Thorp Air Command - T18.net

Has anyone ever put a 6 cylinder Lycoming in a T-18?
I've been looking at O-435-A direct drive engines (Cheap!) and wondering. They have a Conical mount like a narrow deck Lycoming 4 cylinder.
They have rear mounted generator and starter, which moves the CG aft and offers the possibility of a slick forward cowl.
And the engine rebuild could include boring the case for O-320 cylinders, creating an O-480, promising 50% more power than an O-320...240 HP!
No constant speed props! but weight & Balance wouldn't permit a heavy prop so it's a moot point.
Any comment?

_________________
Scott Emery
EAA Chapter 326
T-18 N18TE

What does a 435 weigh? What is the new VNE going to be? Sure would climb tho!

The o-435 is basically a 6 cylinder O-290. There were a lot of these engines in Stinsons. They are a very heavy engine. I seem to remember they were in the 450 lb range.

Jim

http://www.fokkervliegen.nl/Parts%20Cat ... -435-A.pdf
Using this parts manual, I see the O-435 is very different than an O-290 in the accessory case, the case nose and the sump. Also the exploded diagram of the crankcase shows the crankshaft thrust bearing to be a ball bearing in the nose.
The worst appears to be the rear mounted starter, which looks like the starter on my 1957 Ford tractor. Weighs a ton and would interfere with the firewall. The same for the generator. A small alternator would probably be easy, I'm scratching my head about adapting a lightweight geared automotive starter...
The oil sump is long, HUGE and a heavy wall casting.
Lots of potential to reduce weight....at great cost of man-hours and material doing it myself. Because no one could afford the time and material to hire this out. All to preserve the Conical Engine Mount
A lightweight O-540 235HP on a new engine mount would be more expedient.
Truth be told, I've been working to enhance my T-18 with it's O-290, which is low time and runs well. I just went down a mental dead end. I'll press-on with the work I have.

_________________
Scott Emery
EAA Chapter 326
T-18 N18TE

I guess I should have said the O-435 uses 6, O-290 sized cylinders.

Jim