The International Cessna^® 170 Association

George

I lost the thread about this and was wondering if you ever got back in there and enlightened us all?

Well, Dave, actually I had posed it as a rhetorical question.
The differences are not openly visible but there are differences.
Tha A series was designed for now-obsolete Eisemann, IHC and other magnetos and such but they also had other subtle differences such as minor crankshaft throw and cam differences. The most obvious difference was that A engines were typically not capable of accepting starters or most other accessories.
The C series had improved valve geometry, higher compressions, re-designed cylinders, materials differences, and could accomodate accessory cases with starters, generators, pumps, and governors.
But essentially the engines were very similar. (This question was originally posted in a "shock-cooling" discussion in another topic thread about spins.) The point of my rhetorical question was that those discussion comments were applicable regardless of whether we were flying behind an A or a C engine.
Here's another trivia question: Which "A" engine was different from all the others by accepting an electric starter, and how did it engage?

Well I answered that old post and got some of it right.

I don't know about the electric starter. I would guess that it picked up a ring gear behind the prop?

My old Chief with an 85hp and 350hrstt had the old cable operated pull starter. Because of the low time I took it apart and had it replated during the restoration of the plane. It worked pretty good but of course I seldom used it because of the chance that a kickback of the prop could rip the thing out of the plane. Even though my impulse coupling was working right.

One thing about messing around with airplanes for a mumber of years is you get to have lots of good memories right? Of course not all can be recalled all the time these days.

Good guess, Dave, but nope....not a ring gear.

Dave,is that a non-electric "cable operated pull starter" you are referring to? Would that be the "safety starter" (forget the brand name)-- some sort of Rube Goldberg lash-up to pull the prop from the "safety" of the pilot's seat?
Heard of those but never seen one. Quite a collector's item nowadays,I imagine.

Eric

Yes Eric, a long flap handle like lever by the pilots left leg with a cable going through the firewall around pullys then to an elaborate assembly bolted to the front of the engine with a disk with a pawl to pick up a 10" saw blade like thing bolted behind the prop. When I was messing with Aeroncas a lot I'd come across some here and there but a lot of them were thrown away. Never saw one installed and working other than mine because of the problems they had.

Eric/Dave...that was the "Aero-Safety Starter" and yes it worked sort of like a recoil starter on a lawnmower via a pull lever at the pilot's left leg, cables/pulley's to a rewind-spring-loaded pawl which engaged behind the prop at the flange. I still have one in my hanger somewhere that I intended to put on my Chief before I traded it, but never did.
But that is not the electric-starter in the trivia question.

George

How long are you going to keep us in suspense or are you expecting us to do the homework?

I wanted to give those interested a chance to enjoy the research.
Hint: The starter motor was made by Bendix.