Running-in oil

[Poodle]

Had a good browse on the interwebz, but am hoping some on here have some personal experience to impart. Having just rebuilt my engine i'm aware it will need running in properly, what are people's opinions on how best to do this? Is it even that crucial or is it another hyped-up, common knowledge myth?

As i understand it i will need mineral-based running-in oil to ensure the new rings bed in properly and to do the first ~20miles immediately on first start up. There seems to be a lot of differing opinion on what to do with boosted engines during this first 20 miles, whether it's to drive them as normal or avoid getting on boost during this period, what with mine being rather more boosted than most i'm particularly interested to hear what you folks have to say on the score.

[bashbarnard]

Every engine I've built for myself. Grand total of 2. I've stuck some cheapy mineral oil in like 5-30 tescos own crap. Done 300 miles carefully then drained the oil filled up with correct stuff and off you go.

Also I've fitted a fair few pd recon engines as the later ones throw rods. The company who supplies them specifies 400 mile run in on standard oil drain refill off you go. New filter as well obviously

[darrenjlobb]

Run it in pretty hard, but in short bursts, and dont scream the daylights out of it (wont be able to anyway unless a mapper has learnt what 6000rpm + is yet!)

Just put some generic oil in it, and dump it after first few drives, then do another few hundred, and then your good to go with decent oil...

Obviously that is my view, but I always run motors in hard, Or else you will forever more have bad ring seal / blowby.

[bashbarnard]

I think this is going to turn into a opinion poll rather than a what to do thread. Lol. Funny though it does seem to differ on the driving rather than the oil draining as much.

[darrenjlobb]

Thing is you have to remember, modern engines (yes even xud/dw10 i would consider modern) have very fine tolerances from new / rebuilt, they simply dont require "bedding in" to the degree that old motors did, You used to literally end up with oil full of metal / bearing contaminants...you wont get this with these motors, or if you did, you have done something very wrong...

The way I see it is when you hone the bores out, its essential the rings are pushed out against this hard to allow them to "bed in", if they dont, they bores will smooth out and they will never bed in well, and who wants to rebuild a motor and have it breathe heavy for ever more..

I dont mean hold it on full bore for long periods / take it for a chronic hoon where the motor is under CONSTANT stress, but give it lots of bursts of boost / power to aid things.

Driving it like a "granny" under 3krpm for the first 500 miles is a recipe for disaster IMO however what alot of people will state is the correct way of doing things.

My old XUD used to run 60psi of boost, but you could put a sheet of paper over the oil filler at idle, and that was given a hard run in just like my other motors have.

[shervo]

I agree with darren. Run it in like you would a two stroke engine, drive it like you intend to drive it minus abit haha so run it in pretty hard. I think everyone will agree on the generic oil then drain it after a few drives.

[Ruan]

You MUST get some power down if you want the rings to seal...

The key is remembering that whilst yes you want some power behind the rings, you mustn't allow it to get hot, because things will be "tight", you want to allow the power, but don't just sit holding it on boost for 10 mins, things will get very hot, very quickly and damage components... Nor do you want to sit on the motorway at a constant speed, it won't bed the rings in, and you've only got one chance to do it... Once the bores are all glazed up, you're stuffed!

For the first 10 minutes, obviously allow it to idle and give it a few revs etc, top up coolant etc... Take for a very quick drive, very short squirts of power to allow oil to warm, drop the oil. Stick some new stuff in, go out, drive about, allow a bit of power, probably let this oil last for a few drives, then drop it. Then put in some decent stuff and really start building the power for longer periods, once you think you're happy with it and you think it's reasonably bedded in, drop again and start whatever service intervals you're thinking of.

Don't use the cheapest crappest oil money can buy whilst running in, just some usual semi 10/40 5/40 will be fine.

[Paul_13]

http://forum.205gtidrivers.com/index.php...omsearch=1

[Dum-Dum]

I agree with darren on the bedding in.

IIRC halfords do mineral oil in a roughly suitable grade. drop that out after 30-50miles then run something else cheap ish for another 500ish before swapping to your decent oil IMO

[Niall]

With regards to running in oil, its pretty conclusive that you just use mineral oil. I won't go through my running in because we all know i didn't torque a main bearing cap and destroyed my big ends but oil wise, i used a mineral oil for 200 miles then went onto semi synth for mapping and changed it right after mapping.
The running in procedure...Tbh i spent several evenings trawling the net and a few old books on this and there isn't really a conclusive answer. A lot of people seem to say its dependant on how you wish to use the engine. Like, if its a race engine, run it in fairly hard as that is how it will be treated for its life. Thats all well and good but we all know race engines won't last as long as a engine built for the road...but then thats a cost you accept when getting into track days or racing!
Personally, i went with the method Darren suggested. My car is road use and does get driven like my nan drives sometimes so i ran it in relatively hard, short sharp amounts of power and stuck below 3000rpm for the first 100 miles then gradually opened it up.