Posted by Charlie on September 06, 1998 at 00:44:28:
In Reply to: Charlie Aarons-tell me about diesel repower posted by Bryan on September 05, 1998 at 20:13:58:
First of all, he can call me at 9-10AM on weekends or after 7PM weekdays Alaska time at 907-349-8673. I'm off work next week so he can call me in the AM weekdays. Make sure he knows about time zones, I don't like phone calls at 5AM
I am about 1-2 weeks away from installing the motor. In the front I used M37/Hercules motor mounts. They don't exactly match the holes. The holes will be a bit less than 1" outboard and 1" back from the original holes. That's close to the edge of that closed in cross member, so I'm going to weld a pice of 1" steel plate to the crossmember and drill and tap it for the big motor mount bolt. All the rubber insulators will be above the cross member so there's no need to get inside it. For the rear I fabricated a "saddle" out of 3" 6.1 lb/inch channel. It bolts to the rear frame pads with a 5/8" grade 9 bolt on each side. The insulators are riding on and inside the channel. I did not use the M37 flywheel and adaptor piece, it's too long. Instead I got a Hercules to Chevy (they also make Ford) 1+" thick adaptor plate from Hercules. Bolted to that is a older cast iron Chevy truck bellhousing with flats machined towards the rear at a 30 degree angle from horizontal (that's the reason for this saddle I made out of 6 pices of channel). I got a 12" clutch at the local clutch store, and attached that to the flywheel I also got from Hercules. One could get a new Chevy truck bellhousing and use the NV4500 transmission, 2WD version, and maybe have enough room to not move the transfer case. I'm using a NP540 I've had in a Perkins powered FJ45 Landcruiser since 1979. The clutch is hydraulic; I'm using a Landcruiser master and slave cylinder (I just happen to have a lot of these parts laying around in the garage!). I also borrowed the whole pedal assembly from the FJ45 so I have overhung pedals, dual master cylinder with vacuum boost (the motor came with a vacuum pump if I can figure how to mount it). I may not even need to shorten the intermediate shaft but the transmission end needs to be changed to a Spicer 1350 pattern to match the yoke.
I had a set of springs made up at Alaska Spring. They are 6 leaves of 0.323", replacing 11 leaves of 0.260". I estimate they'll be 20% softer. They have 2" more arch than stock; they should ride with 3-3.5" between the frame and the axle bump pads (which I also stole from the Landcruiser). I had a certified welding shop cut and dog-leg the steering arm off the knuckle up 3" because the drag link is so short. I replaced the drag link with an item I bought at the surplus dealer from an F600 Ford or something like that. It's a hydraulic "brain" with 4 ports: 2 to and from the pump and 2 to and from a ram which has yet to be mounted to the axle and tie rod.
I had a good machinist copy Tim Peterson's disk brake setup that works so well on the front of my M37.
The drivetrain place is having Chelsea build a reversible PTO out of parts for the quite obsolete NP540. I'm trading that for a take off rear axle I don't need from my F350.
I will probably install 4.89s, they are on order, but I want to try it with 5.83s first. When I change the gears I'll install Lockright(s), and front disk brakes.
In summary, the motor installation while not particularly difficult is a custom job. If MARS would build new front motor mounts, then a setup in the rear similar or identical to the M37 would make it a "bolt-in". However, it's nice to have the extra 3" because obviously the 9" long crash box is asking to be replaced in a conversion of this sort, either by a more modern 4 spd (even a M37 NP420 synchro in 3rd and 4th would be OK) or better yet a 5spd. In particular the NV 4500 hold interesting possibilities. It has a pretty tall 0.73 5th gear. 0.73 X 5.83 = 4.26. With 11.00R16s that's 2300 rpm at 60. Even with 9.00R16s it's 2450 at 60. If you figure $626 for 4.89s, plus freight, plus installation, that's a savings of $1200! Those 5spds cost about $18-1900 in rebuilt condition. I believe if someone is going to the expense and trouble of a diesel conversion, one should do a "balanced" job and upgrade the brakes and the transmission, to get the reasonable "keep up with traffic" speeds that the vehicle will now be capable of, and to be able to safely stop it. Also, the bias ply NDs must be replaced by preferably a radial, we all know there are several available that do as good or better than the NDs in mud and way better on everything else. And Michelins are still military spec; not from the 40s-60s, but from the present.
One last thing. If MARS doesn't make the necessary parts to make a bolt-in, then I can say the Hercules is a lightweight compact package that puts out good power. But other nice diesels that would be appropriate would be Cummins 4BT, Isuzu 3.9, venerable Perkins 4.236T or 1004T Phaser, AND 6.2/6.5 GM V8 (tight fit, I wouldn't even think about a turbo). The 6.2/6.5 has more rpm flexibility than the 4s, but the 4s are more "industrial". Jim Bescheinen in Nebraska squeezed a 5.7 Olds diesel into a Power Wagon. I drove it, it seemed nice. He has a TH350 3 psd auto and 4.30 3rd members from late 40s 2WD Dodges (I know, I didn't know about them, but I guess if you can find them - obviously almost all of them are dead and buried and the live ones probably don't want to be donors for Power Wagons and M37s) they came in 3.91, 4.10 and 4.30.