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Oil viscosity?

19 69 GTX

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Fresh 512 all roller engine build. Just curious after break innwhat viscosity I should run in it. It's a street car 90%. Should I go with say a 20w50 synthetic race oil or conventional
 
your bearing clearances should be used to determine what grade oil you would use.
Maybe talk to your builder to see what they
recommend.
 
These questions are always best left to the engine builder first.... We don't know what the bearing clearances are, nor the oil pump/pan/pickup setup. Personally, for a street car, I would stick with a synthetic after break-in, but I would'nt use 20w50 on the street especially in cool weather unless the machinist said I have too. A lot of people don't realize, any potential oil consumption is increased by use of heavier weight oils. HTH, Lefty71
 
your bearing clearances should be used to determine what grade oil you would use.
Maybe talk to your builder to see what they
recommend.

Lol, i was typing and thinking too long. :thumbsup:
 
Just talked with him he said go with a 15w40. Anyone ever use a 15w40 rotella t4. Believe it's a semi synthetic
 
The builder of my 512 is a top quality builder. He surprised the heck out of me when he said to use 20-50W Penn Grade. His recommendation became a little more clear when I read his build sheets and the bearing and rod clearances. Later I learned that the Penn Grade is the same as the old Kendall racing oil. That was the best oil I ran in my bracket motors back in the day.
 
I run the best of both worlds: 10w/60. Pours like a 10 on a cold morning, protects like a 60 on a hot day of freeway driving.
 
So you are just installing your 512 in the Car ? No Dyno'ing ?
What are the internal Bearing Clearances ?
Where is the spec/build sheet on the Engine ?
Did your 'builder' Machine the Engine as well or just 'assemble' the Engine ?

What if the rear Main Seal leaks ?
Water Leaks ?
EGT's ?
etc.

My apologies here but just say'in.... if it's an 'all roller' Engine and you don't even know the Bearing Clearances from a "Build Sheet".... let be the V/Spring Seat Pressure or Rate that was used ? Cam End Thrust ? Ring End Gaps ? Pin-Fit ? Valve Lash ? .... and on and on and on...
What Oil to use could be the least of your worries ?

No matter...
you still need Zinc in the Oil for patent break in on the rings.... because I'll be damned if you know the Hone/Plateau procedure used either ?
 
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roller affords you the ability to pretty much run any modern oil after break-in, synthetic or conventional. Try to stay above the 10psi per 1000rpm (hot) rule and adjust your viscosity accordingly. I would guess 20w-50 would not be ideal unless the bearing clearances are large.

I have a solid flat tappet and only use conventional 10w-30, doesnt dip below 15-20psi at 1000rpm at temperature.
 
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