Hey guys, my ef is currently getting a au freshly rebuilt motor put in (rebuilt by myself)

just wondering how i should go about running it in? some say go hard some say leave it for 1000km's then go for it?

basically what i was thinking, fill it with running in oil..run for 400 or so km's then put more running in oil for another 500 or so km's, then go fully synthetic mobile one 5w30..does this sound ok? during the running in oil km's i was thinking of limiting myself to about 3-3500rpm until after the 900km mark?
how long before i can race and so on?

Load it right up at various speeds, and back off and load up again.

Dump the oil after 20 kms or so. Then vary speed and throttle for a bit. I have done 750 kms in mine. Drive it like normal. Basically you go hard, otherwise how can the rings and bearings bed in???

Cheers

Daz

Why put a full synthetic oil in it.......you gonna race it...a lot...take it to 6,500 rpm on every gear change??????....a waste of money.
A semi-syn oil is plenty for an everyday driver. Don't run coolant/inhibitor in it for about 2 weeks, so it can have a few heat/cool down cycles....lets the head gasket bond to the block and head.
Also good idea to run a radiator sock to catch any crud that may loosen up from the block.
Only have the radiator cap on 1st notch......keeps cooling system pressure down a bit for the gasket bonding thing.

I see you have another post about running in problems. I read through a few different methods and settled on Puma Race Engines method.

1. Install new oil filter & Running In oil. Run engine in garage/driveway for 15 mins at 2500rpm to break in new cam (if using one). Otherwise, this is a test for oil & water leaks and to flush assembly lube. Good to have someone watching for oil & water leaks while doing this.

2. Drain oil, replace oil filter & fill up again with Running In oil. Take your car out to a straight quiet section of road (like a back road). In 2nd or 3rd gear, power up hard from 2000 to 5000rpm, foot off accelerator and let the engine throttle down by itself to 2000rpm. Repeat this about 10 times to bed in the rings. You only have about 20km to get this right before the bores start to glaze. If the bores glaze before the rings seal, then you start using oil.

Fifteen years ago, I rebuilt a 2.6L Astron engine and drove it like a granny to run it in. The result was it used 1L motor oil every 100km.

3. Drain oil, replace oil & filter again. 90% of your engine break in is now complete. I used Running In oil and varied the revs for another 2000km, but 1000km is probably enough. It's quite thin oil and I didn't like watching the oil pressure drop to almost zero when crawling in city traffic.

4. Drain oil, replace filter & fill with your preferred regular motor oil. I opted for the Nulon Street & Track HP oil (15w50) after speaking with one of the guys at Autobarn.

This method worked for me and I've had no problems with oil use since then.

Thats pretty much the method i use. Though i use diesel oil with a high zinc content and a bottle crane break-in fluid.