Running an engine in

[maxfield]

How many miles would you say it is for a freshly built 2.5 S14?
Is 1000 enough?

[zaust]

gently for 1000 then oil change.

then gently for 3k oil change and your good for a hard 100k+

[Kos]

i'm guessing this id for your dads s14??

build it gradually, try not to go over 3500rpm for the first 1000 miles, then up it by 750rpm for the next 500miles to 4250, and again to 5000 rpm then a final 1000 not exceeding 6000 rpm then get the fucker mapped
do not hold it at very high rmp at any stage though, eg in the final 1000 miles don sit at 6000 rpm for too long, drive it up to 6000, and cruise around 5000, may be a bit more

seems a bit extream 3000 miles of running in, but when you spend lots of money on your engine you dont want it to fuck up on you.

there is no right way to run in an engine, just be sensible

[maxfield]

Thanks that should be good looks like it's all the way to spain at 3500rpm

[Turbo-Brown]

If it's not mapped then you're a bit buggered, as I was when mine was first started, because you can't safely apply full throttle.

However, if you're confident that the mapping's all correct, you should be looking to start it up, drive immediately to somewhere straight and quiet, and then full throttle accelerating from say 50-70 in 4th gear, then let the car decelerate using only engine braking still in 4th gear as this sucks oil up from the sump and onto the cylinder walls. Repeat this process a number of times.

This gives rise to some nice high cylinder pressures which in turn seats the rings properly. If you can't do this, the rings will never seat properly, will always leak more than they should and the engine will never make as much power as it potentially could.

You do it in a high gear so as not to let the revs run away.

EDIT> oh yeah, and for heaven's sake don't cruise to spain on a motorway at the same engine speed! You need constantly varying loads during the run in period!

[maxfield]

It will be mapped soon as the engines fitted.

[Demlotcrew]

If it's not mapped then you're a bit buggered, as I was when mine was first started, because you can't safely apply full throttle.

However, if you're confident that the mapping's all correct, you should be looking to start it up, drive immediately to somewhere straight and quiet, and then full throttle accelerating from say 50-70 in 4th gear, then let the car decelerate using only engine braking still in 4th gear as this sucks oil up from the sump and onto the cylinder walls. Repeat this process a number of times.

This gives rise to some nice high cylinder pressures which in turn seats the rings properly. If you can't do this, the rings will never seat properly, will always leak more than they should and the engine will never make as much power as it potentially could.

You do it in a high gear so as not to let the revs run away.

EDIT> oh yeah, and for heaven's sake don't cruise to spain on a motorway at the same engine speed! You need constantly varying loads during the run in period!

I was about to say the same! The only part in the engine that needs to 'run' in are the rings nothing else! In a M3 50-70 in fourth is about 4-4.5k rmp.

Andrew