I've just had a total new enging re-build.
My Mechanic, who has a very good reputation wants me to run it on millers running in oil for first 50 miles then change oil and filter, then replace it with the same oil. Then 300 miles off boost before changing the oil and filter, again with millers running in oil for a further 500 miles giving light boost. Then full synthetic race oil and full boost

I've heard this is way too much and may cause damage by glazing the bores and pistons??

Been told by another reputable Scooby mechanic to use millers running in for 50 miles then change to a semi-synthetic for 300 miles before changing to a full race synthetic oil, then job done.

Who is right?????????

 

Come on troops it's slipping away down the pages!

 

If you havent done any mods that could alter fueling whilst engine being rebuilt that could lead to overfueling and in turn possible bore wash i would say that for the first 1000 miles run it on a mineral oil with no more than 0.5 bar of boost and 4000rpm.
Change oil and filter but now switch to semi synthetic again keeping boost to around 0.5 bar, maybe increase the revs slightly (500rpm) with every couple of hundred miles. After another 1000 miles i would drive it as normal.
Change to fully synthetic after a couple of thousand miles on semi, all the while keeping an eye on oil level.

I personally would put some cheapo oil in for the first 50 miles and change it as your mechanic said, just to rid any possible contamination or small particles.

A lot of people are suggesting a more aggressive running in these days with more boost and revs, and some fully synthetic from the off which seems to work well.
I however like the more gentle method.

 

no it not slipping down the pages

 

My mechanic doesn't trust me, he's mapping it to run it in and said he will drop boost to only 0.5 anyway.

Have to say i agree soft and gentle sounds good to me! Sure my Mrs has said that to me before

Thanks for that

Anyone else want to share their opinion on the running in please say, i'm abit of a newbie

 

OHHHHHH - Now thats a whole can of worm's you've opened there
Every engine builder has their own opinions on the right running in procedure,
i tend to favour - no excessive loads or labouring the engine in a too higher gear for the first 200/300 miles,oil and filter change and then increase the loading on the engine in gentle stages after that.
Bore/Ring Glazing will ruin even the Best built engines
This makes good reading - It's motorcycle biased but apply's to all 4 stroke engines,turbocharged or not.

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

 

Come on folks! Roll up Roll up! Give your opinions please!

 

Right ... this the RIGHT way to do it ... Subaru themselves say so ...

Run in for 1000miles - keeping under 4000RPM but vary the loadings and speeds and Revs.

No fast getaways - no labouring the engine - be sensible.

At 1000miles - Oil change and Filter change ...... gently, over the next 500miles increase the pressure on the engine.

After 1500miles give it a good blast ..............

 

I had a bottom end rebuild and good oil was used from the outset. I drove below 3000 rpm for 1200 miles then changed to Silkolene Pro R and gently raised the peak revs over the next 1000 miles. In fact, I still haven't taken it beyond 7000 rpm (it's a classic STi) but there's no real need to. The car has been on a rolling road since the rebuild and in comparison to a RR graph from before the rebuild, it produces the same horsepower as before albeit with a smoother curve. The torque however is much stronger, peaks earlier and holds longer in a nice table top curve!

 

I agree with PSL's view, but if you have put your trust in this person to build your engine, does it not seem reasonable to also trust his judgement regarding the running in process?

 

Fair point "Old Fella".

Thankyou to Mr Lewis to, along with anyone else.

Just out of interest, Mr Lewis do you own a Scooby, rumour has it you have a Micra??

 

Hi

I recently ran in a fresh STI v6 engine (new block, teflon skirted pistons, metal gaskets) which was hand built from scratch (including porting and polishing heads etc.).

Engine builder filled the car with cheap mineral oil to seal everything up and advised me to keep off boost and below 4000 RPM for the first 1000 miles. Was advised to keep off main roads (avoiding steady speeds) and make sure the engine went through the revs a lot (so lots of changing gear and hilly roads).

I actually had a leaky injector o-ring after 100 miles, so the engine was flushed and inspected again at that point.

After 1000 miles, engine was flushed, car filled with mobil synthetic oil and started using 0.5 bar boost, 6000 RPM. After a couple hundred miles everything looked ok, car was taken back and custom remapped and the full 8000 RPM/1.6 bar was unleashed.

Seems the fairly standard way to do things.

 

This makes good reading, and is the way I ran in my bike engines. I never had any problems using this method. Have a read.. There is good logic there.. Honing and build quality is far superior these days. We tend to still use the same run proceedure as Henry Ford.

 

A mate of mine ran his 05 wrx in that way pretty much, now over 40k miles and still doesn't drink any oil between services.

I'm guessing that shows that in his case it worked fine!

 

Millers CRO10W40 mineral oil for up to 1000 miles increasing load with miles but no full throttle and not over 4K on mineral oil.

Change oil & filter at 1k for CFS10W60 and increase load and revs for next 250/500 miles

 

Do what the person who performed the re-build advises: they are the one you'll have to take the car back to if you break it and may not be prepared to honour any warranty if you've not adhered to their recommendations!!

Ns04

 

Useful information.
I will be going to germany to pick up ,my new WRX in a couple of weeks and need to drive it back 950 km to bring it home. Would it be harmful to drive it on motorways and vary my speed/load from time to time or is it a big NO?
Alternatively, I will have to take the country roads and maybe spend the night somewhere to give the car a break too
Do you avoid boosting at all for the first 1000 miles? It doesn't have a boost meter so how can you tell 0.5 boost ?

Thanks,

 

Great thread

I have just had my Sti 5 Wagon's bottom end rebuilt and picking her up tommorrow.

New spec is STi9 Nitrided crank and rods, Mahle pistons, acl bearings, carl daveys manifold and header spacers.