Yet another 6bt swap...

[conehead]

I think your radiator will be more than enough. I just used the J-20 factory radiator and it work fine. I didn't even have any fans on it for the first couple of years while I was trying to find a electric fan setup for it. The only time the engine would run warn was when the truck wasn't moving on a hot day and even then it took a couple of minutes.

[jaber]

Here's a link to my build thread. The Cummins swap starts about half way down the page. I grafted the Dodge core support into the jeep core support so I could use the dodge factory radiator, inner cooler, and a.c. condenser...

http://www.ifsja.org/forums/vb/showthread.php?t=110126&page=6

[jaber]

[BA_051]

Wow awesome build thread for sure Jabber. Shortened the dodge frame and put the Jeep body on it. I’ll be using the Jeep frame and will build a frame crossmember with the engine mounts just like the dodges.

I was looking at the factory dodge rad and it’s core is 36x19 whereas mine is 22.5x19. That’s a lot of extra cooling capability.

It will be a month or so before I resume working on it. Need a storage unit and clutch kit... thinking about the street dual disk, but Valair recommended the single HD 13”... $300 difference...

[BA_051]

Well it has been a month and a half and I finally had enough saved up for a Valair clutch kit and input shaft... Figured i needed a new input shaft so I went ahead with the 1.375" upgrade.... Do it right the first time... I will have that delivered tomorrow, Friday Jul 13th... The guys at valair recommended the single HD clutch over the dual disk... Its only about 400hp and I dont tow a lot so the dual really isnt needed anyway.



Today was very productive... I hoisted out that 6.5 in about 4-5 hours.


There are 2 issues I see thus far... One being my NV4500 is from a 1995, it has the small bearing retainer so I will have to have my new one machined out to fit (about 15 mins on a lathe), and the 2nd issue is the NV4500/NP205 will have to be moved back about 8" so shortened rear/longer front drive shafts are in order we well...

[BA_051]

Well the clutch came in and I bolted it up. Everything went together without issues, as expected. This clutch is huge compared to the 6.5TD, as is the 1 3/8" input shaft...
Here is the clutch kit.


Here is the 1.375" input, bearings, and retainer.




And Comparing the GM 1.125" to the CTD 1.375" input.



The issue with the retainer was really simple. $100 at a local machine shop in Everett turned down the transmission pilot diameter on the retainer to the same as the old one and used a mill to elongate the holes as well. Really simple job. I didnt get pics since its a super simple job, but I was worried about end play and having to tear the NV4500 apart to re-shim the shafts. It turned out, since I used a full cummins rebuild and pressed the cummins bearing race into the GM retainer, when I swapped the retainer, the new race was only 0.002" deeper in the transmission. That tightened up the end play a little, but I built it at 0.004" end play, 0.002"-0.010" is the spec in the TSM. If i Had used the GM bearing, I would have had to re-shim the mainshaft and counter shafts.


And the trans reassembled and the AA bell and parts ready to receive the motor, but it is still in the same location when it had the 6.5TD, I havent moved it yet.



And the CTD being hoisted into position... Man I HATE lifting a 1400lb motor that high... the top of the bumper is about 42" off the floor.....



I spent all day Thursday (7-26) getting the motor bolted up to the NV4500 and had to get really creative on how to allow the CTD/NV/205 to move back while still being supported... But by the afternoon on Friday the 27th, the new crossmember was made and it was bolted up to the frame and the trans/tcase were supported by the frame. Hopefully, I will have the motor mounts done next week...

[BA_051]

Well I stopped by the storage on my way home from work and snapped a few pics of the cross member... Dont mind the dirt and oil, it was from that leaky 6.5TD.... It will get cleaned up



From the front...




From the back... There is about 1/4 to 3/8" gap between the top of the front output and the body, just enough...


And from the side...




As you can see, no part of the bellhousing, transmission, or transfercase are below the frame... Those are 9/16 fine thread grade 8 bolts bolted through the frame and cossmember...

[SJTD]

With only 3/8" clearance are you sure it isn't going to hit when you give it some willy on a steep hill?

[BA_051]

Only time will tell. The motor isnt in its final position quite yet. I havent had much time to get the motor mounts finished. Between kids appointments and having to get an oxy/acetylene setup it has been delayed week after week.
On a good note however, I picked up and will be using hydraulic motor mounts so it should keep the motor vibrations to a minimum. Just need to get welding!

I had clearance issues with the FSO solenoid and the brake master cylinder so I removed it from its factory position and need to make a new bracket for it...
I was able to fabricate a bracket for the injection pump to throttle cable. I just used the same cable i had used for the 6.5TD. It was strait forward and works very well.



