Cruisair Cowl - Check Correct Installation ?
- Thread starter blimpy
- Start date
Larry Lowenkron
Member
Maybe you should find a mechanic that knows Cruisairs?
Dan Cullman
New member
FYI:
The front disc and associated padding/sealing that is immediately in back of the crank flange is meant to center and support the nose bowl.
I think the geometry of the cowling is incorrect. The crank flange should be parallel to the flat face of the nose bowl.
Another factor to consider are worn out engine mount rubbers that allow the engine to sag.
Keep working on this. It's not rocket science.
Dan
The front disc and associated padding/sealing that is immediately in back of the crank flange is meant to center and support the nose bowl.
I think the geometry of the cowling is incorrect. The crank flange should be parallel to the flat face of the nose bowl.
Another factor to consider are worn out engine mount rubbers that allow the engine to sag.
Keep working on this. It's not rocket science.
Dan
Dan Cullman
New member
Larry,
For some reason, I thought your annual had been done earlier.
Re: my post on the mount rubbers, you'll have to remove the whole cowling assembly to replace the rubbers. So do this in conjunction with the annual.
Dan
For some reason, I thought your annual had been done earlier.
Re: my post on the mount rubbers, you'll have to remove the whole cowling assembly to replace the rubbers. So do this in conjunction with the annual.
Dan
Larry Lowenkron
Member
Undo the screws holding it to the nose bowl, then as you unscrew the cowl, hold up one side but putting a piece of wire in the middle screw hole on one side and let it gently hang down as you release the opposite side. Release the wire and remove. Reverse to assemble.
Hi Larry (Blimpy)-
This is Rogers Hunter-
I haven't been on the forum in a while since I've had so much work to do.
I read that you're having a vibration problem that seems to have started with your last annual. I also read that you had a problem with a loose cylinder and manifold. You've had work done to the prop to get it into balance with no luck. I think the problem may not be the propeller. A vibrating prop makes a rapid rumble or buzz, kind of like revving an old car with a bent clutch plate. A valve or cylinder leak will make a fast shaking vibration you can really feel.
Have you checked to see if the manifold or cylinder bolts are loose again? I don't know the man and perhaps I'm being unfair but your mechanic may have left something loose here. A leaking manifold at the cylinder port will cause a lot of shaking that runs through the whole machine. My old flight school had a Cessna TR182 (SN #1!) that was vibrating a lot. They had the prop balanced five times with no luck. I went out to look at it and discovered #4 intake gasket was blown out. Put a new gasket in it and it ran smooth again. The prop wasn't out of balance at all. The engine was missing on #4 cylinder.
If no intake leaks are evident check the valve dry tappet clearance. It should be .040" for six-cylinder Franklins. There might be a stuck or deflated lifter or the mechanic may have tried to set valve clearances incorrectly. He may have assumed that the engine has solid lifters since the rocker arms have adjustment screws. This is a common error. He may have tried to reset the rockers to have clearance when they are full of oil. This will cause a lot of shaking as well.
Had a Franklin 6A-350-C1 in a Maule M-4-220C that vibrated a lot. Found two stuck lifters and the rest were all out of adjustment. Got everything freed up and adjusted to .040" dry and the owner said the engine had never run that smooth as long as he had owned it. Those lifters had been out of whack for a long time!
Glad to see you are flying. Mine is still in work. Engine runs great and I'm installing a modifed Maule airbox so I can have an air filter at my dusty airport.
Good Luck!
Rogers
This is Rogers Hunter-
I haven't been on the forum in a while since I've had so much work to do.
I read that you're having a vibration problem that seems to have started with your last annual. I also read that you had a problem with a loose cylinder and manifold. You've had work done to the prop to get it into balance with no luck. I think the problem may not be the propeller. A vibrating prop makes a rapid rumble or buzz, kind of like revving an old car with a bent clutch plate. A valve or cylinder leak will make a fast shaking vibration you can really feel.
