(quoted from post at 20:19:12 01/19/14) I am in the process of treating down a flat tappet engine. The Cam was reground, and lifters resurfaced about 5 years ago. This is just a puller, and had very few hours on the motor.
the Cam and lifters are done. The lifters have not been rotating in the bores and are badly worn where they contact the Cam. When they were assembled, they got lots of Cam break in Lube.
What do i need to do so that this doesn't happen to the new can and lifters?
Break-in
Synthetic oil break-in for high performance engines is common and there is no reason why it cannot be used for lower RPM tractor engines. Royal Purple Break-in oil and Joe Gibbs BR both work acceptably well in and have been using one or the other for many years for flat tappet racing engines. I just happen to use Gibbs oil at this time due to a cost break from my supplier.
For engines using a billet cam, billet hard coated lifters with EDM oiling, and up to 500lb OTN spring pressure, we are not using break-in springs or low ratio rockers for break-in. Run engine as-assembled, for 20 min to operating temp, set timing, shut down, set lash, drain oil, check filter for debris, if OK, pour in XP3 and the engine is ready to go.
For engines using a cast iron core cam and iron lifters, remove inner valve spring or use break-in springs with seat pressure less than 100lb. Run for 30 min at operating temp 180-200 deg F, set timing during run time, shut down, set lash, drain break-in oil, check filter, if OK, install operating valve springs, pour in the XP3 and its ready to go.
During run-in we are establishing wear patterns that can be maintained during service. I’ve not had a cam or valve train failure in 15 years.
Operating with Synthetic Oil
The long term life of a tractor engine may not like synthetic oil as an automotive style engine. Unlike racing engines, many tractor engines lack the same valve train/upper end oiling, without modification. Compared to a racing engine, tractor engines starve the valve train, but the volume of oil was adequate under conditions for which the engine was designed. In a true high performance engine, the valve train is literally flooded for both lubrication and cooling. For a tractor engine, it may be better in the long run to use a petroleum based oil such as Kendall 20W-50W, an oil that clings, drips, and does not drain off as fast. An established tractor engine builder would have to answer the long term benefits of running synthetic oil. Synthetic oils in racing engines are used to reduce both friction and crank case windage and I would guess these features are not nearly so important where an engine rarely sees 3500 rpm compared to an engine that never drops below 3,500.
