My engine was rebuilt about 620miles ago. It hasent been taken onver 5K so far tho it has been boosted to about 5psi. My question is when can i start to take it out to the redline and when can i run full boost?
Thankx

 

Here's a good discussion on that topic. Everyone's gonna give you a different answer:
https://www.rx7club.com/forum/showth...ebuild+breakin

 

thanx

 

Tear it up.

 

man, for the first thousand miles I kept mine below 3k most of the time and below 3500 all the time and never let it go under boost. Hope you broke it in OK!

 

Skip at KD Rotary recommended the following for my rebuilt engine:
-Under 4k for the first 500 miles, then change the oil
-Under 4k for the next 500 miles. Change oil again
-Under 4k for the next 1000 miles, touching maybe 3psi of boost, but only once every couple days. Change oil at the 2000 mile mark, and you can beat the hell out of it.

I did it. I figured it couldn't hurt, and I really didn't wanna go through the rebuild process anytime soon again.

 

That seems excessive since Mazda's recommendation for brand new motors was 500 miles under 4000 rpm. Rebuilt motors with used parts should theoretically require less break-in time.

I think 500 miles of 5 psi boosting below 4k rpm is just fine. I would spend the next 500 miles working my way up to redline and full secondary boost.

But what do I know, I'm still on my original engine....

 

The original motors don't have all of the gunk the rebuilds do.

 

I am just in the process of running in my new engine.

I have been told the following:

First 500 miles below 3500rpm with zero boost
Oil Change - doing this tonight!!!
Next 500 miles slowly building the rpm up the the redline, with little or no boost
Not advised, but I will do another oil change at this point
Then slowly building up the bost over the next 1000 miles

This he said has proven to give strong engines in the past.

Dan

 

just curious how are you taking it to such high RPMs without hitting any notable boost levels? Boost controler?

 

Press the gas pedal slowly and watch a boost gauge if there is one.

 

I was told 500 miles no boost keep rpm's at 3000 or lower. Change oil
another 500-1000 miles varying rpms at low boost, change oil and then have at it after tuning.

 

Like what exactly?

 

That's just what I was told. When an engine is rebuilt all of the sealing chemicals, and temporary lubricants have to be burned away.

How many miles are you at Mahjik?

 

Huh?? Sure, the assembly lube will burn away, in like the first 10 to 15 minutes.

 

I did 1000 miles (mostly city) under 4000 rpm and no boost on my Malloy reman. Changed the oil at 500 and 1000 miles. With the fresh oil I promptly went out and lit that sucker up Strong as ever now with about 20K on the motor.

 

There really is nothing used on a rebuild that isn't used when the engine is first built. However, as with anything, it depends on who does the rebuild.

As mentioned, the lube that is used burns away, just as in a new motor.

As far as miles for me? I need to check, but I think I'm around 24k on my reman (which that's spread over about 5 years).

 

I don't claim to be a rebuild specialist in any way. It's just what one rotary mechanic told me.