I also dropped off a fan hub at the machine shop to be modified... I am using the industrial fan hub from a 4bt because i needed the fan to be centered and moved ~3" higher. This fan hub does just that but will not bolt up the factory fan clutch and pulley...


First, 3/16" will be taken off the mount face to move the entire hub closer to the block... This is because the bearings sit about 1/16" higher than the original hub. That will cause the bearings to sit 1/8" closer to the block now.
Second, 1/8" will be taken off the fan side for clearance. The snap ring sits 3/16" down in the bore with the bearings behind it so that will be reduced to 1/16" leaving 1/8" total from the face to the bearing. This is for clearance purposes...

Third, the factory hub will be machined down from 32mm to 30mm to press into the industrial bearings. Also, as you can see in the above pic, the shoulder on the industrial hub is much longer. Once the factory hub in machined, it will have a second shoulder 1/8" below the first one increasing the total shoulder height from 1/8" to 1/4"... Remember the 1/8" I had taken off the hub bracket face for clearance? Now this will leave 1/8" between the hub and the hub bracket once they are pressed back together...

[Mikel]

Very nice

[BA_051]

And after a few days, I got the fan hub parts back and reassembled them...


The hub brackets sit almost exactly the same height! You can see the bearings sit 1/8" down from the front now on the industrial bracket (Right) face vs flush on the Dodge bracket (left, no bearing).







And the fully assembled fan hub.



I will be over at storage later today to get it bolted on and hopefully get the passenger side motor mount finished. Then tomorrow, The drivers side mount... After that, I will be changing my radiator. The one I have now should be sufficient (its 27.5" width overall, 22.5"x19" core with 1" pipes), but its all dissembled now so it would be easy to widen the core support and drop in a bigger radiator. I havent decided yet on the size really, there are 2 options. A universal Griffin MegaCool that has 1.25" core pipes and is 31"x19" overall with a 26"x19" core or try and squeeze in the stock dodge cummins radiator; but that is 44" wide total with a 36" wide core....


Once the motor is bolted in on its mounts and the front core support is ready to go back in, thats when I will decide...

[BA_051]

Well much has happened since my last post...I finished the motor mounts (very strait forward using 3/8" steel), got the fuel lines redone (moved from passenger side to drivers side on the frame) and hooked up and I modified the inner fenders... Also in the process of rewiring the front under hood harness. I picked up a fuse box from a 1992 XJ that I will wire up and use the relays to power the headlamps, starter, ect... I twill really tidy everything up.


Here are some pics of the motor sitting on its mounts and the fenders bolted (loosely) back into place... They arent completely finished, I will trim and drill the top that bolts to the core support as soon as I get it back in and also widened...


The bottom of the tray is 6" down giving my 14" from the tray to the lowest portion of the hood. I can fit 4, 94 size batteries under the hood now and still have room...




The 18ga sheet metal cut and formed to be welded into the inner fender.








Next week, Hopefully I will be able to get the core support mounted and my new radiator installed. I know the factory size one will work for a stock or mild cummins, but this one has 50hp injectors, 17 degrees advance on the timing, KDP fixed, and will be running a modified HE351 as seen in the pics. I found a 36"x18.5" rad that should fit very well...

[BA_051]

I had some time this morning to work on it and I installed 1" body lift on the cab to gain some clearance between the transfercase and the body and to also increase the distance between the top of the frame and the hood to fit the new radiator a little better.


Here is a mock up of the radiator and core support. I cut off the body mounts of the core support and have it just resting there mostly in position to check the fit of the radiator.


I didnt remove the mounts on the frame yet so the radiator will drop down about another 1-1.5 inches.



Also, in the second pic, there is about 1/2" between the fan and the radiator but it is not in its final position. It will go another 1-1.25" forward leaving 1.5-1.75" between the fan and radiator. It will be mounted in the same location as the factory radiator as soon as I get the core support welded back together.

[bluehwy]

Loving your build! Thanks!

[BA_051]

Thanks Bluehwy. It?s a lot of work swapping this beast...

Today I spent much of my day fabricating the new core support body mounts and welding them up. As of this moment, the core support and valence are all bolted back up. I had to adjust the hood latches a little bit no biggie.

I have the radiator mocked up and it seems I don?t need the body lift at all. I can keep it exactly as is and just mount the radiator 2? above the frame, or remove the body lift, mount the radiator an inch lower, and make a better crossmember and lower the transfer case about an inch. I don?t know what I?m going to do really...