Jeep Strokers

Guess I should give an intro so here goes. I'm a ballistic engineer up in Maine and a major gearhead. This past summer I purchased a 1951 Dodge M37 from my towns VFD to begin a restomod for a daily driver. I have a V8 Jeep WJ that I have a love hate relationship with. It hates me, I love it. Mainly fighting the Jeep Flu with the damn 545RFE transmission not wanting to ground the starter relay.
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!

IMHO you should build a 4.6 stroker but carburate it with a clifford intake and 2bbl holley ...i so want to do this with my xj but im not going to because i wheel on very steep inclines

or even get creative and turbo a 4.6 i think that would pull a trailer...it would put you in the neighborhood of a stock 5.7 hemi power output

would it be remotely fuel efficient pulling a truck with a curb weight of 3 tons with me in it? I'm just concerned about putting that amoutn of load on the engine and tranny all the time.

with an ax-15 trans and a healthy built stroker or with any gasser with your tire gear and weight i wouldnt expect anything much better than 12mpg...how many miles a year are you planning to drive this? any major hills or high elevation?

I'm digg'n the look of that beasty your gonna wrench on.

tires are about 36" tall for those that aren't familiar with them and the diffs are 5.83's. Not looking to go over 60mpg max and if it cruises comfortable at 50 or so I will be a happy camper. Miles per year would be 6k minimum, all back roads, mildly hilly being in Maine. Guys that have swapped in 318's with the 4spd are claiming 15-18mpg if they don't lay into it and it isn't fully loaded which is reasonable. Eventually it will have 37" Hmmwv takeoffs with CUCV axles so the ratios will be down to 4.56 to help with cruising rpm's, but the engine still needs to be able to get it there without too much difficulty. GVW is around 13k which is the original onroad GVWR. 6k truck plus 3000lbs of payload, plus 4klbs trailer was how it came off of the assembly line. Offroad was knocked down to 11klbs, but I'm planning on this thing being able to haul at least a 7k lb braked trailer with an empty payload when the new axles and brakes are in.

The wrenching has already begun. The cab roof is off, tailgate is functional again, gauges are already redone, seats are pulled, and the front clip is coming off tomorrow to clean the engine and rip the rest of the wiring out. Big project, but lots of fun. If you check the FB album you can see the pictures, or the g741 site has the build thread which has been entertaining.

That is one cool ride. "ballistic engineer up in Maine" would that be BIW?

no but we work with them fairly regularly. I work for Tex Tech Industries

with just the truck you wouldn't have a problem with the stroker but the trailer weight...i don't think it would like pulling the trailer up a hill unless it was a boosted build

That's a neat rig but.... That's also a heavy truck with old school parasitic drivetrain, heavy tires/wheels, and brick like aero... I have doubts that guys are getting 15-18mpg with a swapped 318? Sounds a bit optimistic. They can barely get mid teens from a 5.2 as it is in a normal truck/suv... Unless you go diesel? I would bet that with any 4.6-5.7 sized gas motor that you install in this rig, you will always have your foot in the throttle while driving... killing your mpg. You need a motor with a TON of low rpm torque....The 4.6 is a torquey motor for it's displacement solely because of it's stroke length and the fact that it's mainly installed in lighter vehicles like XJ's. I'll bet a 4.6 will push that rig just fine but, if you are looking for good mpg? You need more torque so you can stay out of the throttle and keep the manifold vac up. I tow with my XJ/4.6 all the time and one of the rigs I pull in the summer is a 21' Malibu with a tandem trailer weighing in at over 4000lbs. It pulls up hills great! I can't say much for mpg tho unless it's really flat.. Then I can muster 12-15mpg if i get lucky and keep it under 60mph... For comparison, It averages 16-20mpg depending on the driving... Maybe a 4"+ stroker might be something to ponder? For mileage, you're gonna need more low end than the average Joe with an XJ and 31's...
Very cool truck regardless!

yea a 4inch ground crank with a .04 overbore gives you a 289 inch motor with well over 300ftlbs of tq and with the right cam it would be down low right where you need it...but still that trailer would be the tough one and i dont se a 318 doing any better than that unless its built specifically for low end tq...to bad you cant fit a 12v Cummins in it...that would be the way to go!

6TIME wrote: I have doubts that guys are getting 15-18mpg with a swapped 318? Sounds a bit optimistic. They can barely get mid teens from a 5.2 as it is in a normal truck/suv..

x2. If I behave on the highway I can get 19mpg out of my 98 ZJ w/ the 318 Magnum. Around town its in the 12-13 mpg range. I'm not impressed with the 318 in its stock form. Its only slightly faster than a ZJ with the 4.0L and drinks gas more. The only redeeming factor is that the exhaust sounds great.

My stoker in the XJ actually gets better MPG than the stock 318 does.

That 5900lbs is going to be a lot for the stroker to move. It would be much better than what you have now, but not ideal for the weight of the vehicle.

Nice ride man. Glad to see it's gonna stay Mopar.
Gas mileage in a M37 should be a non issue especially if your only putting around 6000 miles a yr on it. Your talking $16 a week difference from 10 to 15 mpgs. If your that worried about gas mileage buy a prius.
The only six banger that will make that thing get out of its own way is a Cummins. The little jeep motor stroked r not will be under constant load with very little power to spare, not to mention pulling a trailer up a grade.
If it were mine I would drop a 360 stroked out to 408 in there at the minumum. The dodge truck drive train and 360 magnum are easily sourced at any junk yard. If your set on keeping it computer controlled stay away from the OBDII systems OBDI would be the easiest route to go when swapping parts over to another vehicle.Every electronic part down to the window switches are run through the computer in OBDII.
A Dodge 440 in the M37 would be really bad ass.
Good luck with your build n post up some pics.

Turbo 4.6l. Tight quench, port the head. Try to build a more efficient motor...well more so than the stock 4.0 & slap a turbo on it. It'll move along just fine, and if you stay out of it I can see you get 14-15 cruise pending your "cruise rpm". Once your cruising it won't be hard to keep rolling, the stop and go will kill ya.