Mark, Thanks for the input. The plane already has a high volume pump on it. Pete said that since he put the 5th bearing on it the pressure has been lower.
Can I run 20w-50 oil in it? That would be the simplest solution. Its got Rotella 15w-40 in it now, but why not use a high zinc 20w-50 such as a Brad Penn oil (which is what I run in my VW)? There are a few holes in the baffles I am going to patch up. Opening the outlet to the cooler has not made much of a difference since we originally gave it two 1.5" exit holes. We added two more exit holes that are 1.75" each will little change. Closing up the leaks should help the temps and the pressure. Jeff Lange Race 64 - Skye Racer Blog: http://schmleff.blogspot.com Youtube Channel: https://www.youtube.com/schmleff On Jun 23, 2013, at 10:06 AM, Mark Langford <ml at n56ml.com> wrote: > Jeff Lange wrote: > >> What is the max acceptable oil pressure for a Corvair engine? >> What is considered the max continuous oil temp (we are using the >> recommend Rotella oil)? > > As you already know, adjusting that oil pressure relief spring only changes > the upper limit of where the oil system dumps excess oil pressure back to the > sump, so max pressure is raised, but the lower pressures reached once the oil > is warmed up are still low. The usual answer of course is loose bearing > clearances and that kind of thing. As you also know, the general rule is 10 > psi per thousand RPM, so you are right at that limit. Having said that, I've > flown with less, but only long enough to put a higher volume oil pump in it. > Clark's makes at least two different versions in them and I've flown both > with good results. They'll bring up pressures throughout the range, although > more pressure will be dumped during cold operation. > > The "power robbing" point is the main downside of a high volume pump, but > another downside with the Corvair is that the oil pump is run by the > distributor drive gear on the bottom of the distributor. That gear has a > slot in the bottom that turns the pump, and the gear is pinned onto the > distributor drive shaft by a pin. That pin, subjected to enough shear, can > shear in two, leaving neither pump nor distributor turning. I've heard of > this happening, but don't know anybody personally that it's happened to. It's > relatively rare, and may involve extenuating circumstances. If I'm not > mistaken, William Wynne replaces this pin with something stouter, so this is > an option, and maybe has already been done to yours. It's insurance against > a problem that is made more likely by use of a high volume pump. Having said > that, all of my engines have used a high volume pump except for a 2700cc > experiment that I ran for a short while. Since I have a remote cooler and > filter, I feel the need for a high volume pump, and will never go back. It > does make a difference. > > To answer your question, most folks I know consider 55 psi to be just about > perfect, and certainly not too high. On a super cold day with no preheat, > it'll climb above that as the bypass valve is overpowered. If it gets over > about 85 psi, I'll make sure my oil filter isn't puking oil before I take > off, by doing a few donuts before takeoff. It happens! > > 220F wouldn't bother me, but the 29 psi at 2950 RPM is getting there. A high > volume pump will certainly improve that. > > By the way, I never saw your CorvAircraft post either, so you may want to > repost it there. You may have the old address. The new one is given at the > top of http://www.corvaircraft.org/ . > > Mark Langford > ML at N56ML.com > website at http://www.N56ML.com > -------------------------------------------------------- > > _______________________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options
