Bill,
If the asking price were $25 - 30K I'd consider it.
The 336 Blowsuck (336 was the Skymaster, 337 was the Super Skymaster) was numbered that way because the last production push-pull twin of note was the Dornier 335, the fastest piston engine fighter of WWII and, yes, the guys at Cessna specifically did not use the 335 number for that reason. (About 10 years later the 335 number was used for the unpressurized 340.)
The 336 was a pretty good concept, although it was a blow to sales when the FAA did not allow single engine rated pilots to fly them, and insisted on a multi-engine rating. I suspect it would have done better with bigger engines (had the 337 been more successful, Cessna was ready to go with a larger engine version).
They are dirt simple to fly, but Cessna didn't get the wing angle of incidence right, so it is pitched up noticeably in cruise, which probably knocked 5 knots or so off the speed. The gear is pretty low drag as the airplane does pretty well on one engine, better than a lot of wing mounted twins of the same vintage. The good thing is that it goes straight ahead on engine failure. The bad thing is that it attracted a lot of pilots who were simply crummy pilots and who let their skill levels deteriorate so far that even the increased level of safety of center-line thrust couldn't help them.
People did try to take off on one engine. On a long runway it would do so, and enough made it that more tried it. On a short runway it wouldn't make it and the ones who survived claimed that the rear engine must have quit. Anyone who can't tell the difference in acceleration in a 336 on takeoff between one engine running and two engines running, IMHO, is too stupid to be flying any sort of airplane. The difference is huge. On two engines the airplane shoves you back in the seat, on one it makes a 150 on takeoff look like an F-16.
Rear engine cooling may or may not be an issue - instrumentation was an issue and may have given false alarms. Those who have put modern engine monitors in them say that the rear engine is adequately cooled, although that debate will never go away.
There is no room for baggage with six seats, none. Cargo pods were therefore popular and cut only about 3 knots off the speed. The 336 I flew always had at least one seat out of it so luggage could be carried, plus the useful load was such that it really wasn't a six-seat airplane. Check the weight and balance on the one you are considering.
The airplane is difficult to work on. It was not designed to be mechanic friendly and a lot of stuff was jammed into a small area (it got worse with the 337, T337 and P337). It has a rep for needing a lot of maintenance with aggressive preventive maintenance being wise and worthwhile.
Fuel burn can get as low as 9.5 per engine lean of peak, and so range isn't bad, but you are hanging in the sky.
Control harmony isn't all that great compared to later airplanes - the 337 improved on the 336 in a lot of ways.
The airplane will short field pretty well. I used to run a normally aspirated 337 out of a 1,700 foot runway (no obstructions) without any problem at all, although you had to approach on speed.
When I was instructing in 337s one technique I used was to have the pilot slow it down to approach speed, gear and flaps down, power back to about 15 inches and then call for a go around (at altitude). As he brought the throttles up, I'd pull one mixture control to idle cutoff (yes, I know, the FAA frowns on that sort of thing, but it was in the early '90s). The pilot would pitch up to climb attitude (a two-engine go around is no big deal, the airplane really performs) and the speed would just plain go away. The pilot generally looked surprised, trying to figure out what was going on as the noise level was identical with one at full power as it was with two and the airspeed indicator needled dropped so fast that sometimes the pilot thought it had broken. I usually didn't let them stall it, and announced that one engine had quit. The pilot would start the single-engine drill (you usually looked at the EGT gauge to see which engine had quit, rpm didn't show it clearly). Once he got through the drill, and I'd run the mixture forward and set zero thrust, he would clean up the flaps and start climbing out. I never let the pilot pull up the gear on those drills until we had 1,000 feet above our "ground" altitude as the gear doors generated LOTS of drag and we usually lost noticeable altitude during the 16 second or so retraction cycle.
Some years ago I looked at buying a 337 but backed out when I did the weight and balance and realized I couldn't carry enough in the cabin for what I needed at the time.
Frankly, I don't think I'd consider a 336 unless it were in absolutely excellent shape - and I haven't seen one that way in years. They are expensive to keep up and a lot get bought by people beguiled by the low purchase price and cannot afford the care and feeding once they get it.
Long answer, but if you buy it, go in with your eyes wide open and negotiate the price down a fair amount. You can count on attracting attention everywhere you go and you can count on people having strong opinions about the airplane; no one seems to be neutral.
Oh, yeah, it does perform better on the rear engine than on the front. That was the case for the first few years of the 337 as well, until they modified the front cowling and the single engine performance evened out. And, yes, people did shut down and feather the front engine in flight to get more range. I never quite had the nerve to do that one...
All the best,
Rick
