The International Cessna^® 170 Association

3958v · Post by **3958v** » Mon Jan 25, 2016 2:48 pm

I have had 2 cams go bad in 1000 hrs on my C145 and was wondering how common a problem this is. The first one went bad after the engine sat for some time but the second one a brand new one with new followers only lasted 600 hrs. This time the problem is on the front lobes may or may not be significant. Bill K

c170b53 · Post by **c170b53** » Mon Jan 25, 2016 4:05 pm

Was the cam for a front cylinder? Was it the same cam lobe? Just wanted a few more details before throwing my dart

blueldr · Post by **blueldr** » Mon Jan 25, 2016 7:53 pm

It almost sounds like a lack of lubrication on that part of the cam, but would the haudraulic lifter unit even pump up if the lube was somehow blocked off?

ghostflyer · Post by **ghostflyer** » Mon Jan 25, 2016 10:51 pm

Did some one check the push rod length and part number .

3958v · Post by **3958v** » Fri Jan 29, 2016 12:51 am

The lobe that went was the same on both cams. Blueldr might be on to something with the lifter as the engine sometimes would run slightly rough for a few miniutes after start up. I could never put my finger on the roughness as it was not related to the mags as it was slightly rough on right, left or both. I dont have the second cam out but I checked the first one and the lobe that was starting to go was 5 thousanths under the other lobes. The lobe was the front lobe. Bill K

c170b53 · Post by **c170b53** » Fri Jan 29, 2016 1:10 am

Number six cylinder would have been my guess. How did you know you had an issue?

3958v · Post by **3958v** » Fri Jan 29, 2016 1:22 am

The mechanic found the problem while changing out a cylinder with low compression. Have you seen more problems with # 6? Any recomendations for avoiding this in the future. Changing cams too often takes a lot of the fun out of flying!!!! Bill K

hilltop170 · Post by **hilltop170** » Fri Jan 29, 2016 3:42 am

I wonder if front cam lobes going bad is a generic Continental 6-cylinder problem? I had the same thing happen to the front 3 lobes on the O-520 in my C-180 at 1000hr smoh. There were no symptoms and were found on removal of Millenium cylinders for a mandatory AD.

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3958v · Post by **3958v** » Sun Mar 27, 2016 12:30 pm

Finally got back in the air today. So far very happy with the job Aero Engines of Winchester VA did on my engine. He recommmended regrinding my cam as he felt that it was better than a new one. While the 170 was down I got a chance to fly in a Cherokee 235 and a 172. Have to say I would much rather fly our 170s!!! Bill K

The International Cessna^® 170 Association

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