85 HP Mod

[champ81L]

I'm writing this on behalf of an older friend who hasn't joined the computer age yet. He is restoring a '46 TCraft that he bought as a project. It came with an STC to hang a 85 HP continental up front. He says that according to the STC he must use a engine mount that is about 6 inches longer than the one for a A65, which creates all kinds of problems.

The engine will fit on the 65 mount, so why can't he use it? Anybody have any info on this?


BTW: Last summer I replaced the 65 with an 85 in my champ. I built up the 85 using the STC that allows installation of crank, pistons and c-rods from an 0-200. The engine went on the same mounts with virtually no modifications required. The performance compared to the 65 is awesome!

Tim Juhl

[NY86]

Re: 85 HP Mod

Originally posted by champ81L
The engine will fit on the 65 mount, so why can't he use it?

simple answer: 'Cuz the STC says to use the other mount.

Any deviation from the STC will require a field approval. You'll have to prove that structurally, CG wise, cooling wise, etc, etc, etc, it all works out.

[Forrest Barber]

Actually the full STC calls for the -4 mount so he can have starter & generator. Plus it allows for the #1500 gross wt.

You do not have to use the full STC . Call the STC holder and seek his advise. I think your friend wants to convert his ship to a BC12D-85 ( No STC necessary) ; short mount & 1280 Gross unless he wants to stay with #1200.
The STC will be good "acceptable" data and the IA can use it to work with the FSDO to achieve the end purpose.

[Rich. Anderson]

85 mod

I have had a field approval on a 85 installed for about 40 years. No change to engine mounts, etc. Same propellor. Gets me up to 8 to 12,ooo feet when needed in the Rocky Mountains.

Go for it.

[stormman]

Rich is right
can't use a starter though