Break in oil viscosity

Break in oil for flat tappet cam…..10-30 or 10-40?

using Driven BR product.

mains are 2.3, rods 2.0-2.1

running slightly lighter springs for break in…..closed 110, open 275 for the cam break in.


Any preference on break in oil weight?

 

Either or.

 

Whatever gives you the hot oil pressure you are looking for. On my engines, I've run the 5W30 and it has great hot oil pressure.

 

Thanks for input. I’ll be getting BR30

 

I wouldn't use 5W-30 for break in with a flat tappet cam. Need more film strength that 5 weight can provide IMO.

 

Im trying to have a successful flat tappet experience.....saying that ill do whatever is needed to have best chance for success. Ill double check the viscosity of the Driven products.

 

Why do they say "good for one night of racing"??

Note the 5W-30 does not mention flat tappet cams as the 10W-40 and 15W-50 do.....

 

I’d say the 5/30 is too thin.
I’d never run less than 10/30 in an older Buick or any older V8

 

The additive package is specialized for break-in. The long-term additives aren't in there, so the service life of the oil is SEVERELY shortened, just like most "Racing" oils.

 

But no day racing.....

 

No, just night time, the daytime UV rays break down the oil

 

It *DOES* say, "The same high zinc and phosphorus formula as our original break-in oil" which tells me it has the prescribed levels. I ran 5W30 in my 455 for break-in back in 2015 and it is still running fine with 5W30 regular high zinc oil. The trick is to know your clearances and what is needed to get good oil pressure.

 

Yes but does not mention flat tappet cams. Too thin for cam breakin. Need more film strength on the cam lobes if cam aggressive at all.

 

Using the 10-40 BR

 

I would offer that proper viscoscity is dictated by bearing clearance and operating temp, break in or not. See attached which jives with what I was always taught...

https://www.enginelabs.com/news/what-i-learned-today-bearing-clearances-vs-oil-viscosities/

 

I'm not talking about bearing clearances....I'm talking about cam breakin where there is ZERO clearance...only the oil film.

 

Sorry - mis read the original question. So in that case: lifter face surface, spring tension, moly lube and ZDDP are your friends and viscoscity ia lot farther down that list..

 

a lot of reading came up with straight 30 weight non detergent with lucas zinc break in additive or similar additive. it was also the fastest ring break in I ever had.

 

I used straight 30w on the last two I did.. did not add any additives through, just used straight break in oil. Also used that Quick Seal powder for ring break in - they were seated before the timing mark came back around to zero!