Engine Swap Cat Diesel

[Muledeer2]

Has anyone out there done a diesel engine swap, my 1990 36 ft. Hawkins Motor Coach has a 3208 Cat V-8 and i was wondering if a if a 3126 cat or even an 8.3 cumminngs would bolt up to my 4 speed allison tranny, I have a side mounted radiator and there seems to be loads of room at the rear for a 6 cylinder engine, I do know that there were some Hawkins that had 6 cylinder Diesels, I was thinking of something in the 300-325 hp range. My coach still has pretty low mileage 38,000, but I was trying to deciede what to do when it does eventually have an engine problem.

[BFlinn181]

Before going too far, check the specifications of your transmission. I think the 300-325 hp range you're looking for would burn out a 4 speed Allison. The torque would be way too much. An engine swap would probably be more costly than the RV unless you've got a free engine and all the shop tools to do the swap. A Cat 3126 weighs about 1300 lbs, a Cummins 8.3 about the same or a bit more. According to the horsepower of your engine, a 210hp engine weighs 1,592 lbs., the 375hp engine weighs 1,702 lbs., and the 435hp engine weighs 1,982 lbs.

[TBS-POPS]

At only 38000 miles you've got a long time to think about it cause that 3208 will go to 500k before it even thinks about having problems. A full engine and trans swap would be more in line for better performance and reliability. The boys at a cat truck shop can get you better performance and power out of the old 3208 if that's what your after. The 3208 is a great engine.

[Muledeer2]

Thanks for the Reply the 3208 weighs in at right around 1,800 pounds pretty close to a 3126 or the cummings 8.3, I have no problems right now, but was thinking that in the future if i came across another engine i might buy it, whether it's another 3208 or something else, i know about the tranny not taking the additional torgue, but it really won't add anymore torque than i already have, for more torque rule to apply wouldn't the rig have to either weigh more or be pushed faster and harder to increase torque, none of which i want to do, I was more concerned with part interchange and availability, and the 3126 or 8.3 can be detuned to, I don't believe I am saying this but to make less horsepower and torque. LOL WOW someone who wants less power who would of thought of that, We love our current coach and it construction too much to try and change for something else, it's pretty much old school, Gillig chassis, air brakes and air ride suspension all real wood interior with corrian counter and all the whistle and bells except no slides which i love for several reasons, we dry camp most of the time and like the 60 gal propane, 65 grey and black along with 100 water and 100 fuel tanks. Thanks again for the reply Muledeer2

[Muledeer2]

Thank you for the Reply, I have already taken steps to increase HP in the 3208 and it does quite well, my only concern is parts availabilty for 3208's is drying up fast, and if you are 2,000 miles from your home base and have problems finding repair parts and someone who is good with that old engine can be an issue, we love our coach the way it is and have never thought of getting bigger, just more reliable, Like i said the engine compartment has plenty of room for a 6 cylinder and i really don't need the extra HP, was just thinking that if I came across another engine from a wrecked coach I might pick it up for a later install, better yet if i could find an engine and 6 speed for a good price. You could be right on mileage we had an old ford 34 foot bobtail delivery truck at work that made deliveries out to about 200 miles and back everyday and it had 640,000 miles on it when it was retired from service and it usually weighed about 29,000# loaded or course it had a 5 speed with a split rearend for 10 speeds. It might be that I am not comfortable with the coach yet as far as being reliable, we have had if for about a year with no problems so far. Thanks Again muledeer2

[Borderbuster]

we have a Cummins 8.3 and world 6 speed tranny in our 93 HMC. Our rig has a "mechanical" engine and a computer transmission. I would hazard a guess that it would take several mods to fit it into a Gillig chassis that was made for a Cat 3208: mounts, electrical, exhaust, plumbing, etc.
If you need parts and pieces, look to the marine vendors, Cat 3208's were put in about a zillion boats.
Even though I prefer the Cummins over the Cat, I would stick with the Cat in your situation. That being said, I like the Hawkins so much that I would put another engine in it when I wear this one out rather than change coaches. They really are a gem in the motorhome category.

[BFlinn181]

I looked into increasing power of my 5.9 Cummins which is easy and inexpensive to do. Step one was look at the specs on my Allison transmission. While very robust, it is close to max on hp and torque as is, so I gave up on modifying engine. Torque and horsepower can exceed transmission limits just by pulling onto an interstate or going up a hill. I decided it wasn't worth it.