Posted by Charlie on October 26, 1998 at 20:33:05:
In Reply to: Diesel in WM300 posted by Jeff on October 25, 1998 at 18:49:50:
I am putting a Hercules DT3.7 (just like MARS' engine) in a 48 B1PW. It is NOT a bolt-in, but there's room. I fabricated a "saddle" between the two rear frame pads and the Chevy bellhousing I'm using sits on inverted "U" shaped rubber pads going over the closed part of the 3" channel I used. In front, MARS' front motor mounts are about 1.5" too wide. So I'm welding a 1.25" plate of steel to each end of the front crossmember which is drilled and tapped for the 5/8" bolt I'm using for the front mounts. If you used a PW bellhousing bolted to the 3.5" thick adapter for the M37 conversion the rear would be a bolt-in, of course. But I wanted additional length for my NP540 5spd. The Hercules is a good choice for compact size, weight, and power-to-weight ratio. A cummins 4BT would be great also, but with a 2600 rpm governed speed a 5 speed is essential; watch that length! The popular NV4500 5spd has a long tailhousing. the Clark 280VOs and NP540s are hard to find in overdrive configuration.
With the WM300 I believe there's 2" extra at the front, making a small 6 a possibility. I sincerely doubt a Cummins 6BT would fit (and it would be overkill), but a Landcruiser 2H (3.98L, 102HP@3600, 178ft-lb@1800), or 12HT (135@3500, 235@1800-2000) or 1HZ (OHC 4.0L, 129HP@4000, 220ft-lb@2000) or 1HD-T(165HP@4000, 275ft-lb@2000) might fit. Call up Marv Specter at Specter Off-Road in Northridge, Calif (818-882-1238), tell him I told you to call, and ask him to measure the distance from the front of the fan to the back of the upper part of the block. Add at least 1.5" at each end for clearance and compare with the radiator to firewall distance in the WM300. It would be a fabulous conversion. (Expensive too, if you buy a "test" motor from Marv- a motor with 100 miles on it or so. The test sixes run $5-7K new). I believe the Landcruiser diesel sixes are interchangeable with the gas six regarding transmission conversions. So you could keep 5.83s and run a NV4500 with 0.74 5th gear, giving a 4.32:1 final drive, or 2500 rpm@60 with 9.00R16s, or 2340 with 11.00R16s. There are LOTS of good 4 cyl engines with direct injection, rpms in the 2600-3000 range, and putting out 180-270 ft-lb of torque, depending on turboed or not. An intercooler would be hard to plumb because of the radiator setup on the PW. Of all the choices for the 4s, I'd look hardest at Hercules, Cummins and Isuzu (the 3.9L version). A 5 speed is very advisable, depending on tire size, axle gearing and intended use. Don't set it up so that you are constantly driving within 2-300 rpm of governed speed. It will be very noisy and burn more fuel than needed. Also, it's frustrating to have to drive 55 if you have the power to cruise at 65. And now there's no excuse for not having disk brakes in the front with a repower.
Charlie