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Discussion Starter · #1 ·
Hello Everyone. I have a 85 Chevy Truck that I'm trying to swap to a 4bt. It had a 350 SB Chevy in it originally. I purchased a Transmission adapter so the engine is straight up and down and not tilted with the stock GM adapter plate. Everything bolts up nice and looks good and I was going to fab up some motor mounts when I was looking at the clearance on the exhaust of the turbo. I do not have enough room for the exhaust exiting the turbo and the firewall. Only 3 inches. (I could fab up a exhaust 90 that might work but it would be very restrictive) My 4bt has the exhaust manifold where the turbo is between cylinder 3 and 4 in the downward position. I think my options are:

1. I could get a exhaust manifold where the turbo would be between cyl 2 and 3 but then I have no room for the oil filter. Is there an oil filter relocate kit? If I do this which exhaust manifold should I get?

2. Move the entire engine forward and fab up some transfer case mounts and have the driveshaft's lengthened and shortened. (Lots of work...)

3. Pound in the firewall and ditch my A/C. I don't want to do this....


I know someone has to have done this before. Is there a good way to get a 4bt in a 80's chevy truck while keeping the A/C and everything functional without a lot of modifications?
 

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Discussion Starter · #3 ·
Wouldn't that put the turbo in the Front/Upward position with the and get in the way of the alternator and water lines? I'll have to look. I think I can attach a photo of what I have. Hope it works. ATTACH=CONFIG]56242[/ATTACH]
 

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Discussion Starter · #4 · (Edited)
Here is some progress updates on the 85 Chevy Pickup. After some thought the engine was lowered down as much as possible to allow for the exhaust to clear the firewall. We then fabricated some motor mounts and a new cross member. There had to be a compromise between lowering the engine for the exhaust and clearance of the oil pan. Here is what we fabed up.
20150724_105545.jpg

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Discussion Starter · #5 · (Edited)
We then started to work on the clearance issue with the oil pan. Also the drain plug was on the side with the 4x4 axle under it. This would make for a big mess at each oil change. I was unable to find an oil pan with the drain plug on the drivers side of the oil pan. So we cut out the oil drain plug and cut out the clearance needed in the oil pan.
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The drain plug was then installed on the drivers side.
Here is the finished product.
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Now the problem was that the oil pickup tube was in the wrong location. I searched and could not find any real solution online. Everyone just said that they bent the original tube to make it work. I did not like the idea of "bending" the original tube. It would have taken a lot of bending to make it even close to working. My solution was ordering a 5.9L pickup tube and cutting it in 2 locations and shortening the tube. This moved the tube over to the drivers side of the engine which I wanted and maintained the stock bolting to the engine for support. Here is the finished product.
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Here it is on the engine.
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Be sure to test your welds with a fluid to make sure they are water/air tight!!!
Then the flywheel cover was cut so it would fit properly.
20150727_163638.jpg
 

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Discussion Starter · #7 · (Edited)
Now we are working on the wiring. I was looking at how to wire up the fuel shutoff and discovered that I have a KSB. So now I have been searching for proper ways to wire up the KSB. It sounds like there are 2 types. I think I have the wax type.
20150818_1053122.jpg
 

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Believe you're correct about the KSB. That type just requires a 12 volt hot lead when the switch is on just like the start/stop solenoid. The other type will have a temp switch mounted in the head to control it. You don't have to connect it, but if you live in colder climate it help the engine by advancing the pump timing.
 

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Looks like you're making good progress. Curious why the flywheel cover didn't fit.
Char, my, flywheel cover didn't fit either. It was what appears to be the same unit that john has shown us pictures of. Mine originally came off of a 6.2 diesel/700r4 combo, and now I'm running a 4bt/4l80e. I had to saw the front lip off of the cover, the back bulge which hit the transmission, and reweld some tabs where the bolt-holes didn't all line up.
John,
Cool build so far. I did this swap into a 1982, and I've been driving it since Memorial Day. I decided to keep my transmission/transfer case crossmember in it's original location, so my drivelines wouldn't have to change. With the 4l80e being longer than the original 700r4, I just moved the engine forward accordingly and fabbed my engine crossmember/motormounts. If you have any questions let me know!
 

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Your engine mounts and engine position in relation to the firewall look identical to my 78 k10 project. My k10 has a 3" lift so I did not modifiy the oil pan.

I am considering moving the whole drivetrain to my K5 blazer with no lift. I had the same plans for the oil pan and oil pickup tube.

Good work.
 

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Discussion Starter · #11 ·
I got the motor to run today! Great feeling when it fired up without any issues!

I had the original 700R4 rebuilt just a few years ago. My original plan was to put a 4L80E behind the 4BT but since the old 700R4 was not that old I figured I would run that until I had problems then I would put a 4L80E in the truck when the 700R4 quit. I did buy a 1200 stall converter for the 700R4.

j2j, I might have to ask you someday when I put the 4l80e in what transmission controller you used.

