DoubleNutz

Did a search and can't narrow this down. Can anybody point me to the engine break-in procedure for a rebuilt engine?

Dave Howerdel

Pat
A bit vague but how's this http://members.rennlist.com/pirtle/87man12.htm

SharkSkin

Interesting article on this subject here. May be a bit controversial, but what he's saying makes a lot of sense to me...

Brent 89-GT

You need to build cylinder pressure to seat the rings. That means you must put a decent load on the engine. Camshaft break-in is generally first though, 20 mintues at 2000 rpm steady. If it is successful, ie running correctly, you are ready to drive.

One method I have used with seeming success is to run rpm ranges. Full throttle from 2000-4000 and coast back down to 2000, back to full throttle. Hold the gear so the engine brakes itself. Repeat several times then change the range to 3000-5000, then 4000-6000. If you can find a long grade to pull this helps put more load on. If you want it to be fast, run it hard right away.

Gretch

Pat, drive it as if it were a rental.......always worked for me.....

DoubleNutz

I thought that the advice you guys are giving me is correct. It is not for me, it is for a friend who swears that running below 4000 rpm for the first 2500 miles is the proper way for breaking in these engines. I have tried to convince him that he is going to jack up the engine doing that, but he is convinced that his Chevy buddies know more about 928 engines than we do.

I know that Mark Thomas offered similar advice to each of yours but this guy is so clueless he does not even think Marks word is credible. I think I am going to refer him to this thread and if he still decides that below 4000 RPM for 2500 miles is the proper way for his engine... oh well then I guess that's another 928 that will need to be flagged for the future so that when he trashes it and decides to sell it...we will all know better.

atb

Pat, sent you a P.M.

rixter

bring her to me.. I'll break her in real good

Brent 89-GT

Funny thing is, the advice I gave applies to domestic V8's. It is the advice of a Corvette engineer, and my Buick engine builder. It applies to every racing engine I have ever heard of. Does he think that drag racers nurse those things around for 2500 miles under 4000 rpm?

My big block Buick was broken in on a dyno. 20 mins of cam break in followed by a dozen full load, full rpm pulls. Doesn't burn a drop of oil, makes 525hp. Whoever he is talking to needs some schooling, but of course, it is his engine. With that procdure though it will likely be a weak oil burning lump.

Fastest928

I am changing my procedure and now are convinced that no one process
is right, so I now just run the engine at 2000 rpm for about 10 -20
minutes, then up and down the rev range, then onto the dyno for full throttle runs up to 4000, 5000, 6000 and redline.

We use non deterbgent dino oil for the first oil change.

Factory 928 engines were dyno immediately after a warm up period to check ofr proper operation and leaks, and then held at peak torque and peak hp for 1- -20 or so minutes each.

Since we leakdown test every engine at both partial assy, without heads on, and after assembly, we find that the hand turning of the engine is good for a 97-98% sel at 100 psi. if the cylinder is prepped properly.

Abby Normal

I've told this similar story as evidence a hundred times, and in fact have even posted it here.

Warm it up, drive it 20 minutes, and then red line it through every gear....

Abby Normal

Is there an engine only dyno anywhere for a 928?

Jim bailey - 928 International

The 928 owners manual and service warranty manual the only thing it says is change the oil after 1,000 miles and check for leaks... And that is for a new 78 model with a new engine. I will guarantee that the new engine had very few "miles" before it was stuck in a new car. For cold engines always they want you to start and DRIVE moderately and not let the engine idle to "warm up". Based on Doug Hillary's extensive oil analysis and engine operating observations it takes maybe 15 minutes of driving or so before it is ready to rumble.

Mongo

maybe Porsche NA can disclose it's engine break in procedures for the 928.

The link with the guy mentioning dynoing the car and some full throttle runs does have a good point when it comes to the piston rings. On the other hand, it sounds like something you would do to a brand new GT3

Jim bailey - 928 International

I think Kelly-Moss adapted their engine dyno to hold a 928 engine other than that Porsche had them at the factory ... everyone else simply dynos them after they are in the car.