Bargain (?) Cylinder overhaul also C-75 conversion

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Champ Dreamer
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Joined: Thu Mar 20, 2008 00:14
Location: Colorado Springs
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Bargain (?) Cylinder overhaul also C-75 conversion

Post by Champ Dreamer »

There is a guy in Florida advertising cylinder overhaul on Barnstormers for $125 plus parts. Has anyone had any experience with him? Sounds too good to be true, but I'm thinking about sending him a cylinder and see what happens. Also, I have aquired a C-75-12 that I want to convert to a C85-12. The only difference in the engines is the carb venturi and metering jet, plus paperwork, of course. Has anyone out there done this? My IA and I are thinking we might be able to do it with a 337.
Continental says they "no longer support this conversion". Wouldn't say why, but didn't say there was a problem with it. I can buy a new data plate from the folks at Fresno.

Thanks,
Brian Walker
7AC with C-75, soon to be C-85
Larry
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Re: Bargain (?) Cylinder overhaul also C-75 conversion

Post by Larry »

Get copies of Continental Service Bulletin M47-16 and M65-14. Look at M47-16, page 11, which details the part changes to convert a C75-12 to C85-12. Continental Service Bulletin M65-14 provides guidance on re-stamping the engine data plate from one engine model to the next. These are old Continental Motors documents that TCM (new company) does not list in their SB index.

These two documents provide conflicting guidance for FAA approval. M47-16 specifically states that the FAA needs to approve the data plate change, whereas M65-14 seems to approve simply re-stamping the data plate with no additional FAA approval. Your I.A. will need to work his way through that with the FSDO PMI. The FAR's have been updated several times since 1947 regarding data plates, so that might be the final word. See FAR 45.13 (d)


Larry Clark
ATP/A&P/I.A.
7AC/BCM N84096
Champ Dreamer
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Re: Bargain (?) Cylinder overhaul also C-75 conversion

Post by Champ Dreamer »

Larry,

Thanks so much for the valuable information. I found M47-16 on the Sky Ranch site (boy, do I love their Engineering Manual) but I've been unable to find M65-14. Any idea where I might get a copy?

Thanks again,
Brian Walker 7AC NC1197E
Larry
Posts: 67
Joined: Sun Aug 31, 2008 15:43
Location: Tucson, Arizona
Contact:

Re: Bargain (?) Cylinder overhaul also C-75 conversion

Post by Larry »

Brian:

I got a copy from Todd at the aeronca.com web site several years ago. You might also contact Harry Fenton. Harry is a wealth of information about the old Continental engines.

http://www.bowersflybaby.com/tech/fenton.htm#a65-O200

Also you might try to find a copy of SB M87-18 and M75-6. Some of these have R1 or R2 revision numbers on the end of the manual number. These also are related to this subject. The current TCM SIL00-9A covers Engine Data Plates.

Good luck with your conversion.

Larry Clark
ATP/A&P/I.A.
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