Oil viscosity?

19 69 GTX

Well-Known Member
Local time
7:32 PM
Joined
Apr 30, 2016
Messages
352
Reaction score
212
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
 

Beekeeper

It’s a disease without a cure!
FBBO Gold Member
Local time
6:32 PM
Joined
Jul 4, 2012
Messages
4,172
Reaction score
4,140
Location
Rogersville,TN.
your bearing clearances should be used to determine what grade oil you would use.
Maybe talk to your builder to see what they
recommend.
 

Lefty71

FBBO Gold Member
FBBO Gold Member
Local time
7:32 PM
Joined
Mar 8, 2018
Messages
2,443
Reaction score
2,646
Location
Ohio
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
 

Lefty71

FBBO Gold Member
FBBO Gold Member
Local time
7:32 PM
Joined
Mar 8, 2018
Messages
2,443
Reaction score
2,646
Location
Ohio
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:
 

19 69 GTX

Well-Known Member
Local time
7:32 PM
Joined
Apr 30, 2016
Messages
352
Reaction score
212
Just talked with him he said go with a 15w40. Anyone ever use a 15w40 rotella t4. Believe it's a semi synthetic
 

66Satellite47

FBBO Gold Member
FBBO Gold Member
Local time
5:32 PM
Joined
Jan 15, 2015
Messages
6,433
Reaction score
5,491
Location
St Paul MN
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.
 

Geoff 2

Well-Known Member
Local time
6:32 PM
Joined
Jul 21, 2014
Messages
361
Reaction score
156
Location
Australia
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.
 

Challenger340

Well-Known Member
Local time
5:32 PM
Joined
Mar 4, 2014
Messages
816
Reaction score
886
Location
jaffray, B.C. Canada
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 ?
 
Last edited:

SlinktRR

Well-Known Member
Local time
7:32 PM
Joined
Aug 27, 2012
Messages
1,232
Reaction score
639
Location
Houston TX
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.
 
Top