What brand and grade oil for a Legends car

[Fatboymoe]

My Brother-in-law has a Legends race car. It's powered by a Yamaha FJ motorcycle engine. This engine is air cooled and has 2 large oil coolers with a remote oil filter. The engine is also sealed to prevent tampering to any internal componets.

He told me that most of his fellow racers use Castrol GTX, because of Castrol's ability to handle the heat. Oil temp's above 300 deg F are not uncommon during races. This engine-transmission set up uses a shared oil system, with a wet clutch.

I think that there are much better oils than Castrol GTX for this type of car. Any thoughts?

 

[sunruh]

what kind of oci's is he doing with it?
i've tested castrol gtx 20w50 and castrol motorcycle spec 20w50 and the gtx sheared out of grade very quickly and the ms was not a lot better.
at this point in time, i would suggest either Valvoline VR1 Racing sae50, Exxon Superflow 20w50 or Shell Rotella T 15w40. this is based on the 18 uoa's i have done on my bike (which is essentially 1/4th size and water cooled).

 

[jonny-b]

Hello. If he races the car hard, then I would have used Royal Purple Racing 21. He could also use RP 5/30, because it is cheaper. Anyway, to use 15-20 USD extra on an oil that will last 2-3 times longer than what he is using now, is a no-brainer. Here in Norway, I have seen several racing-teams switching from Castrol to RP with great success. Without exception, they report about temperatures going down and oil lasting longer. Also, many of the teams have to rebuild their engines after one season with the use of Castrol, but are experiencing that they don't need to rebuild their engines, when switching to RP. If I were you, I would take a look at their home-page( www.royalpurple.com ), just to see what can be the reason to why their oil seems to give better results. Good luck.

 

[jonny-b]

Of course RP have motorcycle oil as well. I saw 4-5 Harley's being tested, using warious types of oil when testing started and then, under the same condition, shift to RP. They were meassuring both temperature-reduction and increase in horsepower. Temperature reductions were from 10 to 40 degrees Fahrenheit, and increase in horsepower up to 2,5 percent.

 

[Jim 5]

My fj1200 called for 10w30 in cooler temps and 20w-40 in hotter temps. (20w-40 yamalube).

Plenty of people on the fj1200 sites use Rotella 15w-40 hdeo as well as M1 red cap 15w-50. For a racing application, I wouldn't consider a 10w-30 for a shared-sump situation. The gears will shear the oil dramatically and quickly.

do a search for some fj1200 sites...and check there as well. Also, check out the motorcycle UOA and motorcycle sections here. "Blake Sobiloff" has contributed some excellent posts and UOA's on the subject of motorcycle oils/ motorcycle applications vs. car oils. You might want to search those sections by his name.