2 Stroke Oil

Jack ODonnell · Apr 13, 2018

Hi John; We never had any bearing or seal problems. Mr. Jim Wilson ran our fuel with 8% oil for a number of years with out any engine or fuel problems. J. Jeff; I don't know anything about the (premium 500 oil ) our oil package came from a retired 3-m chemist .My son Steve does not want to let any info out about his oil package. J.

Ken Retallick · Apr 13, 2018

Those that have run or seen tether cars run, they use 20% castor oil only. At the end of there run they shut the fuel flow off completely, this at 30.000 rpm or much more for the smaller engines. The car slowly comes to a stop after many laps. This is with No fuel/oil flow at all.

Has to say something about the residual oil left in the engine. Would be interesting to see if the engines survive using synthetic oils.

Rudy Formanek · Apr 14, 2018

Ken, almost all the 6.5 cc 2 cycle pylon racers since the inception of Formula 1 in RC airplanes have run venturis and fuel shut-offs. They were a high nitro, mini pipe engine, just a straight 3/4 dia 4 in long mini pipe. If fuel shutoffs were harming the P/L fit or wearing the bearings, I would of thought at least a few people would have been running flood offs, but absolutely no one was. Like nitro boat motors they had a short hard life, not like engines would last 3 or 4 seasons, most were rebuilt after 1 or 2. From what I saw most ran a majority of lube as synthetic, probably quite a few ran castor as a percentage, though. Airplane guys never had the problem with rods/ bearings that boaters do. If they have gone to bigger rear bearings its been because they wanted to make the hole through the crank bigger, like in the Nova Rossi 21's, not because the rear bearing was failing as in the marine OPS 45.

PaulHail · Apr 14, 2018

IMHO our drivelines and props load the engines more severely than aero props, hence the issues we have with bearing and rod failures.

El Zorro · Apr 14, 2018

Bingo! A couple of guys here that understand what's going on. I always ran a percentage of castor oil in my airplane fuel. I spoke with Dale Kirn ( long time speed engine guru who worked at Cox Mfg. for a time ) at the 1980 Dayton, Ohio AMA Nats and he used castor for years and told me that in the ,049 engines you needed to run 20% total oil with half of that being castor. Plain bearing engines need MUCH more castor than ball bearing engines ( controline stunt, sport flying, R/C. etc. ). In any racing engine ( airplane, boat, car, etc. ) it is the best thing you can do to add any kind of longitivity ( ? ) to an engine. Some people can set a needle on a nitro engine better than others. You can usually pick these people out by how full their "broken parts bucket" is. I have had people tell me that using castor oil only slowed them down and they didn't need it. I guess that's like when some people disagreed with me about quiet pipes made their boats run slower more than 20 years ago. What happened with that? Do yourself a favor and use some castor in your fuel. There are a lot of people out there that make really good fuel ( John Otto and Allen Elzer come to mind ) that make really good, clean fuel and at a reasonable price. You will be doing yourself a favor.

Dick Tyndall