Have you checked to see if the manifold or cylinder bolts are loose again? I don't know the man and perhaps I'm being unfair but your mechanic may have left something loose here. A leaking manifold at the cylinder port will cause a lot of shaking that runs through the whole machine. My old flight school had a Cessna TR182 (SN #1!) that was vibrating a lot. They had the prop balanced five times with no luck. I went out to look at it and discovered #4 intake gasket was blown out. Put a new gasket in it and it ran smooth again. The prop wasn't out of balance at all. The engine was missing on #4 cylinder.
If no intake leaks are evident check the valve dry tappet clearance. It should be .040" for six-cylinder Franklins. There might be a stuck or deflated lifter or the mechanic may have tried to set valve clearances incorrectly. He may have assumed that the engine has solid lifters since the rocker arms have adjustment screws. This is a common error. He may have tried to reset the rockers to have clearance when they are full of oil. This will cause a lot of shaking as well.
Had a Franklin 6A-350-C1 in a Maule M-4-220C that vibrated a lot. Found two stuck lifters and the rest were all out of adjustment. Got everything freed up and adjusted to .040" dry and the owner said the engine had never run that smooth as long as he had owned it. Those lifters had been out of whack for a long time!
Glad to see you are flying. Mine is still in work. Engine runs great and I'm installing a modifed Maule airbox so I can have an air filter at my dusty airport.
Good Luck!
Rogers
blimpy
New member
Larry, Yes ! Dan Torrey will do my annual soon.
I have been consulting with him.
Good News !
Pulled the cowl, 3 of the 4 motor mounts look undamaged and are "soft"
when probed with a finger nail. One by the fuel pump is difficult to inspect.
Pulled the rocker covers, and checked all the valves for normal operation.
All are free and working fine.
Put the prop on, and test ran the engine with the cowl off. Minimal vibration all rpms.
Squared up top support for the nose cowl support disc - found it was canted backwards
presumption is that it tilted while being torqued, and the mechanic didn't notice.
Put the cowl back together carefully, and installed the prop yet again.
Test run showed minimal vibration at all rpm from idle ( 600) to static full throttle 2525 rpm.
So ends a month long saga of speculation, finger pointing, expense, and yada yada.
Like SoCal Plane Doc said " at least you get to work on your airplane ".
And what a learning experience it has been !
No matter how many times I may have read the manual, I just didn't grok how the cowl really works,
and goes together with the rest of the airplane, until I'd taken it apart and put it back together a couple of times.
:roll:
It will be very good to have Dan get a good close look at every inch of this airplane.
I expect to discover that some of the stuff I have been worrying about isn't really important at all.
Fingers crossed he doesn't find anything important that I've missed. But that's why I'm hiring him.
Meanwhile I can devote my self to the minor painting and patching work and other stuff spelled out for pilots
to do in the FAR's.
I have been consulting with him.
Good News !
Pulled the cowl, 3 of the 4 motor mounts look undamaged and are "soft"
when probed with a finger nail. One by the fuel pump is difficult to inspect.
Pulled the rocker covers, and checked all the valves for normal operation.
All are free and working fine.
Put the prop on, and test ran the engine with the cowl off. Minimal vibration all rpms.
Squared up top support for the nose cowl support disc - found it was canted backwards
presumption is that it tilted while being torqued, and the mechanic didn't notice.
Put the cowl back together carefully, and installed the prop yet again.
Test run showed minimal vibration at all rpm from idle ( 600) to static full throttle 2525 rpm.
So ends a month long saga of speculation, finger pointing, expense, and yada yada.
Like SoCal Plane Doc said " at least you get to work on your airplane ".
And what a learning experience it has been !
No matter how many times I may have read the manual, I just didn't grok how the cowl really works,
and goes together with the rest of the airplane, until I'd taken it apart and put it back together a couple of times.
:roll:
It will be very good to have Dan get a good close look at every inch of this airplane.
I expect to discover that some of the stuff I have been worrying about isn't really important at all.
Fingers crossed he doesn't find anything important that I've missed. But that's why I'm hiring him.
Meanwhile I can devote my self to the minor painting and patching work and other stuff spelled out for pilots
to do in the FAR's.