I've got an EA82 with Delta cams. I'm having inconsistent compression issues and I'm thinking it's because some of the lifters are not pumping up. I started out with all new lifters and I had great thrust numbers.... for a while. Eventually I noticed I wasn't getting the climb rate I once was. I did a thrust test, and one cylinder was 115 psi when the others all showed 180 psi.
I changed the lifters in that cylinder and got the compression back. It only took a flight or two before the lift issues came back. Another compression test showed 90 psi in two cylinders and 175/180 in the other two. I've replace a few of the lifters again, letting them soak in oil for 5 days and pumping them while submerged before installing them. they seem to not be pumping up.
I'm not having any blow-by or oil consumption so I'm pretty sure the rings are good. My oil pressure starts out at 60 psi when cold and will go to just under 40 psi when hot.
The lifters I've been using are not OEM, but they do seem to be nicely built. The OEM lifters are $73 each whereas the aftermarket ones are about $10 each.
I'm going to buy one of the OEM lifters to test to see if I has an issue pumping up like the others. If that fixes the issue, then I'll buy a whole set of the OEMs.
I am running the #10 stainless washer behind the lifters at Delta cams request.

Does anyone have any suggestions as to what I might be missing?


Bobby Munroe
AirCommandPilot on the RWF.
Houston, TX (Anahuac, TX)
Lone Star Rotorcraft Club (Vice President)

Gday Bobby,
I can only think of two possibilities. Check that the oil hole in the lifter lines up with the oil pressure feed channel in the block throughout the full lifter travel, and also a leak in the oil suction line to the oil pump can introduce air into the system and that sure makes lifters carry on like a loose tappet.
Having said that hydraulic lifters have a small range of travel and I’d be surprised if they caused that much loss of compression, even if they had leaked down. If they pumped up too far then that would be more likely to cause a large compression loss.
Tim

I'm picking up another EA82 today for parts, maybe I'll be able to salvage the OEM lifters, and get the micrometer out to compare the lifter pockets with mine. I guess it's possible the oil hole isn't lining up. I'll take a look.
I might have a line on a running EA81 from the same guy. Would the 81 be a better choice? Is the weight savings significant?

The EA82 is a good engine, but in my opinion the EA 81 is a better choice. It is simpler, lighter and developed similar HP at equivalent RPM’s. Opting for a higher revving engine is not conducive to engine reliability and life. I can relate to a couple of EA81’s with 3000 hours with several over 2000 hours. 99% of EA81 problems were operator/reconditioner caused.
The problem nowadays would be to find a good low hour EA81

No luck on the 81, but I did pick up an 82 last night. I took the cam towers and heads off. The bottom of the lifter pockets look better than mine. I think I'll have these heads rebuilt and may swap them out onto my engine.
The engine number on the case is 711541. Anyone know what year/model this is from?