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Topic Review (Newest First)
10-10-2013 10:51 PM
brtben Best to you on this diesel project. A fellow at the Ocean City event had a diesel conversion ( 4 cyl. Cummins I was told), that got a lot of attention. I have high regard for you guys that can pull this off.
10-08-2013 06:20 PM

Read this thread twice now! It was out standing, like to see what you could have done with a space shuttle down here at NASA! LOL
10-08-2013 03:27 PM
miketrenshaw I read this entire post with fascination. What a great build!
10-08-2013 11:30 AM

You mentioned you replaced the rear axle with a Ford 8.8 with 3.73 gears. Did you replace the front axle gears with 3.73's?
10-07-2013 12:27 AM
sag just wondering were you got you new monark nozles?
05-30-2013 09:22 AM
NFGZ Awesome build man
05-29-2013 10:05 AM
snowbrd84 Spent around 2000 in parts total, but I sold the old engine and parts for a total of 1150. So only really cost me less than a grand...
05-28-2013 11:50 PM
Lamp So, all-in, what was your final cost on the swap?
05-20-2013 10:01 AM
snowbrd84 The girlfriend was in NY for the weekend, so I spent pretty much the entire weekend working on the Jeep.

I got the Dakota Digital tach adapter installed, very simple to install. I am a bit dissapointed in that I emailed Dakota Digital and they told me the tach adapter would work with the hall effect sensor. Well, it did not. The tach was bouncing all over the place with the hall effect, and no where near accurate. No big deal really, just means I had to run it off the W-terminal on my new alternator (stock alt for the OM617 does not have a W-terminal unless you add it yourself). I wanted to use the hell effect because that would mean no calibration necessary. Hooked up to the w-terminal, I have it reading about 600 RPM at idle, which is not correct, but I ordered a laser photo tach reader for $16 off Amazon, should get here today and then I can calibrate the tach. I am considering printing a new gauge face label for the tach though, since the stock gas tach has a much wider RPM range that is not needed with the OM617.

I also did some major re-wiring which I will add pics of tomorrow. Finished moving the battery from the engine compartment to the bestop rough rider storage box on the passenger rear wheel well, abandoned my idea of using a fuse box in the engine bay, and just re-did all of the wiring. It came out really nice I think, it is by far the cleanest wiring job I have EVER done. With all the space I gained by removing the battery tray, I ran the intake into that area.

Previously, I had the oil cooler mounted on the driver side front fender well in the engine compartment. I decided to attach it to the connecting support rod that goes from the firewall to the grill, right in between the brake booster and the grill. This gets it off the fender and lets it cool on all sides. It also looks a lot better.

Put in a lot of work on the interior wiring and installed some red indicator lights on the dash, one for the glow plugs and one for the EGT warning light. I also bought a 12v buzzer alarm, this will wire in with the EGT warning light. The digital EGT gauge has an adjustable warning level, you set what temp you want it to go off at, and it will trigger the light and buzzer. That way if you hit 1200 deg or so on the EGT, you will know it and not destroy the engine. I want to get an oil pressure switch and wire it up to the vacuum switch that shuts off the engine as well, that way if something goes and I lose oil pressure, it will cut the engine before it destroys itself.

Attachment 251473
05-16-2013 07:29 AM
Originally Posted by mattchatman View Post
Exciting! Let me know how that tech adapter works for you! I finally got my computer working so it's time to get some factory gauges working instead of GPS speedometers and old Mercedes gauges in the floorboard.
Ill let you know how it goes, if I get off work with daylight left, I am gonna try and get it installed today. I highly recommend getting a boost controller and egt gauge. runs much better at 14 psi.
05-16-2013 12:59 AM
mattchatman Exciting! Let me know how that tech adapter works for you! I finally got my computer working so it's time to get some factory gauges working instead of GPS speedometers and old Mercedes gauges in the floorboard.
05-15-2013 07:45 AM
snowbrd84 So I installed my Exhaust Gas Temp probe and gauge a few days ago. The turbo was putting out about 10psi boost before the wastegate would open. Flooring it on the highway at 10psi boost was sending my EGT up to about 1100 degrees. So I bought a manual boost controller off of eBay for 15 bucks. It mounts in the cab and has a knob to turn the boost up/down. It can only be turned down to the original setting, unless you were to go into the wastegate and turn it down there. However, I wanted to increase the boost for obvious reasons. So I cranked it up to 14psi. A lot more power and my EGTs are a lot lower under full acceleration...

I also just set f it and bought the Dakota Digital DSL-1 tach adapter. It gets here tomorrow. It has an option to either run the tach off of the w terminal on the alternator, or to run it off of the crank (hall effect) sensor. Running off of the Hall Effect sensor means no calibration which is nice. So I should have a working tach tomorrow....
05-14-2013 10:01 PM
Cashcrazy I have been wanting to do a diesel conversion for years. Great thread.
05-14-2013 10:43 AM
snowbrd84 Be nice to the donor when you pull the engine. i.e. dont destroy the front end, etc... And you should be able to get 400-500 from an auto recycler that will even pick the thing up from your house when you are done with it...
05-14-2013 08:13 AM
Nowiser Yeah I was planning on looking for a donor vehicle, there was one about 30 minutes south of me with 230k on the clock that i might go look at, he is asking 1500.

