they seem kinda heavy too, and that would limit my ability to flat tow behind them.
As far as diesel pushers go, are there any motors to avoid?
CAT is no longer in the OTR engine manufacturing game but their parts availability are still great. Cummins and Detroit are about the same as parts accessability, pretty good overall.
Personally, I like a sleeved diesel engine vs. a non-sleeved engine but that is just me. If a rebuild ever is needed it can be done in-frame.
I would suggest sticking to the parameters I listed earlier if you are looking for something that performs descent, 1 HP per 100 pounds of weight and/or 45 pounds of weight for every foot-pound of torque. The bigger the coaches go the heavier they get and engine sizes get larger, but power to weight ratios are fairly consistant in "most" cases. I say "most" because like everything else, there are exceptions. There are some that are a bit undersized in my opinion. One that sticks in my mind is a buddies Discovery that only has a 275 hp Cummins B engine. Moves out OK, but really struggles on the grades, especially when he is towing his trailer.
Our old 91 Beaver was borderline, it weighed right @ 29k pounds with a 300HP CAT 3208. It did fair but it was only coupled with a four-speed Allison tranmission, had it had the MD3060 six-speed I am sure it would have done better as it would have had wider spaced gearing. That said, if you end up going older, I would recommend avoiding the old two-stroke Detroits (6V and 8V engines) as they are not environmentally friendly and hard if not next to impossible to pass emissions if needed. My old 3208 CAT was borderline as well. I got it burning clean but in CA they don't even want anything to do with the old V-8 CAT engines. Also, the 3208 CAT, while a pretty good engine, is not a sleeved and not as high miler as many newer diesels so when a rebuild is needed the entire engine will need to be removed to bore and machine. Many of the coaches that these V-8 CAT's come in are not the easiest to remove the engines in. I helped my uncle do his in his 1988 Beaver Marquis and the we had to cut the rear crossmember out and make a bolt-in replacement as the coach was obviously built around the frame/engine/trans. My counsins 1987 Vogue was the same way with the 3208 CAT engine. Luckily mine never gave me any problems and when I sold it she had 129k miles on her which from my understanding is pretty good for that engine so I wasn't expecting too awfully many more. Many of the newer diesel engines they are just getting broke in at that mileage. So would I avoid the older CAT V-8, depends on the deal you were able to get whether or not you could justify putting money into it if it ever gave out on you. I would definetly avoid the older 2-stroke Detroits though.
Mike.