Zinc & phosphorus in oil
 

Should Kohler engines be run with oil containing zinc & phosphorus? If so, which brand 30W oil can be used, or should a zinc/phosphorus additive (like ZDDP) be used?

Valvoline VR1 racing oil has zinc (zddp) and phosphorous additives. It says "Not Street Legal" or words to that effect on the container. The additives are hard on catalytic converters. I used it in my air-cooled racing engines. There may be other brands on the shelf also.

Thanks, Gary. Do you use the Valvoline VR1 in your Kohler engines?

I haven't used it in Kohlers but only because I don't have it on the shelf anymore. I wouldn't be afraid to use it at all. NAPA carries it or can get it. The air-cooled Porsche guys used it when I raced and even my engine builder recommended it.

It looks like the VR1 is street legal, not that it matters, and available in 30W. I used the 'Not Street Legal" 20W50 in the car.

http://www.valvoline.com/pdf/vr1_racing.pdf

I have been using that in all my old air cooled small engines for many years, no
issues at all...My .02 Dan

Mobile Delvac diesel engine oil. other diesel oils are good to. I tested the Delvac. several years ago Harley Davidson did an oil study comparing various types of engines, gas, air cooled vs diesel vs gasoline car engines and said diesel engine oils meet the requirements needed for air cooled gas engines better than any of the other oils out there and recomened using Diesel engine oils in case the genuine HD brand oil was not available. I've run Delvac in some very expensive Kohler pulling motors for 3 or 4 years now. We see no excessive wear vs what we used to run amsoil 20-50 race oil which was very good. We did go to less runs on oil changes. 4 - 5 vs 8-10 for the amsoil. I have used it in an old K series I have in one tractor I use allot for at least 3 years. in the end oil's oil and if you change it regularly and keep the level full they all do good jobs.

Bingo, we have a winner! I run Delvac or Rotella T in my stuff including my HD Night Rod. Also used to use it in my race car. I used to run my Cats & Cummins on Delvac and never opened one up for an over haul with less than 20,000 hours on them.

and its pretty cheap

I run this in my air cooled engines. I can't find 30WT Kohler oil anywhere. Rotella is good too.