How long must I wait?

[AW111]

I recently did a full rebuild of the engine in my MR2. It's a 1600 cc naturally apirated 4 cylinder.
I ran the rings in on the dyno, then changed the oil when I got home. Ran it for a week (about 250km), refitted the oil cooler and changed the oil again.

How much general running around do I need to do before I can -
1) Run it to redline (8,300 rpm) and regularly use WOT.
2) Change from running in oil (Penrite 15/40 mineral) to synthetic (I plan to use Penrite 5W/30 or 5W/40 full synthetic)

I am currently sticking to a self-imposed 6,000 or so rpm, but that's just where it really comes on song, and my right foot is getting itchy.

[AW111]

Mignon said:

http://www.pumaracing.co.uk/runin.htm

That's pretty well what I've done - I'm about 350 km into the final "change oil again at 1000 miles" stage.

I did the initial break in (cams & lifters were unchanged) on the dyno.
All runs in 4th gear with a cool down period between each set of three runs.
3 x 3500-4500 rpm, 1/3 throttle.
3 x 3000-5000 rpm, 1/2 throttle.
3 x 2500-5500 rpm 3/4 throttle.

It doesn't smoke, and uses no oil.

I am itching to see what difference the valves & head work have made, but that will wait for another 1000km or so.

[AW111]

stevieturbo said:

Many race or performance engines are run in on a dyno....in a matter of minutes, maybe hours at most.

Lets face it, it is rather impractical to run many for hundreds of miles easy to do it, as some may never even do that many miles in a year ! lol

While that is true, I hope this build will last another 100,000 km, while competition engines tend to be rebuilt every few years or less. They also tend to have bigger clearances.

On the subject of bearing clearance, OEM bearings are available in 5? sizes to suit different block / crank clearances, while aftermarket bearings come in standard and undersize only.

[AW111]

So the consensus appears to be that the job is now done and I can get on and enjoy driving.
I will change to synthetic in another 1000 km or so.

Thanks all.