Running-in a built engine
 

What's the recommended procedure for oil changes on a newly-built engine with Darton sleeves? Darton recommend using running-in oil until 5k miles although max revs can be used from 1k miles. Has anyone with experience followed this procedure and continued to use mineral oil for the first 5k miles?

This is a potential very large topic. But I will start with questions ,

What is the spec / Mod level of the car and its intended use / power level ?
Do you know the ring clearances / build tolerances of your engine ?

I can assure you running a Subaru engine for 5k miles on mineral oil your big end bearings will be scrap, its 2019 not 1958, materials, tolerences etc have moved on.

Hi

I would use the Millers CRO 10w-40, then change it at about 30 miles, 250 miles and then 6-700 miles. That's a mineral oil and it will have run the engine in by then, in fact it was probably run in long before 700 miles, but it's worth being sure after the expense of a rebuilt.

I have no idea why some companies recommend such long running in periods, too long and it goes from running in to accelerated wear.

If you look at track cars that are not road legal, they don't have a chance of long running in periods, just a blast on a dyno.

Cheers

Tim

always used the same process for my multiple engines,

500miles on mineral oil, no boost (well waste gate pressure as actuator is disconnected), 3.5k rpm rev limit.
oil change to semi, 500miles 3.5k rpm rev limit, no boost
oil change to fully synthetic, reconnect waste gate, remap to full revs and boost

always turned out to be a great combo, i've had multiple forged 2.5's, my dads had 2 2.0's and non of them have used oil or ever missed a beat.

Thanks all for the feedback. This is actually not a Subaru engine but a built BMW S62 V8. I thought I'd post up here for advice given how many people in the Subaru community have experience of built engines.

According to Darton's own website: We also recommend you do not run synthetic oil until at least 5000 miles. Synthetics work so well that the engine will never break in properly if it is used too soon.

dam, thats gonna be a bit of a beast by the sounds of it, what power is the target?

800 bhp supercharged

Arrow rods
CP Pistons
LA sleeves (not Darton but struggling to find LA procedure, assume sleeves are pretty similar)
Standard BMW bearings for mains
Calico for crank bearings
Stud kits for head and crank

whats it going in?

get some pics up!!!! haha

As I thought it was a Subaru, I mentioned the CRO, but with the S62, you want something a bit thicker, like the Fuchs Superma 15w-50

https://www.opieoils.co.uk/p-69400-f...ngine-oil.aspx

If it's run in on a mineral oil, it will be run in long before 5000 miles, it should be far less than 1000 miles. After that the mineral based oil will just be giving less protection than a synthetic.

Cheers

Tim

To back up the questions, ( But not with Darton competition Sleeves )

I have a EJ207 Semi closed deck which uses a 2.0 Nitride Crank , Mahle Pistons 93mm (+1mm) Manley Rods , ARP bolts, Race ACL bearings
new 11mm Oil pump and the supporting Mods for the SC360 Turbo, 350 Ft Lbs / 350-360 Bhp peak power at 6500rpm on 102 octane New Radiator core , oil cooler Std for a WRX MY05
During final assembly I controlled /adjusted the 1st and 2nd ring gaps to the recommended gaps stated by Mahle Technical officer for a "Turbo of 350bhp" Mahle Product code 930020362 SUB28766112
use Gap clearance factor of @ 92 mm /25.4 x 0.007 = 0.25354 x 25,4 = 0.6439 mm That's 25 thou, This is a ring clearance is significant and larger than Std WRX pistons

For a running in procedure , on first start I did flush the re-build with a Mineral oil Castrol GTX 15-40 ,
to begin with just bringing the whole engine up-to the point when the fan kicks in ( oil around 80°C ) .
Setting the rings after a 20 min period with 30 seconds each at 3000 , 4000 , 5000 , 6000 rpm.
leave to idle and cool.

Then fully drain sump and clean the magnetic sump plug , use a new oil filter , refill with a synthetic oil 0W-30

Driving the car 300 miles, driving with low boost ( as far as possible not higher than 0,5 bar )
but generally using the range of revs 2500-5000 rpm. Occasional short use of 6000 rpm but kept in low gear so never under load.

1st Oil change / filter with fully warm motor Drain Sump / clean magnet plug observe for fine steel particles , add full synthetic depending
on season like Castrol edge 0W-30 5W-30 ,

In the next period 300-1500 miles start to gradually give the engine more load for short periods of time ,
and watch for any significant oil / water temperature changes. Back off if you see quick rises of 15-20 degrees.
at this point I consider the Forged engine to be ready for higher loads and again depending on ambient or type of use
to move to a Full Synthetic at 10 or 15W-40 or even 10- 50 in my case I use Motoul ESTER Core when at track.

Probably moving back to a 0W or 5W-30 as when the winter approaches.

Not mine, but a mate's E39 M5.

https://cimg7.ibsrv.net/gimg/www.sco...910041ed98.jpg
https://cimg8.ibsrv.net/gimg/www.sco...e6f70d4bae.jpg

that literature is NOT talking about running-in for 5000miles but simply not using a full synth oil until you have completed 5000miles...............

don't agree with that either but that their perogative

Exactly Alyn. They are recommending using mineral until 5k miles. Of course you still need to change the oil well before that.

30 steady miles on the dyno, oil change, back on the dyno, full tilt maximum boost.
Mapping over, off to the hillclimb

the best and most reliable engine I ever had was run in like this.
old engine failed at croft on the Saturday, parts ordered from Alyn on the Monday, machining done Tuesday, engine was built on Wednesday, fitted Thursday, mapped Friday. Took it to mlr 22b croft sprint on the Saturday and did a class win.
That engine was literally through together and lasted 3 years of extremely hard use.
I

Thanks again everyone for the feedback. Glad to see familiar names and great knowledge still residing in these parts :)