Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties Racing oil

Racing oil

Post Wed May 24, 2017 5:47 am

Posts: 1735
The flathead is running now. I've started it and run it through using a 20/50 oil sold by Halfords for "classic cars" which I find from experience, works well in older street bikes

But, what about actual racing? What grade or type of oil do other members use?
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Wed May 24, 2017 2:31 pm

Posts: 3350
Location: Central Illinois, USA
Well, 45 Brit,

My days of supporting racers are far behind me, but,...
How bad do you want to win?

Competition is different than daily duty; Light oil allows quicker accelleration and less internal resistance. Drag racers were known to dump it all before a race.
But they fully expected to rebuild between events.

Otherwise, the universal rule is simple: "Clean oil, and lots of it".


Post Wed May 24, 2017 7:59 pm
Pa Site Admin

Posts: 6085
Location: Ohio USA

I agree with Cotten. The thinner the oil the better for racing. Bearing fits and the like should be loose as well. A race bike needs less friction, less drag, and be as loose as one can get it throughout the engine and gearbox, minus the pistons and rings, without sacrificing performance or blowing it up before the race ends.

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