Which oil weight
 

What would recommend for oil weight with 003 mains clearances? Street strip being used in weather ranging from 40 to 80 degs f

Using Valvoline VR1 racing oil with those clearances. 10W-30. Water temps 170-180. Hot oil pressure: 18-22 PSI @ 1000 RPM 60 PSI@ 3000 RPM.

Thank you

What is the rod bearing clearance? What type of lifters do you have, hyd, solid, flat tappet or roller?

Tim, not sure on the rod clearances. Lifter are solid flat tappet.

There are many different brands that will work for you. Everyone has their favorite oil but for a flat tappet cam you will need an oil that has a good ZDDP package. The one I prefer is Brad Penn you could use their 10-30 or 10-40 and you can get it on Amazon.

I've used the Brad Penn in the past with good results. I'll see what my engine builder recommends as to weight, then decide.

Driven GP-1 oil deserves looking into.

0w-40 mobil 1 euro has a good bit of zddp.

I'm using 10-30. I switched from 10-40 while the motor was on a dyno, recommended by the operator due to excessive oil pressure. Dropped the pressure by like 30 psi at 6000-6500 rpms

Just a note on Brad-penn my machinist said they sold the company
and took a lot of the ingredents out I think he said the ZZDP also
Might want to check that info out, I been useing a differant brand
sence then. can't remember what he is selling now I'll check and
get back to let everyone know...

GT

I have been using 20/50 in everything I build it’s what has worked for me for 35 yrs.

Brad Penn oil is now Penn Grade wirh
all the additives

https://penngrade1.com/

Even with 003 mains clearances?

driven oil viscosity chart
https://www.google.com/search?q=driv...0UiFKM&vssid=l

What ingredients would be taken out of an oil because the brand was sold? ZDDP definitely wasnt removed from any oil...

All oils have ZDDP in them & most are at pretty good levels around 900-1000+ppm, along with other modern anti wear additives it is enough to support most stock to mild street cams. If the cam is a "race" type cam since this is the race section, them you may need a higher amount from a race type oil like VR1.

With street type clearances there is no benefit to using 20/50, use the weight that gives good psi & is acceptable for the temps youre driving in... 40-50 degrees is way to cold for 20/50, especially with .003 clearances... unless for some reason the engine oil temps are excessively hot.

The only thing that really stands out to me on the viscosity question for the original post is how aggressive on mechanical cam is in the engine? If it is aggressive, I pretty much automatically start with 20w50, and keep with it unless a future oil analysis or something about the engines oil pressure tells me differently. Some engines are hard on oils, maybe the oil gets hot, maybe the engine runs rich and the oil gets diluted. With a flat tappet cam, I would rather start with thicker oil on those cases, and lower the viscosity later if needed.

I have pretty much different weight’s and oils in almost all my engines. We (try) picking the oil and it’s weight to address the particular area of the engine we are concerned about the most. With an aggressive mechanical cam, that is usually good reason to go heavier. Hyd rollers generally we keep on the lighter side, 10w30 or 5w40. The thicker oil film on the flat tappet cam and lifters doesn’t seem to hurt, so we stick with 10w40 or thicker. For cylinder and ring wear, most the studies I have seen showed lighter weight oils had less wear. A lot of times you won’t really know what the engine wants until after you run your engine.

motortrend posted a video of testing viscosity
i'm wondering if a vacuum pump were used if the results would have really changed, same with engine stroke, and.... guess the list could go on and on
bascially saw no real difference
conclusion was ring seal with the thicker oil
i run 20w-60 motul, well now it's 10w-60 but thats because i am in the dessert with very high temps
even the 20-60 when you shake it sounds like fine water

i do remember when there were straight weight oils at the store, one would use them (thicker like 60 or 70) if you had a leaker, burner, or knocker with thinner oils, especially when people would sell their cars.
guess thats kindda evil thing to do, but i've heard it works (of course depending how bad it was)

These are 2 shots of. The Dyno sheet from the same day, only difference was using Royal Purple 10-40 which produced more oil pressure than the Dyno operator was comfortable with, switched to Penn 10-30. .sorry for the fuzzy quality of the one screen shot.
This is with .003 main clearance

Did u have a Titan oil pump? Thats a lot of pressure.