Hello. So over the summer Manolis_D and I rebuilt my engine in my '91 NA (turbo intermediate housing, new turbo rotor housings, 2pc seals, same high comp rotors, new bearings), and at this point I have about 1300 miles on the engine. While running it for those 1300 miles, I kept it below 4000 rpm and never really went down to full throttle save maybe once or twice. So I have been relatively sparing with it.... but I was wondering if I SHOULD give it some high RPM operation (higher than 4000 at least) at some point for whatever reason?

That is, I am asking if in the course of breaking an engine in, should I avoid being TOO sparing, and edge it up to 5 or 6K a few times?

 

I was just reading MazdaComp's catalog that I have last night about this. They say that when rebuilding the engine you keep it under 4000 for the first 100, then sparingly bring it up to 6000 for the next 100 and then only redline it a couple times until you hit 300 miles. After that change the oil and you are done.

If you have 1300 on it already you should be well broken in.

If anyone has other opinions that's cool because I am only going off of the MazdaComp catalog.

 

Break in period is until 2500 miles if my memory serves me right.

But you should run it hard a few times and drive it normally by now.

 

Way we (Pineapple Racing) allways broke engines in was under 4k rpms for the first 500 miles, then for each additional 100 miles, you could take it anouther 1k rpms. Sounds like the motor is broken in to me. Might want to check with you motor builder though, just to make shure. CJ

 

My motor builder was me, so I can't really check with him
So I hear alot of "can" 's and all those guidelines were helpful when I first got it running BUT what I'm really wondering is: is "necceasry" to do so to run an engine in "properly"?

Thanks,
Andrew Pullin

 

I've just had my FC Turbo motor rebuilt and haven't started it yet, and the instructions he gave me were as follows: no more than 3000rpm for the 1st 500km and then no more than 4000rpm for the next 500km then change the oil and oil filter and your done.. If you've done 1300 Miles, yours is ready to go, I'd give it some stick and enjoy it