3208 CAT safe rpm

[jmark470]

I just bought a 89 motorhome 3208 turbo 250 hp Allison 4-speed. At 60 mph 2200 rpm, 65 2400 revs. A friend told me these engines were light duty applications, stop and go local use, not designed for coast to coast use at high rpm. Going on a 4,000 mile trip, what rpm can this engine sustain while keeping the rods attached to the crank?

[nevrenufhp]

You can actually take it to 3200 and still stay intact, not that it should need to. It can take 2800 continuously. Your mileage is what's going to suffer more than the engine's life span.

[jmark470]

The sticker on tach says, "Never Exceed 2800 rpm." All the info I've read about 3208 indicates that it is a problem engine. It has 33,000 miles, I adjusted valves to spec, they were a litle loose, coolant flush, all filters etc. I,ve driven it about 1,000 miles carefully @ 60mph, but 2,000 miles on interstate I,m too impatient to stay at that speed regardless of the mileage consequences. So to be clear, can this engine can set at 2500 rpm all day?

[fddriver2]

Put taller gears in the axle......... Kind of pricey, but it is an option.......

[sdan27]

i wouldn't think 2500 rpm would be a problem at all. we have an old tractor with a 3208 in it and we run it at 2800 with no problems.

[jmark470]

Thanks for the responses

[TEXASBEN]

Have a 1991 Hawkins 33 motorhome, runs at 1900 rpm at 65 mph wt is 25,000 lbs. Pulling a Checy Tracker(3700 lbs) and gets about 9 mpg. At 70 tach reads about 2050 rpm. have an Allison and runs 22.5 tires, hope this helps

Ben D (TexasBen)
north central Texas area