High Oil Temperature
Forum rules
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
-
6643
- Posts: 2612
- Joined: Tue May 01, 2018 7:00 am
- Name: John C
- Location: KLCI, NH
- Aircraft Type: 1946 C140/C90
- Occupation-Interests: A&P, semi-retired
- Contact:
Re: High Oil Temperature
I have to agree, if the only thing that changed was the mags then it must have something to do with ignition.
John Cooper
www.skyportservices.net
www.skyportservices.net
-
V529
- Posts: 621
- Joined: Tue May 01, 2018 7:00 am
- Name: Victor G
- Location: Michigan
- Aircraft Type: C-120
- Occupation-Interests: Work on airplanes till the cows come home..........they're still out.
- Contact:
-
edidin
- Posts: 177
- Joined: Mon Jul 19, 2021 8:57 pm
- Name:
- Aircraft Type:
- Occupation-Interests:
- Contact:
Re: High Oil Temperature
Trust but verify your mechanic's timing with the new mags. Also check that all the leads are going to the correct plugs and/or are in good condition. On the little Continentals, one mag fires the top plugs, the other the bottom. And they are two degrees off in their firing BTDC in the C-85.
It's really the only thing that you touched that could affect temps based on the actions in the orignal post. This assumes that historically your oil temps were the standard OAT + 100-110 degrees F.
It's really the only thing that you touched that could affect temps based on the actions in the orignal post. This assumes that historically your oil temps were the standard OAT + 100-110 degrees F.
-
2718
- Posts: 8
- Joined: Tue May 01, 2018 7:00 am
- Name:
- Aircraft Type:
- Occupation-Interests:
- Contact:
Re: High Oil Temperature
Findings/Solution:
1. Large baffle between #1 and #3 flopping up and down/Tightened up w/safety wire.
Oil temp dropped from 225 to 210.
2. Small baffle between #2 and #4 bent.
3. Support plates worn.
4. Replacing all baffles and support plates. Spring clip availability and price questionable.
5. May add blast tube in the future.
Amazing how critical/sensitive the intercylinder baffles are.
Huge thank you to John Cooper and his initial suggestion.
1. Large baffle between #1 and #3 flopping up and down/Tightened up w/safety wire.
Oil temp dropped from 225 to 210.
2. Small baffle between #2 and #4 bent.
3. Support plates worn.
4. Replacing all baffles and support plates. Spring clip availability and price questionable.
5. May add blast tube in the future.
Amazing how critical/sensitive the intercylinder baffles are.
Huge thank you to John Cooper and his initial suggestion.
-
edidin
- Posts: 177
- Joined: Mon Jul 19, 2021 8:57 pm
- Name:
- Aircraft Type:
- Occupation-Interests:
- Contact:
Re: High Oil Temperature
Just chiming in to check the timing again - trust but verify. Your mechanic's 140A had a C90 which has slightly different timing from the C85. According to TCDS (check this of course), C90 is 26 degrees Top, 28 degrees Bottom; C85 is 28 degrees Top, 30 Degrees bottom. On all the small Continentals one mag fires the top plugs and the other the bottom plugs.
Basic rule is that a C85 runs OAT +100-110 degrees. So at 70-80 should be around 190 at most (and likely lower).
Basic rule is that a C85 runs OAT +100-110 degrees. So at 70-80 should be around 190 at most (and likely lower).
-
2718
- Posts: 8
- Joined: Tue May 01, 2018 7:00 am
- Name:
- Aircraft Type:
- Occupation-Interests:
- Contact:
Re: High Oil Temperature
Thanks.
Checked timing twice. It is correct. Even tested spark plug leads.
No ignition issues.
Checked timing twice. It is correct. Even tested spark plug leads.
No ignition issues.
-
6643
- Posts: 2612
- Joined: Tue May 01, 2018 7:00 am
- Name: John C
- Location: KLCI, NH
- Aircraft Type: 1946 C140/C90
- Occupation-Interests: A&P, semi-retired
- Contact:
Re: High Oil Temperature
Not to beat a dead horse, but, left mag (as seen from the pilot's seat) fires all four lower plugs and is timed at 30 BTDC, right correct?
John Cooper
www.skyportservices.net
www.skyportservices.net
-
2718
- Posts: 8
- Joined: Tue May 01, 2018 7:00 am
- Name:
- Aircraft Type:
- Occupation-Interests:
- Contact:
Re: High Oil Temperature
Hellow John,
If anyone has a right to beat a dead horse it is you.
Left mag firing lower plugs at 30 degress and right mag firing top plugs at 28.
Thanks again!
If anyone has a right to beat a dead horse it is you.
Left mag firing lower plugs at 30 degress and right mag firing top plugs at 28.
Thanks again!