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'81 Ram Cummins conversion begins!

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  #1  
Old 02-05-2010, 09:35 PM
racer9 racer9 is offline
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Default '81 Ram Cummins conversion begins!

Got started on the project this week. Pulled the slant6 and trans out.
Going with a Cummins 4cyl turbodiesel, and TH400 trans.
Trial fit of the Cummins shows it almost sitting right on the /6 motor mounts. The bolts line up and start in the holes, but the pan hits the crossmember and steering draglink. It looks like the mounts can be moved back a couple inches, I'll try that and see what happens. I may need to raise the mounts up a couple inches. The other option is getting the proper mounts from Dodge, but what fun is that?
Amazingly the rubber motor mounts appear to be the same on both motors.
I'll get a couple pics when I test fit the motor again.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #2  
Old 02-15-2010, 10:55 AM
76powerwagon 76powerwagon is offline
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does the th400 tranny bolt right up to the cummins? and is yours just going to be 2wd?
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  #3  
Old 02-16-2010, 10:58 PM
racer9 racer9 is offline
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I got mine with the TH400. There are flywheel housing adapters to allow the Cummins to bolt to almost anything. What are you looking for? Yeah, mines 2wd.

Heres some pics:
Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #4  
Old 02-17-2010, 05:46 PM
76powerwagon 76powerwagon is offline
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some day I would really like to convert my 76 power wagon to a cummins but I really want the 6 cylinder for better pulling, Im probably just going to buy a 1st gen doner truck that has a bad frame or something like that. I really like your project tho keep us posted as you go.
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  #5  
Old 02-17-2010, 07:25 PM
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Dodge_Ram_3500 Dodge_Ram_3500 is offline
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Nice man! Good luck with her, should be interesting to see the final result.
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  #6  
Old 02-17-2010, 10:59 PM
racer9 racer9 is offline
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Quote:
Originally Posted by 76powerwagon View Post
some day I would really like to convert my 76 power wagon to a cummins but I really want the 6 cylinder for better pulling, Im probably just going to buy a 1st gen doner truck that has a bad frame or something like that. I really like your project tho keep us posted as you go.
What are you planning to pull? These 4cyls are in a lot of 1 ton step vans, where mine came from. Either one is a great motor. The 4 will get better mpg's.

So, after another test fit, I need to modify the motor mounts and crossmember a bit. In some step vans the motor is slanted a little to allow clearance for the drivers compartment. I have one of those. I need to raise the right side of the motor about an inch, and the left side about 2", to level the trans. I want to use the rubber motor mounts, so I'm using 2 1/2" plates sandwiched around the right mount to lift that side an inch, and using a section of 2"x2" box tubing to raise the left side. The crossmember will be slit lengthwise on each side, and an inch or so cut from the back side, then drawn down, welded back together, and some filler panels added. This is due to needing a little more clearance for the oil pan, and to allow easier install of the motor.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #7  
Old 07-04-2013, 03:30 PM
racer9 racer9 is offline
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Time sure has flown. I didn't realize that I hadn't updated my project, so here it is.
I ended up rebuilding the motor mounts, moving them further back to better support the weight of the Cummins.
The motor had a 8* tilt in the step van, it is now 4*, split between the motor and trans. I had to get a 6bta exhaust manifold, cut 1 cylinder off each end, and cap it, to get the turbo into a place where it would work.
I had to build a crossmember for the trans.
I eliminated the brake booster, because I had no vacuum source, but that resulted in a hard brake pedal with little stopping power. I went to a smaller bore master cylinder and as soon as I can get a little help to bleed the brakes I'll know if that worked.
Hopefully it will and it will get inspected and driven daily.
It is now moving under it's own power.
Here's the build pics, start to now.
http://i114.photobucket.com/albums/n...s/P1020519.jpg
http://i114.photobucket.com/albums/n...s/P1020520.jpg
http://i114.photobucket.com/albums/n...s/P1020521.jpg
http://i114.photobucket.com/albums/n...s/P1020654.jpg
http://i114.photobucket.com/albums/n...mins/001-2.jpg
http://i114.photobucket.com/albums/n...mins/003-2.jpg
http://i114.photobucket.com/albums/n...mins/004-2.jpg
http://i114.photobucket.com/albums/n...mins/005-1.jpg
http://i114.photobucket.com/albums/n...mins/001-3.jpg
http://i114.photobucket.com/albums/n...mins/002-3.jpg
http://i114.photobucket.com/albums/n...s/P1020763.jpg
http://i114.photobucket.com/albums/n...s/P1020759.jpg
http://i114.photobucket.com/albums/n...ps546bb4c6.jpg
http://i114.photobucket.com/albums/n...pse08f1550.jpg
http://i114.photobucket.com/albums/n...ps5a21d608.jpg
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #8  
Old 07-05-2013, 09:18 AM
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Nice. Looks like a clean conversion. Is the truck staying orange, or going plum crazy?

