Anyway
Here is a link to the build thread that I started on a dedicated M37 website.
http://www.g741.org/PHPBB/viewtopic.php ... 258#p45258
and here is the link to the public Facebook album with all of the pictures
https://www.facebook.com/media/set/?set ... 581e3dc797
I have known from day 1 that he would need a new engine. Unlike the flathead 6's from Chevy and Ford, the Mopar L6 does not have great potential for power and has very limited aftermarket support. As it sits, it has around 90bhp and 190ish ftlbs. The torque is enough to get it moving, but due to a very restrictive RPM band *it revs like a diesel* and the lack of hp means it crawls at 25-30mph up any sort of incline. I initially was hell bent on getting a diesel put in this thing but am now very much on the fence leaning towards a gasser. Hopefully you guys can push me in one direction or the other and I apologize for the lengthy post.
The Dodge M37 for those that don't know is very similar to the Jeep M715in that it is a one ton ish truck but is much smaller than the one tons of today. Unfortunately, unlike the M715 it doesn't have Dana axles. The truck weighs in at a whopping 5900lbs as it sits with 5.83 diffs and 36" tires. Due to the immense weight of this thing combined with the steep gearing I was thinking about swapping in a diesel which with a 4BTA many people with these are reporting 22mpg combined which is quite impressive for a 3 ton truck. I have issues with I4 Cummins engines because they rattle like hell. There is a guy locally that will sell me an Isuzu 4bd2t with auto tranny for $1500 out of a running NPR truck. The Isuzu runs a lot smoother than the cummins but it still clicks and clacks at idle and has a decent amount of shaking going on. This is the main reason that I keep leaning towards gas. The WJ is going to last for another 6-7 years I hope and while it only gets about 15mpg now that we're on E15 and on the winter blends, it's a comfortable and valuable DD. The 4.7L V8 is a brilliant engine as is the new 5.7L Hemi and would work well in a truck like this, but finding standalone computers for them is all but impossible, especially when you want to put a stick shift behind them. I found a guy locally that has a 4.0L with 120k out of a 1998 Cherokee and also has the 4.2l cam and rods and only wants $300. I don't know if that is fully dressed or not, but if it is, I think that would be a great opportunity to keep an I6 Mopar engine in this truck.
With these strokers I have seen some that can still run 87octane be fine which would be preferable although it would have to run on maximum 91octane which is all I can find up here. I emailed the guy mentioned above asking if it comes with the stock wiring harness etc, but even if it does, can I easily rig up an OBDII system without any cat converters, ABS, etc? I'm not afraid of doing the wiring involved to get the computers to work, I see the advantages of an EFI system, especially since I live in Maine where it gets quite cold up here and having to deal with carburetors in the cold is not fun, and I imagine that a Megasuirt system could be adapted and I'll dig through the forums to find out, but is adapting an EFI system like this worth it or possible when I won't be using any Jeep gauges and obviously won't have ABS or a cat? Are any of these systems self learning with knock sensors to detect different octane levels so if E85 decides to come into Maine I would be able to use it?
I guess the main question is would a 4.0l motor or a mildly stroked version of said motor be capable of pulling a 3 ton truck with potentially another 2-3 tons of trailer behind it on some occasions around and be reliable? What manual transmissions are easily adapted behind these that can handle the load of this thing? Most of the guys that build these trucks with the cummins but a nv4500, Ford ZF5, or the Spicer 3053A transmissions behind them, but they are quite expensive and I think are massively overkill since they were designed for some big diesel engines.
Thanks!
