diagnostic dillema

[DWood]

Even a blind squirrel can find a nut once in while

[GAHorn]

Even a blind squirrel can find a nut once in while

Only with a good website forum!
http://www.findnuts.com/

[DWood]

George:
That is quite a website and it would be absolutely perfect if they also sold 170 parts. Nothing better than peanuts, popcorn, and 170's.
Thx,
Dan

[krines]

We suspected an intake leak from the beginning but with cylinders 4 and 6 being colder it did not make sense as they should have been hot due to leaning. Not getting a boost from the ether threw us off as well but it was hard to direct the spray at the leak. This was a large leak as 1/3 of the gasket was not creating a seal. Also I was flying this thing and picked up 7 to 10 mph at 2400 rpm. Steve

[DWood]

Can you explain how 1/3 of the gasket on the intake elbow "came out". Did the mechanic miss the stud when they installed it, use an old gasket, or what? I am glad that you got it fixed!

[cessna170bdriver]

We suspected an intake leak from the beginning but with cylinders 4 and 6 being colder it did not make sense as they should have been hot due to leaning. Not getting a boost from the ether threw us off as well but it was hard to direct the spray at the leak. This was a large leak as 1/3 of the gasket was not creating a seal. Also I was flying this thing and picked up 7 to 10 mph at 2400 rpm. Steve

The leak on #2 probably put cyls 4&6 lean of peak (cooler).

Miles

[krines]

Dan, My mechanic must have torn it on install it was a new gasket and he admits it. Didn't charge me to pull everything including the new points and condensers in both mags. I would have had to do the mags next annual. And I got to experience flying the 5 cylinder version of the 170 which few have done. Only 1 aborted takeoff on the 5000 ft but it was OK on the 10000 ft . Steve

[DWood]

Steve:
I was just curious how this could happen so we all can learn what not to do. I am glad you are flying safely and happy.
Thx,
Dan

[GAHorn]

Some installers use a bit of gasket compound on the intake elbow and lay the gasket on that, hoping to keep the gasket in-place while the elbow is slid into-place....but the hazard is that one of the studs will catch the gasket and dislodge it. In some instances it is virtually undetectable as the gasket is not dislodged externally...but INTERNALLY and cannot be seen except with a mirror and some very keen eyes viewing from the pushrod-tube side.
It's best to install the gasket on the studs then put the elbow in place.

[Brad Brady]

It's best to install the gasket on the studs then put the elbow in place.

intake elbow.JPG

Exactly and a thin coat of tight seal to hold the gasket on the cylinder doesn't hurt either....Brad

[krines]

The injury occured just as described by gahorn. A complicatiing factor was the cylinders were installed 6-4-2 in order making it difficult to inspect the 2 cylinder afterwards due to the confines of the rear baffle. Installing the intake elbows prior to attaching the cylinders will allow complete inspection. Steve