Oil Brand & Weight Revistited

[norcalsvt]

I have always used the oil that the builder of my 347 stroker recommended. Royal Purple Racing oil #9. Never paid attention as to what weight until recently & discovered it's a 0w10. I was thinking of changing to a 5w30, but a guy who builds high performance engines said to get 0w30. Now Im confused. What do you guys use? I read mobil 1 0w30 is no good, but amsoil's is. What about mobil 1 5w30? or Maybe a good dino oil?

 

[NorCal66]

Well, I'd think the builder would know best. Engines with really tight tolerances, such as new cars, real thin oil. Any reason for wanting to change?

 

[67GTA-FB429]

I know that race cars (see: NASCAR) use the lightest possible lubricant they can without having the engine blowup. The extra viscosity will rob power.

 

[LMan]

This is hard to answer without knowing your bearing clearances....that is kinda thin oil for a street motor, though. Do you know your clearances? What do you use the car for?

 

[norcalsvt]

as far as bearing clearances I really don't know. I purchased the car about 8 or so months after it was built & the seller was told this so he relayed the info to me. I'm just thinking it seems like a very thin oil for the street. I use the stang as a daily driver & I doubt I would ever take it to the track.
I'm just trying to figure out why a oil so thin. I know the engine definetly gets very hot & takes hours to cool down,so Im not sure if this is a reason. I was thinking the oil was only recomended for the break in, but what do i know?
I guess you guys are recommending I stick with it

 

[Red66GT]

Here's a great link I found about oil. http://www.boss302.com/oil.htm

Out of curiosity, does anyone run Synthetic in their old blocks?

 

[NorCal66]

M1 Full synthetic 15w-50 in mine. No leaks, but that stuff is like honey.