We are now putting the front clip back on. Things are starting to take shape fast now. The next things to tackle are water hoses, throttle cable linkage, air intake filter and to decide weather to use a mechanical fan or put 2 electric fans on the radiator. I am leaning towards 2 electric fans as the water pump pulley is off center of the truck and will not work well with the fan shroud.

Does anyone have experience with the 700R4 TV cable linkage hookup with the 4bt? I think I am going to have to make a rocker arm of some sort to make it have the correct geometry for the transmission cable.

Thanks everyone for your help!!
 

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I got the motor to run today! Great feeling when it fired up without any issues!

I had the original 700R4 rebuilt just a few years ago. My original plan was to put a 4L80E behind the 4BT but since the old 700R4 was not that old I figured I would run that until I had problems then I would put a 4L80E in the truck when the 700R4 quit. I did buy a 1200 stall converter for the 700R4.

j2j, I might have to ask you someday when I put the 4l80e in what transmission controller you used.

We are now putting the front clip back on. Things are starting to take shape fast now. The next things to tackle are water hoses, throttle cable linkage, air intake filter and to decide weather to use a mechanical fan or put 2 electric fans on the radiator. I am leaning towards 2 electric fans as the water pump pulley is off center of the truck and will not work well with the fan shroud.

Does anyone have experience with the 700R4 TV cable linkage hookup with the 4bt? I think I am going to have to make a rocker arm of some sort to make it have the correct geometry for the transmission cable.

Thanks everyone for your help!!
John, I used the TCI EZ-TCU. This is the only controller I have experience with, obviously. I am not 100% satisfied with it, though. We could visit about that later though.
I would highly recommend a mechanical fan. I have two electric fans on my Camaro, and I am just skeptical that they move enough air. I used the stock clutch fan off of the 4bt (Freightliner MT35) and built my own custom shroud out of fiberglass. Not too complicated of a job, just time consuming. I could also describe the process if folks are interested. Good luck man, these projects are totally worth it once you get it going!!!
 

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Discussion Starter · #17 ·
Jeep, I used 1/4 inch steel to make the box frames and mounting areas.

j2j, I would definitely have to build a custom fan shroud to make a mechanical fan work on my project. I was thinking that electric fans would work but you may be right in they would not have enough CFM draw to keep the engine cool. I have already purchased the electric fans so I guess I will try that route first.

More progress on the build. I managed to find the lower radiator water line that fit perfectly! I was quite surprised. The number is a Gates 21285. It fit the 4bt and the radiator with no modification necessary. The upper radiator hose is going to need some modification as it is a long distance and I could not find a hose that will work. My plan is to cut the hose and insert a metal pipe in the middle to increase the length.

I wish I could upload some more photos of my build for everyone to see but apparently I do not have any more storage available on the forms.
 

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Throttle Valve cable setup & electric fan shroud pictures

Hope this might be helpful.

The Throttle valve cable setup was a picture I found a few years back on the internet

The shroud I built to fit with a Taurus two speed fan.
The radiator is a GM crossflow.
The high speed has not needed to come on, but I haven't wheeled this setup off road yet.
If I remember right, the Taurus fan setup is about 2K cfm on low, and about 4K on high. Plenty of info on the internet.
$20 at a wrecking yard, and Doorman makes a great OEM quality replacement motor.

The shroud is just aluminum plate and 2" aluminum "L". Cheap and readily available.
If you go Taurus fan, You'l want to run a good 80A relay for high speed, and a 40A for low. Fuse accordingly.
There are good schematics to do this on the web, as it is a very popular fan setup.



 

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Discussion Starter · #19 ·
Comanche Scott, Wow great photos. I hope to work on fabricating something up for the TV cable and those photos are a great help!!!! I also found this thread that had some nice photos of another idea of hooking up the TV cable. The form will not let me post a link to another post in the form until I have at least 10 messages. So you will have to make the link work manually.... "4btswaps.com/forum/showthread.php?52098-My-47RH-TV-cable-linkage.".

That first photo of the throttle linkage also has the a/c compressor in the location where I plan to make a mount for my a/c pump. I am not going to get my a/c working now I will tackle that this winter when I have more time.

I definitely like the metal fan shroud and the Taurus fan! That setup looks super easy to make and it looks very clean. Thanks for sharing, everything helps!
 

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Another shroud style to consider

Glad to help.
yeah, this was definitely the easiest one I've built.

If you want to do a more traditional looking shroud, here is one I built using twin 12" fans for a supercharged small block with A/C.
I modified a repro shroud, cut an aluminum plate, glued and screwed it to the to the shroud, and mounted the fans offset. Also on this one I added some bypass vents for freeway driving.
This was done to maintain a more stock-ish appearance for the vehicle, but the whole front end, from the radiator support back was changed to get more airflow through the oversized radiator (this was actually a big project for such a hidden effect).
The twin 12" fans pull just under 3K cfm together, and to get maximum cooling need to be very tight to the radiator.

Any way, hope this will give you another idea for something fun to do.
It is always fun to see what others do, so hope you'll post up pictures of your build! :beer:



 
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