Run-in oil

[wings&wheels]

What are folks using for run-in oil these days?

Aside from new cars, which are a different situation, I haven't run in a new auto engine myself in ~30 years. I see many of the boutique manufacturers are offering them, and I expect my engine builder will recommend one but I like to get a wide pool of opinions. Engine is a 2.0L SOHC I4 M10 engine from a '74 BMW 2002. Eventually she will get my go-to oil for my Summer only vintage cars; M1 15w-50.

Thanks.

 

[SeaJay]

I'm not a true bitoger, I use the oil the car came with for the first 6 or 7 thousand miles.

 

[wings&wheels]

Originally Posted by SeaJay
I'm not a true bitoger, I use the oil the car came with for the first 6 or 7 thousand miles.


I do to with new cars usually, but this is an engine I am having rebuilt.

 

[MCompact]

In the mid-nineties before BMW switched to synthetic oils it was recommended not to run synthetic for a bit over 5k miles. I suspect that may be the case for your M10. My OM for my 318ti recommended okayed 15W-50 down to 0F, although I now run BMW TPT 5W-30 as it is no longer a track toy.

 

[ragtoplvr]

You are before the roller cam era so I would use a 10W40 conventional motorcycle oil for break in or valvoline racing oil in 10w40 after break in, then a 20W50 mtorcycle oil will work well.
They know motorcycle will sit around a lot, and most Harleys still use cast iron bores so they have good corrosion and rust prevention.

Rod

 

[wings&wheels]

Originally Posted by ragtoplvr
You are before the roller cam era so I would use a 10W40 conventional motorcycle oil for break in or valvoline racing oil in 10w40 after break in, then a 20W50 mtorcycle oil will work well.
They know motorcycle will sit around a lot, and most Harleys still use cast iron bores so they have good corrosion and rust prevention.

Rod


Thanks. I do run one of my very limited use cars on M1 20w-50 for those reasons, and it is a recommended weight. I may look towards a non-synth MC oil for this.

MCompact, thanks. I used to run Castrol 5w-50 (before the Castrol vs. Mobil what is 'synth' issue) in my 318ti...miss that car.

 

[Oildudeny]

0w20 usually NAPA full synthetic with OE filter 6 month oci's

 

[Trav]

Gibbs BR50 15w50 break in oil.

https://www.drivenracingoil.com/br-15w-50-conventional-break-in-oil.html

 

[wings&wheels]

Originally Posted by Trav
Gibbs BR50 15w50 break in oil.

https://www.drivenracingoil.com/br-15w-50-conventional-break-in-oil.html


Thanks!

"..up to 400 miles on the street", interesting.

 

[Trav]

Probably not the best thing for a cat for much longer than that especially with a rebuilt engine that tend to use a little oil initially.

 

[wings&wheels]

Originally Posted by Trav
Probably not the best thing for a cat for much longer than that especially with a rebuilt engine that tend to use a little oil initially.

That is what I figured. No cat here so no problem. Thank you again.