Mike in Mn.
Member
Assembling a gasoline puller engine, short block has about 50 hour on it, had been running Rotella T with a Lucas zinc additive. Every thing looks ok but a lot of breather stink and enough carbon on pistons, run it in another puller and one of our farm tractors and the same thing, breather stink and enough smoke off idle etc. I have run Case/IH bulk, Valvoline, Chevron etc over the years, all good oil. Right now I'm running Amsoil 15/40 in the diesels and 5/30 in the car and pickup and stretching the drain some, but within reason and am having real good luck with this plan. Any way I'm thinking of running Valvoline full synthetic racing oil (20W50) in this engine, I know this subject has been beat to death here, but what do you think?? Racing oils have zinc already in them and are suppose to let an engine develop a little more power according to there statements and specs, baloney or truth?? Thanks for your thoughts.