Running-in oil?

[dede]

Hi,

I tried different types of oil in by new rebuild porsche 3.2 (air cooled) to improve oil consumption.
Car has been rebuild 8000 km ago and from the start got synthetic 5w50.
After the fist oil change I filled her up with 5W50 ester oil (local brand).
Oil consumption on motorways is between .5 and .75 l/1000km. On track it is difficult to measure.
I also tried semi synthetic 10w40, also around .5l
Last week I used ester based 10w60, comparable figures.

According to the tuner/builder of the engine, all is normal and will even improve after full bedding-in.

I think that the rings are indeed not fully bedded in.

Does it make sense to g to mineral (or even running-in oil), to get better/faster bedding in of the rings?

Thanks,

André

 

[Lead Shoes]

It took quite a bit of rev hanging and purposely vacuum coasting from high rpms down to nothing to seat the rings in my b17, right around 200 miles on Amsoil break in oil.

By 8000km I would hope the rings are seated in enough to curb consumption, that is quite a high rate of consumption.

 

[nitehawk55]

The rebuilder who did your engine , is he reputable and well known ?

He should look after you if the consumption does not stop .

 

[dede]

Yes,

he is very well known.

 

[Lead Shoes]

Just curious what oil did you use during the break in period? hopefully high in zinc, phosphorus, and calcium with almost no moly or boron... basically no friction modifiers.

 

[Brit33]

Hang on!
Are you using synthetic oil for break in??
If so the rings will never bed in properly and will remain an oil burner for ever.

You need a very good hone of the bores then a hard break in with mineral oil only.
Castrol gtx 20w50 is fine for break in.

 

[dede]

He filled it up with synthetics during break in.

This is nor exceptional in the porsche world apparently, but I do have some concerns.

I have plenty experience on rebuilding BMC A and B series engines, and I always used running-in oil.

Does it makes sens to fill it up now with running in oil, or if converting to mineral, this will help seating the rings?

On the other hand, the porsche owners manual say that oil consumption is allowed up to 1.6l/1000km.

André

 

[gregoron]

What oil did your engine builder recommend? If you can, I would suggest Mobil 1 0w40 since you've already put 8k km on the engine after rebuild. Going back to dino is moot now. M1 has a high VI and flashpoint. It helped reduce consumption on my 2k Jetta, which is known for that problem.

 

[901Memphis]

Maybe you're not running it hard enough ?

 

[dede]

The engine builder recommeds 5W50 synthetic.

Running it hard: I have in the meantime done around 5 trackdays, redlining if possible.

Power output is very good. On an independant rolling road it made 249 hp and 325 Nm torque

André

 

[Brit33]

Running in now with mineral now is useless.

I'm inclined to think the bores are glazed and will never bed in.
This is common if not bed in properly with the right oil.
Any competent engine rebuilder should know this.

If they are glazed and burning oil the only solution is to strip, hone, fit new rings and bed in again with the right oil.


Did they use a flexhone to produce a nice hatch for the bedding in?
What grade and material? What rings were fitted?