Oil Pressure in A65-8

gusc · Post by **gusc** » Tue Nov 28, 2006 21:05

Thanks Guys, these are all really good ideas.

What I had planned to do was just run it up to high power on the ground and see if anything happens. Unfortunately I don't have it at a nice big airport, just on my farm with hazards at both ends and not a lot of places to set down if something happens on takeoff. Not the best conditions.

I have a borescope so I'll take a look at the cyl walls but I'm optimistic because it never did make any unusual sounds, just purred as per usual. I do have an AI friend nearby who could look at it. In fact he has my borescope now so I should be able to get him to look at it. I know roughly what to look for but would feel better using his skills.

I presume that scored walls would be from rings since the pistons and pin plugs are not hard enough to score steel?

I changed the oil and cleaned the screen just after the no press problem and found no metal, just some carbon flakes - so that is a good sign. I changed the oil because I thought the straight 50W was too thick and was causing the problem. I guess it would be a good idea to check the screen again after checking the cyl walls and giving it a good high power runup.

Unfortunately I don't have a base oil analysis yet because I just have only about 7 hrs on it since I got it with fresh oil. I have three or four unused analysis kits left over from the Navion which I will use.

Nobody said anything about crankshaft clearance? Shouldn't this help determine if there is any bearing problem? Since it only has 120 hrs since major I would think that a bit of abnormal bearing shouldn't be a problem as long as none have rotated.

Again, thanks for all the info. If you guys hadn't told me about A65 oil pumps I would still be thrashing around in the dark. I was completely convinced that this was a gage problem because it happened all at once.

gusc · Post by **gusc** » Thu Dec 07, 2006 01:10

I finally got my AI to check the engine today and the good news is that there is no sign of cyl wall scoring and the crank runout is as it should be, plus there is no "tightness" whatsoever when turning the prop over, there never was.

Next comes a good runup, an oil screen check and an oil sample sent in for analysis. The analysis probably won't be much help now but it will establish a baseline.

After all this it is time to fly!!

The bad part is that I unscrewed a bottom spark plug bushing and found an exhaust/cyl leak. Well, maybe that last part was good and not bad.