Great work! Hopefully Ill get pictures around of mine.
05-13-2013 04:25 PM
snowbrd84 Bought the engine off Ebay for 720 shipped. I would highly recommend just buying a running 300sd or 300d, 85 preferably. That way you know how it runs and you can use everything you need off the donor...
05-13-2013 11:23 AM
Nowiser Awesome swap! Looking to do this with mine as well, just bought the jeep and now working on collecting parts!

Was there a website you used to help you locate the engine?

05-06-2013 04:16 PM
armada505 have any videos of it running?
05-06-2013 07:49 AM
snowbrd84 I ordered some new Monark injector nozzles and they should come in the mail tomorrow. I also took an old 6 ton bottle jack I had laying around and built an injector pop tester. Only cost me about 20 bucks in parts, including a 5000 psi liquid filled gauge from harbor freight.

I was not happy with the wiring in the engine bay, it was a mess and with the amount of work I have put into this swap, I want to final product to at least look nice. So I went to the junk yard this weekend and found a really nice fuse/relay box out of some early 2000 car. Only cost me 20 bucks for the fuse box and a set of 5 injectors out of an old 300sd they had. Pretty good deal if you ask me.

I spent most of the day yesterday and did the following:

Moved the battery from the stock engine bay location to the passenger side Bestop Rough Rider storage box I have. Batter fit perfectly. I then removed the battery tray and installed the fuse/relay box on the firewall. I know have a ton more room there and this is where I am going to run the intake to as well. I then re-wired pretty much everything under the hood and covered all wires. Much much cleaner. With the fuse/relay box, I now have 6 full size relays, 4 mini-relays, and 8 high amp fuses 40-80 amps that I can run accessories off of. This is much much better than having a bunch of relays screwed to the firewall... Also, the fuse box has a + terminal on the side in case I ever need to hook up jumper cables. I will pose pics in a day or two once I am finished.
05-03-2013 10:33 PM
snowbrd84 in Maryland, any vehicle 20 years old or older can be tagged historic. No safety inspection and no emissions testing, ever...
05-03-2013 05:39 PM
tjtime Do you have required emissions inspections there?
05-02-2013 10:04 AM
snowbrd84 Here's a pic of the engine, still need to clean up some wiring. I also want to do a cowl intake to get cooler air to the turbo. This is my next project I think.

Attachment 244220

Here is a pic of the Jeep. Finally put on the JEEP letters and Sahara logo I bought after I painted the Jeep back in July, only took me ten months to get around to it...

Attachment 244219
05-02-2013 08:22 AM
snowbrd84 Acceleration is much better with the 3.73 gears versus 3.07 that I had. 4.10 would be even better in first gear but I think it would really suffer on the highway, causing the motor to rev to high at 65-75 mph...
05-02-2013 08:19 AM
snowbrd84 I then moved on and installed the slip yoke eliminator kit on the transfer case. I was able to do this with it in the Jeep. It wasn't fun but it wasn't the worst thing ever either... With the sye in, I measured for a driveshaft and ordered a CV drive shaft from Adams driveshaft. Length was 20-1/8" but yours will likely be different. Had them upgrade to solid U joints and it can with the explorer flange ready to bolt straight to the axle.

Holy shit I can't believe how smooth it is with the CV driveshaft, its like driving a new car, absolutely no driveline vibrations whatsoever. it's actually kind of weird driving it with it being so smooth, kind of like a calm before the storm, just wondering what's going to blow up next ....
05-02-2013 08:13 AM
snowbrd84 Alright so I pulled the d35. Installed new parking break shoes and pads on the explorer 8.8. Wire wheeled the entire 8.8, degreased it, and painted it black. Opened the diff, pulled the c clips and removed the axle shafts, everything looked great. I widened the locating holes on the 8.8 spring perches about a quarter inch and installed the axle without moving the spring perches. They overhang the springs less than a quarter inch and I see no issue with doing it this way. Used some old spring perch shims I had to rotate the pinion, got it pointing perfectly below the yoke on the tc. Ordered new spring plates on Ebay for 25 bucks shipped, had to pay 45 bucks to get U bolts made, went with 5/8" grade 10. In hindsight, make sure you get the explorer plates and u bolts when you buy your 8.8, will save you time and money... Made some new brake lines used the stock yj parking brake cables wrapped around the 8.8 lever. put in some good 90 140 Mobil synthetic gear oil since it has limited slip. Install went smoothly.
04-21-2013 11:04 PM
sag impressive mpg's that's one of the main reasons for me wanting to do this swap.
04-21-2013 12:24 PM
snowbrd84 20 gallon tank. About 280 miles and tank its about half full. Won't know until I fill up. But about 28 mpg.
04-20-2013 11:21 PM
sag any idea on what kind of fuel mileage your getting?
04-17-2013 10:43 AM
snowbrd84 The trigger for the glow plug relay hooks directly to the only solid yellow wire coming out of the bulkhead connector in the engine bay. I also have that wire running the vacuum switch that turns on/off the vacuum to the kill switch...

For the lower radiator hose, I bought a generic hose with one end that was a 90 deg angle. I connected the 90 end to the lower radiator port. I then used part of the upper radiator hose to connect to the lower radiator port on the engine. I mated the two hoses together with a 3" section of pvc pipe and some worm clamps. Works great and only cost 10 bucks for the generic hose. I did find some hoses that would have worked at the auto parts store, but they were like 40 bucks...
04-16-2013 05:35 PM
CumminsGift Great thread. Nice work!
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