Air Filter Discussion

[6643]

If it's truly a 44 pitch you're already in "extreme climb" territory. (48 is considered "normal" and 46 "climb"). What is your static RPM? Is there a "P" stamped on the prop hub, indicating it has been repitched?

[4390]

My static is about 2200 ~ 2300. The original number was 7148, the "8" was over stamped with a "4". The prop came off an Ercoupe and installed on this 120 in 2005. The log doesn't say when it was repitched.

When I picked it up in San Jose, CA it lunched off the runway and climbed like a rocket but up here in Prescott, AZ it's not impressive at all. I do fly at or near gross but the DA just kills the performance.

[6643]

My static is about 2200 ~ 2300. The original number was 7148, the "8" was over stamped with a "4". The prop came off an Ercoupe and installed on this 120 in 2005.

Curiouser and curiouser... Ercoupe props are generally 2" coarser than most planes; 7150 is "normal" for a C85. 7146 is the finest pitch I've ever encountered on an Ercoupe. (My business was Ercoupe centric.) I think I'd either leave things as they are, or have the prop evaluated by a good prop shop. Also, get your tach checked. 2300 RPM is the maximum allowed static RPM for a McCauley prop on a C85, regardless of what crankshaft you have in there, so you could already be bumping up against the limit.

[4390]

Well, I ordered a Donaldson filter and a handheld digital tachometer... I'm curious to see how the filter works and how accurate my tach is.

[4390]

Well, the Donaldson air filter showed up and I made a valiant attempt to install it but that was no joy.... The 1/4 turn bolts would snap in either one side or the other but not both.. So, back in the box. Donaldson gets an F. My handheld tach also showed up so I'll be seeing how that works tomorrow. If it works I'll check it against my panel tach.

[5099]

Well, the Donaldson air filter showed up and I made a valiant attempt to install it but that was no joy.... The 1/4 turn bolts would snap in either one side or the other but not both.. So, back in the box. Donaldson gets an F. My handheld tach also showed up so I'll be seeing how that works tomorrow. If it works I'll check it against my panel tach.

In some cases the air box suffers from time and hamhanded mechanics. I’ve seen some installations where the use of AN3 bolts and self locking nuts with washers make a better attachment.
JMHO, Steve

[4390]

Well, the Donaldson air filter showed up and I made a valiant attempt to install it but that was no joy.... The 1/4 turn bolts would snap in either one side or the other but not both.. So, back in the box. Donaldson gets an F. My handheld tach also showed up so I'll be seeing how that works tomorrow. If it works I'll check it against my panel tach.

In some cases the air box suffers from time and hamhanded mechanics. I’ve seen some installations where the use of AN3 bolts and self locking nuts with washers make a better attachment.
JMHO, Steve

Mine is totally stock, with the original Airloc's welded on, seems to have no bent flanges or damage. It's that the four air box holes are slightly wider than the four Donaldson air filter pins. You'd think Donaldson would make the holes on the filter a bit larger so there's some fudge room, but they didn't. I can't remove the pins, to enlarge the holes, since the little pin is pressed in the large pin. Since Donaldson claims to have he best service in the biz I called them, the operator sent me to someone's answering machine and I've never heard back. Again, they get an "F".