By the way, what gear ratio is in the truck that you decided to keep the 3-speed auto?
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  #9  
Old 07-05-2013, 09:53 AM
racer9 racer9 is offline
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Quote:
Originally Posted by wontacceptthis View Post
Nice. Looks like a clean conversion. Is the truck staying orange, or going plum crazy?

By the way, what gear ratio is in the truck that you decided to keep the 3-speed auto?
It will get painted "Plum crazy" later, right now I just want to drive it!
Went with a 2:55 rear ratio. That should put me around 1700 at 60mph, right in the Cummins power band.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #10  
Old 07-05-2013, 01:03 PM
dodge dude94 dodge dude94 is offline
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2.55 or 3.55? I've never heard of a 2.55 for the 9.25 rear end...

Looks side either way.
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  #11  
Old 07-05-2013, 03:19 PM
racer9 racer9 is offline
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2:55, Ford 9", out of a Cougar.
The oem light duty 8.75 rear would never have held the diesel torque.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #12  
Old 07-05-2013, 03:35 PM
dodge dude94 dodge dude94 is offline
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Didn't know you had a 8.75. Most useless rear end in a pickup ever. What kind of get up and go does it have?
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  #13  
Old 07-05-2013, 03:52 PM
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crazzywolfie crazzywolfie is offline
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i wouldn't mind knowing what type of gas mileage it gets?
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Old 07-05-2013, 05:18 PM
racer9 racer9 is offline
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Haven't driven it highway yet. Finishing up little things, like the brakes. Trying to get help to bleed the brakes, hopefully this weekend. If brakes are OK, then state inspection, and hit the road!
BTW, not "gas" mileage, fuel mileage!
I'm shooting for 30mpg.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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  #15  
Old 07-05-2013, 05:24 PM
dodge dude94 dodge dude94 is offline
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Are you going to put a 6BT setup on it as far as brakes? I would think that with the rolling mass that the truck has you'd want some assist...
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Old 07-05-2013, 05:27 PM
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i don't think he is since i am pretty sure the 6bt used a vacuum pump to to create vacuum for the booster. could go for hydraulic assist like some of the chevy's have
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Old 07-05-2013, 05:37 PM
dodge dude94 dodge dude94 is offline
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I didn't know if he could adapt the vacuum pump onto the 4BT.
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Old 07-05-2013, 05:47 PM
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i think it might be mechanicaly driven by the engine and not belt drivin. installing hydro boost brakes is not that hard. just have to find the right parts.
http://ramchargercentral.com/technic...06/#msg1828106
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Old 07-05-2013, 08:16 PM
racer9 racer9 is offline
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I have a 6bta in my '96, so I know about that setup, in which the vacuum pump is bolted to the the power steering pump and is driven through it. My 4bta didn't come with that style of pump, and I was hoping to avoid spending a couple hundred bucks buying one. Electric pump is also available, again, a couple hundred bucks.
I had read on another forum about owners doing similar swaps and using the power master cylinder without the booster. It doesn't work for me, good pedal, poor stopping, as described in a couple 'sites I researched brakes on.
I went to a smaller piston master cylinder, as they recommended, to increase line pressure, I just don't know if that worked, yet.
I have a friend who has several older, rusted out, 1 ton GM's with hydroboost, which I will try to adapt if I have to, as my PS pump ran that type of system in the step van, that the motor came from.
When I was racing I didn't have power brakes, and it stopped good. Weight is about the same, racer had 4 wheel disc, and two master cylinders. I can't remember if they were 3/4 or 7/8, or one of each.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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Old 07-06-2013, 10:12 PM
racer9 racer9 is offline
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Well, the brakes are better, still not quite as good as I'd like. It does take a bit of foot pressure, but it does stop. The front brakes will lock if I get on them hard.
So, I'll try for state inspection, and see if anything else needs done.
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'96 Ram Cummins, turned up a bit, 306hp/743tq. 4X4, auto, Dunrite TC & VB, Intelligent Engineering billet input, Schwitzer S300g, 4" exhaust, homemade #100 plate, governor springs shimmed, homemade flatbed, Isspro gauges, bhaf.
'81 D150, 4BTA Cummins now rolling under own power.
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Old 07-06-2013, 10:12 PM
 
 
 
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