Doyn Conversion

melcessna · Post by **melcessna** » Thu May 17, 2007 12:48 am

I am looking for information regarding the Doyn conversion. I know the company is defunct, however does anyone have the conversion and related paperwork? Specifically, I'm looking to see if a vaccum system is part of the conversion. Conversely, if someone knows of an STC or has a field approval for a vaccum system I'd be most interested, also. Any help is appreciated. Thanks so much. Mike

blueldr · Post by **blueldr** » Thu May 17, 2007 2:08 am

What the hell! If you want a vacuum pump, go ahead and install one. Who's to know it wasn't always there. Nobody knows anything about the Doyn conversion anymore anyway. It used a bastard Lycoming O-340 engine which was a stroked out (.200") O-320. It didn't amount to squat, so they stroked it out another .300" and made the O-360.
When they were all finished, the damn thing was still a Lycoming!

Post by **GAHorn** » Thu May 17, 2007 2:42 am

http://cessna170.org/phpBB2/viewtopic.p ... t=venturis

Lots have been cussed/discussed about vacuum systems here.... this is one of them.

c170b53 · Post by **c170b53** » Thu May 17, 2007 4:53 am

Mike looks like you just joined the on-line thing, welcome. Lots of info here , just use the search as Gahorn was just hi-lighting past posts. I have a Doyn 0-320 C/S and I run a vaccum pump the rear case. Works great. Oh by the way you'll see various opinions on everything. Conversions are no longer available from Doyn, you will have to use H.Dicklers conversion should you wish to go down that path with the Lycoming. I'm sure you have an opinion as well, don't hold back.

Post by **GAHorn** » Thu May 17, 2007 5:24 pm

Jim...is that H. Dickler?? Or Harry Dellicker (of Porterville, California)?

c170b53 · Post by **c170b53** » Fri May 18, 2007 3:51 am

Ooops again. Thanks for the correction George