[rv6asailer]

I built a very nice RV6A which has about 300 hours on it. For the first 5 years the engine was flawless and oil pressure was 80lbs solid, but about 2 years ago I noticed a gradual drop in oil pressure when hot and I am now running about 63 lbs at 170 ? 180 deg and I do not feel this is right so I install a mechanical gauge and verified the gauge was good then pulled the engine and had a rebuild shop do a look over, other than finding one lifter starting to spawl they felt all I needed were some washers (3) and new lifters. I replaced all the lifters with factory new and said buy to $2800.00. put the engine back in and the pressure was worse by a few pounds. After checking for cracks, scratches and such in the over pressure seat I decided to split the engine (dreams of bearings coming apart prompted this). I took the engine to a different shop and we split the engine, what we found surprised me... nothing. The engine was pristine inside, a visual of the cam showed no wear and the bearings looked good. We measured the cam, and crank and they were in speck. The oil pump also looked good. Because of a small defect in one rod bearing we decided to replace all 4 rod bearing sets, new over pressure spring and ball and resembled and off I went. Got a deal on this, just $800 for all.

Now were back at the plane and nothing has changed?

What we have done:

New oil Pressure Gauge Plus added Mechanical Gauge
New lifters
New over Pressure Spring and Ball
Inspected Cam & Crank
Inspected Oil Pump

Wheres my pressure going? Any Thoughts

Cold Start ( outside air 70 deg) ? idle > 55 lbs ?. 2000 rpm > 75lbs
Hot 170 deg - idle > 38lbs ?.. 2450 rpm 60 ? 63 lbs

Markings Red ? 25lbs ?. Yell 26 ? 60 lbs ?. Green 61 ? 95lbs

I want to sell the plane but feel I cant until this is fixed. I will take offers though.

http://home.comcast.net/~collinsj57/site/

 

[PerfTech]

I built a very nice RV6A which has about 300 hours on it. For the first 5 years the engine was flawless and oil pressure was 80lbs solid, but about 2 years ago I noticed a gradual drop in oil pressure when hot and I am now running about 63 lbs at 170 ? 180 deg and I do not feel this is right so I install a mechanical gauge and verified the gauge was good then pulled the engine and had a rebuild shop do a look over, other than finding one lifter starting to spawl they felt all I needed were some washers (3) and new lifters. I replaced all the lifters with factory new and said buy to $2800.00. put the engine back in and the pressure was worse by a few pounds. After checking for cracks, scratches and such in the over pressure seat I decided to split the engine (dreams of bearings coming apart prompted this). I took the engine to a different shop and we split the engine, what we found surprised me... nothing. The engine was pristine inside, a visual of the cam showed no wear and the bearings looked good. We measured the cam, and crank and they were in speck. The oil pump also looked good. Because of a small defect in one rod bearing we decided to replace all 4 rod bearing sets, new over pressure spring and ball and resembled and off I went. Got a deal on this, just $800 for all.

Now were back at the plane and nothing has changed?

What we have done:

New oil Pressure Gauge Plus added Mechanical Gauge
New lifters
New over Pressure Spring and Ball
Inspected Cam & Crank
Inspected Oil Pump

Wheres my pressure going? Any Thoughts

Cold Start ( outside air 70 deg) ? idle > 55 lbs ?. 2000 rpm > 75lbs
Hot 170 deg - idle > 38lbs ?.. 2450 rpm 60 ? 63 lbs

Markings Red ? 25lbs ?. Yell 26 ? 60 lbs ?. Green 61 ? 95lbs

I want to sell the plane but feel I cant until this is fixed. I will take offers though.

http://home.comcast.net/~collinsj57/site/

... One possibility is that the first gauge was wrong from the start and it took it all this time to break in and read correctly. That would explain it all! if you have made no other changes like cooler, vernatherm, filter adapter, oil or filter type this is all there is. Allan...

 

[fixnflyguy]

I have an H2AD in my -4 that I did a full rebuild on...it has about 200 hrs on it and has been rock solid 95 psi cruise since day one. Very similar to your earlier readings, and with all you have done, it seems something simple is being missed. A couple months ago I think one of the Team Aerodynamix guys had a similar problem and replaced the pressure regulator spring, as it had fatigued. I would like to know the fix if it clears, as inquiring minds (and H2AD owners) must know. I will look for the thread, and though he didn't have an H2, the oil pressure stuff is all the same.

 

[jrs14855]

oil pressure

Connect a mechanical gage to the right front port of the main oil gallery. The reading there is around 10 psi less than the port at the rear. This will tell if you have a partial blockage of the port or fitting at the rear. If the reading at the front is as it should be I would install a new oil pump.