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x98boardwell x98boardwell is offline
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Join Date: Sep 2006
Location: Central Valley, CA
Posts: 1,529
How to break in rings on an 87-930... what do the experts say?

FYI: Also listed on the Engine Rebuilding Forum.

I own an 87-930 and recently did a top-end job including honing the cylinders and installing a new ring set. I did not touch the case in anyway during this top end other than installing new master link chains and ramps.

Here is the link from the build with pic's. Updates on engine top-end rebuild

I have heard a few things and am curious on what the experts think. I use the word experts because I would like feedback from the guys who have seen this in the real world... not someone who heard it from a buddy.

1) I was told to go easy for 1,000 miles with no boost.
2) Go easy for 1,000 miles and introduce boost occasionally (around 1 - 2 10ths bar) to help seat the rings with higher pressure.
3) start driving like normal... the boost will actually help seat the rings by forcing them to push against the cylinders under load... my buddy told me this, hence the reason for this thread.

I am using normal (non synthetic 20/50) oil for the first 1,000 miles and plan on changing once around 200 to make sure there are no metal chunks that I need to know about. Also, I realize that my car is a relatively low compression motor around 7:1 or 7.2:1 or something around there. I am guessing that when boost is introduced the compression rises to around 10 or 11. Now, an SC motor is around 9 or 10:1 and their compression is always that high. So, whats the difference if it is compression from boost or from the pistons normaly?

Lastly, when people purchased these cars back in the 80's the dealer or Porsche did not tell them to "baby" the car for the first 1,000 miles did they? I bet they left the lot sideways if they had LSD. This is what may have lead to short engine life but I am trying to figure out what is best based on experience.

Your input is appreciated.

Old 01-26-2009, 11:51 AM
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