I'm doing a rebuild on a motor that was rebuilt and had a coolant seal failure after only 3K mi. (see my prev. thread 'bad rebuild?'

The intermediate housing needed replacing and was replaced with a newly resurfaced housing. All the soft seals and orings are being replaced but side seals, apex seals, bearings, thrust washers, and oil control rings will be reused. The rotor housings were new when the first rebuild was done and all the seals and rotors were tracked and will be replaced back in the same locations as the first rebuild.

So my question is, what kind of break-in do I need to do, if any?

I would say a 500mile break in, just to reseat the seals would be suffient.

yeah, thanks exactly what I was thinking -

zero boost and minimal revs to 500mi. then tuning from there

yeah 500 miles is good. i wouldnt worry about not boosting it, just be easy on it

u missing the most needed thing!! the side seals is what keeps most of the compression in the motor.



please dont ask how i know that !! lol

I thought I mentioned I am reusing the side seals in my post?

I wouldnt worry about it too much. Just drive the car around for a bit to make sure everything is good to go.

If you measured clearence on everything like in the shop manual what is the point of a break in?

Breakins are for those who dont measure anything https://www.nopistons.com/forums/pub...DIR

Before taking my motors past 20 psi, I have made a point of breaking them in for at least 700 or 800 inches...Its about that far from my garage to the first stop sign..

hell yeah mein