sump oil screen failure

[n502pd]

Just a quick note on my findings at the 10 hour oil change yesterday. I do pull the oil screen out to examine for any particles large enough to have a part number on them(ha ha!) and to look at oil itself.The oil looked clear and had no real outstanding particles..some carbon and one or two Al flecks was all. After examining the screen, I noticed that the center section was still in the engine on the pickup tube. The screen is assembled with a rivet in the center, holding the large outer part together with the inner adapter that fits on the pickup tube. That rivet had been loose for a while since the last oilchange, and had wobbled out its hole (why??) and had come loose, or so it looked, probably on the last flight on that load of oil. On that last flight, the oil pressure AGAIN took off for the high end,(above 85psi) (monitored with capillary tube instrument at front hub area) but this time I caught it on down wind approach, and landed (not my best) as quickly as I could. I looked closely and found the initial rivet was much smaller than the hole in the two peices, and was not squashed (set) properly. The wobbled out hole had exceeded the diameter of the set on the rivet. I was concerned as this was an original Aerovee kit component. I did find another source (Beck-Arnley # BA-041-0700, around $9 at ORielys auto parts) and was astonished that the new one was very much better quality and appeared to be more robustly constructed, with a properly set rivet . I got two.

Investigation the oil pressure regulators, I did find particles that appeared to be aluminum making the rear most regulator piston stick again. The front regulator piston didnt appear to have any particles. I repolished them both with scotchbright, cleaned all places I could reach, reassembled with lihium grease, added oil and ran it up for 15 min at varrious rpms. All normal again. What I dont understand just yet is why the regulator pistons appear to only stick at the top,( this is second accurance) and not further down to allow for lower than normal oil pressure?

So, my suggestion to whomever is interested is to take a close look at your screen, and make sure nothing is loose where the revit is. This is what I think, at this time, is the cause of my sticking regulator piston, other than them being quite new and maybe not broken in.

Has anyone else noticed this bad rivet job on the screen? Were there any other problems noted, say with oil pressure regulator sticking? Unexplained aluminum particles in the oil? ( I do realize pistons will shed small particles while they get broken in).

Joe

[jeff0196]

Joe,

Good to hear that you've been doing some flying and putting time on your plane. There is no way for me to stress strongly enough about addition of an actual oil filter for your engine. It sounds like you've already found your own unique reason for it. If you would like more information on why and how, please PM me about it.

To answer your question about the rivet, I remembered reading this thread in the past, check it out:http://www.sonexbuilders.net/viewtopic.php?f=7&t=2367

-Jeff

[n502pd]

Thanks for the link to the earlier stuff. I was not paying attention durring that time as I had yet to order the engine and missed that thread. Oh well, some days are new days for some people!

I am most interested in what you have to say about the oil filter. PM to follow!

[floridasonex]

Joe,

Good to hear that you've been doing some flying and putting time on your plane. There is no way for me to stress strongly enough about addition of an actual oil filter for your engine. It sounds like you've already found your own unique reason for it. If you would like more information on why and how, please PM me about it.

To answer your question about the rivet, I remembered reading this thread in the past, check it out:http://www.sonexbuilders.net/viewtopic.php?f=7&t=2367

-Jeff

I'd like to comment on oil filters. On my original build I installed an oil filter in series with the cooler from the
ports on the stock full flow pump. It blew the filter even though I let it warm up sufficiently. I ran without
one for a few years. On another occation I blew the cooler in flight right after takeoff. Again ... i let it
warm up to 100 deg plus. At that time I installed a thermostat bypass valve before the cooler. Problem
solved. Recently I went back to a remote filter. This time installed behind the bypass valve inline with
the cooler. I used an HP-1 racing filter. I also made a new adapter plate and took the cooler/filter circuit
off the adapter plate .. where the stock VW top cooler mounts. I just looped output to input on the full
flow pump until I can get one without the ports. Not only has my oil pressure been more stable (low 50's at
cruise), it substantially reduced wear metals floating around in the oil. When I sent the sample to Blackhawk
they commented on the results asking about the drastic reduction. I agree with Jeff wholeheartedly on the
value of a real filter and not just relying on the screen. I moved the OP sender to the stock port on the
right side of the block.

RT

[Onex107]

I'm not knocking oil filters. They are a better/finer filter than a screen. But, this is a fact, the O-200 Continental in my Cessna ran for 2500 hours over 35 years on a screen. I did oil analysis every 25 hours which is a good way to keep tabs on the health of your engine. Never saw anything but carbon flakes on the screen. At over haul the crank and cam did not need grinding. Just bearing and ring replacement. I think the 25 hour oil change is better than a 50 hour W/ filter. And, I believed the Cessna guru who says you should not return crankcase vent oil to the crankcase. That 1965 Cessna 150 is now down in Texas still doing it's thing and I'm running an Aerovee the same way. Just saying.

[floridasonex]

I'm not knocking oil filters. They are a better/finer filter than a screen. But, this is a fact, the O-200 Continental in my Cessna ran for 2500 hours over 35 years on a screen.

Do you suppose there's any difference in parts and machining quality between a Continental and our
dune buggy motors?

RT

[n502pd]

I tend to agree about the Contenental oil screens and 25 hour changes. returning vented oil to the sump, I am not so sure of, but do have that setup on N502PD, and have yet to see and
real oil usage. Just a bit on the belly after 10 hours, but not much.

On the other hand, the filter explosions interest me as I have just flown for the first time with a filter installed. For those who have had a filter fail, what filter brand and part number filter was used? I am using Fram HP3 racing filter for dragsters,(what dose that mean??!!) and it is made out of much thicker metal. If I remember the spec sheet, it is rated for 500 psi? A turbo Waiex friend nearby has used these for a good number of years and has reported no problems. I would be pleased if I could find a local source at a cheaper price than $15 plus shipping. My oil pressure behaved itself throughout the 25 min flight, at cruise rpm of 2900 thru max firewalled at 3250+rpm. I was impressed with it staying at 68 psi. The oil wasnt really as warm as I would have liked (forgot to install the winterization kit).

Merry Christmas to all!