The subject of variable/controllable props has come up (again) on another thread.
What ever happened to the "McCauley 2-position controllable,hub 2B36C7,blades 78K-2"prop,per TCDS item 5? And the "Koppers Aeromatic F200-H/00-74E"prop,per item 4? I believe that Sensenich also made a controllable/variable prop that may have been approved for the 170.
Both the McCauley & Aeromatic are approved by TCDS for the A & B model 170's,but per TCDS they must have the C-145-2H engine with dampered (NOT dampened) crankshaft. I don't know about the Mac,but the Aeromatic prop does NOT require a hollow crank or anything like that for operation. It is a self-contained aperatus,so I don't know why the TCDS requires the -2H model engine. I wonder if it was a typo,& they meant to say that the installation required a dampened (not dampered) engine-- the later engines with crankshaft counterweights,as identified by a "D" in the serial number.
According to their website (http://www.aeromatic.com), Tarver Propellers in Fallon Nevada owns the rights to the Aeromatic prop line,as well as to the Flotttorp controllable (Beech-Roby) prop line. George brought up the Beech-Roby prop in another related thread. Either of these propellers might be just what the 170 needs to get all the performance possible out of the good old 145-horse Continental.
Tarver's website doesn't really indicate if he's gonna be producing these older designs again,or if he's just going to be supporting the old props already out there.
Another prop mentioned was the MT. I believe Ivo-prop also makes a controllable propeller for experimentals. I actually saw an Ivo-prop on a Cessna 140,I believe it was the ground-adjustable but it might have been the electric model. Didn't get a chance to discuss it with the owner. I'm betting it was just bootlegged on so he might be pretty hesitant to even acknowledge it was on the airplane!
Eric
propeller upgrades?
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Boy, would I like something like the Aeromatic on my 170! I agree that the props you mentioned would be just the ticket for getting that extra bit if performance we all (secretly) crave. As has been hashed out many times before, if you really want to go the "big -engine - C/S prop route", you are probably better off buying a 180, but the Aeromatic and its cousins would be ideal for a lot of the 170 crowd.
You have to wonder though, the idea sounds great, but why didn't it live on over the years? Or did the "big -engine - C/S prop route" just take over and dominate the market?
I'm happy with my 170 the way it is (well, i'd be happier if it was back together
), but I wouldn't mind just a bit more performance, especially on high DA days. I guess for now, I'll live within the limitations of my DM7653.
You have to wonder though, the idea sounds great, but why didn't it live on over the years? Or did the "big -engine - C/S prop route" just take over and dominate the market?
I'm happy with my 170 the way it is (well, i'd be happier if it was back together
), but I wouldn't mind just a bit more performance, especially on high DA days. I guess for now, I'll live within the limitations of my DM7653.Doug
Speaking of McCauly 2 position props there is one for sale at Werner Prop in Tucson the last that I knew. It came up from Bolivia and we consigned it for sale with Dennis. If I remember correctly it had an out of calander date overhaul but had not been installed. I can check it out if someone is interested. Had thought about putting it on our 171 but decided to try to go 180 CS instead.