Maybe an old topic, but I have to ask anywayafter an extended ramp wait and taxi out, flew for about 15 min, saw oil pressure climb well above 100 psi (capillary tube gauge) and temp still maintaining 200. Made precautionary landing, and checked both the rear regulator piston, it slid right out on its own. checked the front oil pump regulator, and it was not quite as easy to get out, but did so with a bit of help. saw several scratched on the outside of piston, scotchbrighted them off, reinstalled and pressure after 20 min ground and taxi run, stayed at 65-70 psi where it had been. Problem solved, IMHO, but I wonder if anyone else has seen this high oil pressure? VR1 20w/50, 86hrTT,100LL. Maybe these regulators may have to be looked at durring condition inspections?
Not sure any of my comments will be of help to you. Anyway, when I was flying a VW Sonex nose-roller many years ago I had left the American Sonex Association gathering and was heading towards my fuel stop in Georgia and the OP locked on 80 PSI. Of course I didn’t want to believe it and reducing the throttle made the number come down but I needed power to stay aloft. (At that time I was using Valvoline VR-1).
Straight ahead was Dublin so I radioed them and landed. After shutting down, checking the oil level, and seeing what I could see, I climbed in and restarted the plane. Everything on run-up was normal so I took off with a promise to them and myself that if something wasn’t right I’d turn right back and land.
In the many hours after that, up until I sold the plane, it never occurred again. Go figure.
These days, of course, I’m flying with Corvair power and the pressures and temps have been rock solid in their ranges. I use Rotella 15W40 conventional engine oil and CamGuard and my oil analysis have been excellent. If I were running a VW engine in my plane I’d use Rotella in it as I do run it in my VW Bug (1974 model) and my 2006 Honda VTX 1800 motorcycle. It is amazing oil and I wouldn’t consider anything else.
YMMV … but I doubt it!
Dale
3.0 Corvair/Tailwheel
I’ve been plauged with 70 psi instead of the normal 40-50 psi forever. As a result I’ve really studied the type 1 oil system. The front piston controls bypass through the oil cooler, not pressure. I’ll have a post in a few weeks hopefully with a resolution to my issue.
This is great info:
thanks for the response! I have seen the concerns about vr-1 but have not changed to another , yet. still less than 100 TT. somewhere I have seen a diagram of aerovee oil system, and yes the front regulator is a bypass for cooler. if it were to stick, not much oil cooling, and maybe the extra head didnt help things. I wonder if the oil pressure sensor could/should be placed more downstrean away from the oil pump location, to display actual system pressure vs cooler inlet pressurs(?). your comments are what I am looking for with my inquirey! Thanks!
Thanks Bryan! veery good to see that I am not the only one with a bit higher O.P. I am not too concerned with the 60+ lbs in itself, but over 80 I am concerned about blowing seals, coolers,filters, lines. Nothing close to that happened as found nothing amiss when inspected after landing.. I am not sure why there isnt an alternative location( that I know of) for placement of gauge point. would that be on the top of the case, near the flywheel end? I have my hobbs sensor there just now. I need to get that oil system diagram for aerovee from my files!!!Thanks much for the reply!!
Not sure about Aerovee engines, but for the VDO senders used on Jabiru engines, maximum high readings is the failure mode of the senders.
David A.
Thanks for the reply, David! But, that ‘little’ problem with the VDO type senders is exactly why I had installed a capillary tube gauge, so I sort of ruled out a sender error as the source of my problem.
Bryan, I finally realized the Samba.com attachment was not an add, and looked at it. JUST what I needed! Printed it out, into a seperate addendem for my AeroVee book. Thanks very much for sending that!
Update! having flown for about 20 min aon the way back to my KGYI hanger, I found no problems with either high pressure…ran 65-70 psi at 190 deg… and consider that original problem root cause was sticking 'piston, in the oil cooler bypass. the fix was polishing the piston with scothbright, cleaning both the bore and other parts, lubing everything with oil, and reinstalling. The wx here north of Dallas is way too hot, hazy for my comfort level, so further flights may well be delayed some. Thanks much to all the help!
Glad to hear you got a resolution, Joe!
Thanks! But, proof is incomplete until I can actually fly more. The density altitude, temps and humidity have all been way above my limits, and consequently, I will do more flights only when…if… things actually cool down from 101 deg today!
One side effect of high oil pressure is the front plunger stays in bypass - meaning the flow is bypassing the oil cooler. I’ve been trying to figure out why my pressures have been hanging out around 70 instead of the specified 40-50. We have oil temperature problems during long climbs in the summer when 2-up.
Hi Bryan, well, my nominal pressures are between 65 and 70, maybe a bit lower when at 190 deg. My thoughts, since I never have had 40-50 lbs o.p. since new, are relative to the spring pressure on the bypass piston. I have not changed that spring length any, but if my problen continues, i will do just that, one coil at a time, very carefull to get spring to stand properly on the plug for the regulator bore.
Originally my pressures were in the high 70s and I got them into the 60s by cutting the spring down a loop at a time. The spring is pretty captive in the bore. Once I got to a certain point it didn’t seem to make any difference.
A quick update - it seems my high oil pressure was caused by blockage in my oil cooler. After checking everything else, I brought the oil cooler to the parts washer and found the solvent didn’t want to go through. It got better as I switched between the ports, and turned it around different ways. I bought a new oil cooler and my pressure was down to 52psi in cruise, but I did get to 230 F after 0.6 hours and decided to knock it off. I was at 2500’ AGL and descended at 1500 RPM, and 20-something PSI. The oil temp dropped 50F in about a minute. So I think at 52 PSI I’m still in bypass.
Thanks for the update. I sort of wonder about the bypass reliability. My cooler is a truck transmisson cooler, 300+ psi rating, and twice the area of AeroVee, there my only real concern is changes from mnormal of 180deg. my incident concerns werenot so much with temp, but with the O P going bananas. let us know how thing progress!!