Oil + additive viscosity
The reason for a thicker viscosity is that the valve train is slightly quieter with say 20w60 as apposed to 15w40 oil. I am running an extreme energy cam with sharp rise and fall lobes and the valve train does sound a little like a solid cam profile. But I must admit the engine does feel more lively with the thinner 15w40 oil. It revs and responds better. My question is that just because the rocker gear sounds a little noisier does this mean there is potentially more stress and wear on the valve train?
Regards
Billy D...
Go to yellowbullet.com and get into the forums.
Click on the Uratcho race engine forum.
Click on the crankshaft thread. There are several well known Pro Stock engine builders posting in that thread about oil viscosity, bearing clearance etc.
Never use any additive in the oil. If you are using a quality oil, it was designed with everything it needs. You adding something to that oil changes the entire chemistry of the oil.
If you need to use an additive in your oil, buy a better oil.
There is zero reason to run a 20w60 oil unless you are in Africa heat. Even then it's questionable.
How are you sure the valve train makes more noise on a heavier grade oil? By ear? Not very exact.
Also, heavier oil means less flow. Less flow means less cooling by the oil. Like coolant in the engine cooling system you need oil flow.
Unless you bearing clearances are .0035 or more that oil is too damn heavy. If your clearances are that big, then I'd have to ask why.
Edit: the title of the yellowbullet thread is crankshaft size.
