Hello folks, a new guy here.
I've an early '84 Harley FLH Shovelhead. I'm currently using Amsoil's straight 60w synthetic oil(AHR)in the motor.
I live in Northern Mn. where temps are on the cooler side, but rarely ride it when it's below 50F.
I'm using this weight oil due to the fact Amsoil has it as their first pick(over their motorcycle 20W50) for use on Harley's pre Evolution motors.
I've been asked, and don't know the answer, why I wouldn't run 20W50 instead. I have read that synthetic straight weight oil's do act somewhat like a multi viscoity dino oil, ei they thicken less when cooled, but not sure to what extent. Shovelhead's have roller bearing's in their lower end's and generally tolerances are much looser than on most modern engines, but still?
Will a synthetic 60 weight provide adaquate protection on cold start-ups @ 50F in this type of motor?
Does it's ability to hold up better to the higher shearing effect these motor's have on an oil outweigh the cold startup protection a multi viscosity synthetic 20W50 would provide?
I figured I'd ask the experts, and thanks for any input!
I've an early '84 Harley FLH Shovelhead. I'm currently using Amsoil's straight 60w synthetic oil(AHR)in the motor.
I live in Northern Mn. where temps are on the cooler side, but rarely ride it when it's below 50F.
I'm using this weight oil due to the fact Amsoil has it as their first pick(over their motorcycle 20W50) for use on Harley's pre Evolution motors.
I've been asked, and don't know the answer, why I wouldn't run 20W50 instead. I have read that synthetic straight weight oil's do act somewhat like a multi viscoity dino oil, ei they thicken less when cooled, but not sure to what extent. Shovelhead's have roller bearing's in their lower end's and generally tolerances are much looser than on most modern engines, but still?
Will a synthetic 60 weight provide adaquate protection on cold start-ups @ 50F in this type of motor?
Does it's ability to hold up better to the higher shearing effect these motor's have on an oil outweigh the cold startup protection a multi viscosity synthetic 20W50 would provide?
I figured I'd ask the experts, and thanks for any input!
Last edited: