Originally Posted by Thermodyne
Harley's recommended oil is HD360, not Syn3. So it should be fine on dyno.
Now with that said, good luck finding 20-50 dyno that meets the 360 spec.
One reason one might have a hard time finding the HD 360 specs is due to their marketing team. HD through the early years didn't put much in writing and left it to their dealers to spread verbally what they wanted the public to hear like synthetics would ruin your bearings and any other gossip to ward off the competition whether it was fact or not. Once they brought out their own synthetic they had to make press releases that there was never a documented case of a synthetic hurting their engines. Since that time all their CVO's come factory fill with their Syn 3 synthetic oil.