How much miles for break-in period?
 

How much miles and at what boost levels shuold I break the engine in

Street port single turbo upgrade

Some will say that you don't need any break in, others will say you should take it easy for ~500 mi. If you asked me, the only advice I could give you would be to NOT break it in with steady state, low-rpm cruising.If you decide on a break in period, make sure to run te car through the gears, but try to stay off the boost (less stress).

first 500 miles, take it easy (no boost) do not exceed 3700 RPM then the change oil: Next 500-700 miles, take it easy, gradually increase load and RPM till a 5500 RPM limit and low boost, then change the oil: For the next 500 miles gradually add load more and more and higher the RPMs till you've reach full boost and full rpm, should be well broken in now and change the oil after 2000 miles. This is what I've been told time and time again by different engine builders and what I've done with all fresh engines. It requires some dissaplan, but the piece of mind of doing it right is worth it to me IMO.

~Mike.....

No need to break it in. You can turn the boost up to 25psi and your motor will be fine.

Ah yes, that would be the "blithering idiot" faction. I know them well. :)

This is more or less the standard fare for a street engine, well, maybe it's a bit more. I think most engines will be OK with just 500mi 4000rpm and less, followed by 500mi of increasing rpm and load. You don't need quite as long of a break-in period if you are still using the old bearings.

The oil is also important. Start with 20W or 30W low-ash mineral oil. After the break-in period you can switch to your usual mineral or synthetic oil.

More useful tips from Racing Beat:
Prime the new engine by removing the spark plugs and cranking the engine over until you get an oil pressure reading. Then reinstall the spark plugs and start the engine. Run it at high idle for 15-30 min while checking for fluid leaks or other problems. (Evil Aviator notes: 1) it is best to have a friend help with this, 2) have a large shop fan blow on your radiator while the engine is at fast idle so you don't fry your new engine).

i've always heard

every new motor: let it idle for 30 minutes or so checking for leaks

if new rotor housings and seals - after idling let it cool down and then go drive it around through the gears for a few minutes not getting on it....maybe 15-30 minutes....and then go race.

if old housings & new seals -going to take more time to form a good seal so after idling & check for leaks, let it cool down and then take it easy for 500 miles or so under 3000 rpm and no boost and then the next 500 miles start increasing RPM and boost.

The last motor i broke in i took it around town staying below about 4k rpm and no boost for around 4-500 miles (had no working odometer). Then I got into a few psi for about 200 miles and then drove it 750 miles to Dallas getting into about 5 psi boost here and there and higher RPMs and had pretty good compression on my motor.

OH - and in any case whether after 500 miles or after first race change oil. I used 10W30 on break-in period. Now use 20W50 on street & track.

maybe those who have been through a few motors and making good compression on all of them can comment.

is this a mazda reman or was it rebuilt?? because I belive that they spin the remans to 10,000 rpm's before shipping them :) you would really only worry about the cooling system I would think

Correct, the remans are already ran and tested for leaks prior to shipping. No need for break in. When you purchased the cars new, it said no where in the owners manual not to boost the car till 500 miles. THis is BS. This has been asked many times. No need to break in slabs of steel! Not saying you should run 30lbs of boost, although I've seen a brand new motor started and broken in on the dyno running 30lbs of boost with no ill effects. Use your good judgement, but after a few heat cycles your wasting your time.