"thinner" oil = change more often??

Took delivery of a Super Sport race bike that has 0w-20 oil. I understand that the thinner oils reach opitmal temps faster and are better suited for the closer tolerances of built race motors, but does it also need to be changed more frequently? Thanks in advance.

 

I'd be a bit leery of running 0-20 to say the least. You probably are good with 5-30, but if it's 0-20 you need to check cst at 40 and 100 centigrade and see if you are getting enough viscosity. As far as changing it, if it is dino oil yes, every race, if synth you can wait a bit longer. As far as closer tolerances of race bikes, I don't know whose idea that is. Cam tolerances are factory, and many builders WANT more clearance on rod and crank bearings, not tight. As that is where the most lube is needed, thinner oil works because the pump puts out more at high rpms.

 

Thanks for the timely reply. I was referring to a thinner head gasket etc. of a super stock build- not properly written. The engine builder delivered the bike with the referenced oil. Sounds like I can go two weekends before changing it. Perhaps then I will go with 10-40 cause the thinner stuff is so expensive and hard to find. Hopefully, the thicker stuff wont cause any problems.

 

Every oil is different. 10-40 can vary by 30% from brand to brand in viscosity at 100 degrees Centigrade. Thinner head gasket has nothing to do with the oil. If it were mine I'd probably run a 5-40 synth. But if it is a fresh motor get some mileage on it before going to synth

 

What did the builder recommend? Did you ask him your questions?

 

This afternoon. He said to use synthetic 0-10 or 0-30. Change every thousand miles.

 

Or he could not waste his time and just run a high quality synthetic oil from a well known manufacturer.

One of the reasons people run thinner oils is so they do not have to run clearances loose.

The thinner oil is going to have a higher flow rate than a thicker oil so you do not have to run your clearances at the wide end of the spec (or wider). Stuff will last longer with a tighter clearance.

 

I'd follow that advice then.

 

Actually well know synths vary in viscosity according to label. The 10-40 stuff is kinda thick, the 0-30 I would run in a motor. Maybe. But Redline, Royal Purple, Mobil one all vary considerably in viscosity in the same weights.

 

Most of the WSS guys run stuff like 0W-30 and 0W-20 and change it every day. They say it makes more power. I did a back-to-back dyno test on some of the unobtanium stuff one of the teams gave me and there was absolutely no horsepower gain over 10W-40 in a Superstock R6. Why go to all the trouble?

 

Dammit Rick,

Get outta here with yer facts n stuff, this is an oil thread, we don't need no stinkin facts!

 

SAE ratings for motor oil are SAE ratings. It is not fork oil. That is where cSt ratings are important as there is no standardized rating for fork oil like there is for motor oil.

You recommend checking the cSt ratings of the engine oil. What is the spec you look for and what methodology did you use to determine that was the ideal rating for your application?

 

I'd be checking the oil pressure at operating conditions to make sure it is where is should be.

 

Cst ratings are actual viscosity, the label is not. I look at 40 and 100 degree centigrade ratings. Manufacturers list the viscosity of their oil IN centistokes AT 40 and 100 celsius. A 10-11 at 100 celsius is probably ideal. Most of the 10-40s are 13-18. Oddly enough mobil one 10-30 has a great listing.

http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil_1_Extended_Performance.aspx

 

Luckily for you so does everyone else.

Again, would you please inform us as to what methodology you used to determine this was the ideal rating for your application?

 

I'll go back to this one. The SAE ratings are meaningless. The centistoke rating ( which you say is only for fork oil, LOL) tells you the actual viscosity, not some meaningless 10-40, 0-30, or whatever. It tells you at two points, 40 and 100. That way you actually KNOW what the viscosity instead of depending on the 0-30 label which you think means something. Run whatever CST level you are happy with. Sorry to school you but that's the way it goes. You want to know my "source". Well, sheeit, just run whatever YOU think is right. The only point I am making here is that the 0-30, 10-40 labels don't mean much of anything, as EVERY manufacturer has different standards.

 

I want hear about all the durability testing you did to determine what cSt rating provided the most protection/hp/longevity. I am sure you have reams of data chocked full or cam lobe measurements, hardness tests, etc.

Otherwise someone might think you went to a site put by someone full of shit that has multiple charts/graphs for every one of his posts and think he walked away with the secret of the universe.

 

Obviously you have not done the research. Do some. 10-40 dino oils vary hugely in viscosity at both 40 and 100 degrees centigrade. Ditto synthetics. "A good grade oil" is meaningless unless you KNOW what the viscosity of the oil is. There is plenty of data out there, read it.

 

Why would you not listen to your engine builder?

 

A. It's fun.

B. You're stoopid.

C. You're AMAFan