will help insure the rings will seat quickly. I do this with the m/c engines I have rebuilt, and have never had a problem with the rings seating.

You should buy my book - the last chapter is dedicated to this...

-Wayne

I use a non-detergent 30W oil and drive it hard enough to load the rings. Whatever you do, don't let it idle very long.
-Chris

This topic can verge on the religious, so be prepared for some very different ideas.

Here's what a local 30 year Porsche engine builder prescribes:

- Light weight dino oil - 10 weight for breakin
- never more than 30/40% throttle, NEVER lug it below 3000
- limit revs to 3500 for 100 miles, 4000 for 100 miles, 4500 for 100 miles, 5000 for 100 miles, no limit for 100 but be sensible.
- change oil and filter [regular 10W50 multigrade dino], check drain plug magnet carefully. Reset valves, check thoroughly for leaks.

The rings seat very quickly. Most of this rev limiting regime is to protect the rod and main bearings while they are seating. This method works, and has been proven over many Porsche engines. YMMV.

this site was posted recently


http://www.mototuneusa.com/break_in_secrets.htm

Non- detergent oil for the first oil change or two. No shot glasses of oil, especially if the builder wiped a little oil on the cylinder walls during assembly as he should have. Limit revs. change oil after 500 miles.

Drive the car. Don't let it idle. Once it is started, take it for a spin. Be nice to it, but you can use more than 40% throttle.

This all sound great, but what do you guys think the factory used to do to those early 2.0 to 3.2 motors? Didn`t they check them on a dyno, set them up and then insure they made the rated power? I am sure they saw close the max rpm. Dont be afraid to use it....within reason.

As stated previously, you need to put some pressure on the rings to get them to seat. Vary the rpm, don`t lug it and keep it out of the redline for the first several hundred miles. Then change the oil check the valves and head torque and your good to go.

Tinker

Since no 2 or 3 "experts" seem to agree on this, I am going to follow the Motoman theory, (link posted by RoninLB), at least he has some logical science behind his technique and claims proof from torn-down MC motors. I am re-using Alusil P/Cs, (w/ new rings), I need all the luck and technique I can get.

It is true that the factory drove every car balls-out right off of the assembly line, (on the test track), and Porsche has never had a recomended break-in procedure for the 911, or special oil, etc. Don't believe me? Read your owner's manual- it won't be there. Still, Motoman's technique makes sense, can't hurt, and might make for a tighter sealing, faster motor. He gets my vote. :cool:

P.S: Pay special attention to what he says about idling/revving in the garage, (big no-no), just get it up to operating temp and blast it up/down.

The factory used to do a one-hour break-in and power test run after warming up on a dyno for each engine built! Only after satisfactory results would the engines be installed in a car. Timing was set at 6000 rpm after warm-up, and the run-in included specific loads on the engine at specific rpms ... for ten minutes each, up to 6000 rpm. The entire dyno run took more than an hour because of the warm-up and ignition-setting steps.

Straight SAE 30 oil that was recommended in the owners manual was used ... rating was MS ... 'M' was SAE spec for ignition-type gasoline engines, 'S' was SAE spec for 'severe' or best available grade at the time ... this was a detergent oil of the best grade of Shell motor oil at the time!

Well, there you have it. I always had a feeling that the factory did the breaking-in for us, just wasn't sure if it was on the dyno or on the track. Bottom line is that Motoman is right, it pretty much occurs, (or doesn't), in the very first hour/miles of a new set of rings. Also, the break-in procedure emphasis is on seating the rings, not "fitting" the bearings and moving parts to one another, they are supposed to fit very precisely from the get-go. He goes as far as recommending to drain synth oil from new motor, put in ND dino for break-in exercise, then switch it back to synth, (if that is recommended lube). Says that proper ring seating makes the difference in oil consumption, power, longevity, (less contaminants past rings into oil), for the service life of motor. Makes sense to me. :cool:

Bump looking to see if anyone has any extra info on this.