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Discussion Starter · #1 ·
My swap is complete 4bta 120 from van into a 71 chevy 4x4. I decided to do it on 7 Sep when I saw a 4bt for sale nearby. I bought the engine on 8 Sep. Pulled the 400 on 9 SEP. Since then I've worked 2-4 hours every evening after work and about 12 hours last weekend. I drove it to work this morning. Total time wrenching to include pulling the 400 about 25-32 hours. The only thing left to do is fine tune the TV cable. It is very important to get lots of parts from the bread van. exhaust, air intake, motor mounts, etc.. My motor mounts are ugly. I have 3/8 plate welded to the frame with 1/4 plate gussets at angles to reinforce. Hopefully they won't break. I used the bread truck rubber mounts. The nuts are metric on these! Try to thread on a standard nut and you will spin one of the studs making it useless. I will post pics by the weekend.
I spent all evening today trying to do sound insulation. I bought "fatigue mat" from lowes(1/2 high density foam mat for factory workers to stand on). I contact cement and screwed 1 layer under the hood, and 2 layers to the floor of the cab. I got 1/4 foil backed foam air duct insulation and layered the firewall in the engine compartment. I then used foil backed fiberglass insulation with spray glue up behind the dash. All this helps immensly, but it still is noisy. Now the noise is from vibration mostly. Maybe Hydraulic motor mounts would be better than the bread truck mounts???
 

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Congratulations on finishing your swap.:beer: I really need to get off my ass.

The only thing left to do is fine tune the TV cable.
I would like to see pictures of how you hooked up your TV cable. Thanks.

Also It is very important to have the TV cable adjusted properly on a 700r4 or you could burn up the trans. I actually have a pressure gauge attached to mine to let me know if the cable adjustment is within specs. I imagine you are fine, if all you have to do is "fine tune" the cable. I've just seen a few people ruin these transmissions because they were not careful.
 

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Discussion Starter · #6 ·
patience...............Pics coming. I've spent my evenings doing sound deadening and playing with the TV cable. Having difficulty with my 700r4 adjustment. . I can't get it to upshift into second automaticly no matter what I do with the TV cable. I have to back off the throttle at about 18mph for it to shift. If I give it too much gas once in second it'll drop back to first. Tranny Governor has already had the heavy weights and heavy springs added. When I downshift to second at about 35-40 I get freewheel. A gas motor will rev so much higher with so little pull on the throttle. Maybe that has something to do with it. I'll get some pics on this thing soon.
 

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patience...............Pics coming. I've spent my evenings doing sound deadening and playing with the TV cable. Having difficulty with my 700r4 adjustment. . I can't get it to upshift into second automaticly no matter what I do with the TV cable. I have to back off the throttle at about 18mph for it to shift. If I give it too much gas once in second it'll drop back to first. Tranny Governor has already had the heavy weights and heavy springs added. When I downshift to second at about 35-40 I get freewheel. A gas motor will rev so much higher with so little pull on the throttle. Maybe that has something to do with it. I'll get some pics on this thing soon.
What stall on the T/C?
 

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Discussion Starter · #10 ·
Answers to questions:
Torque converter-I bought it from bow tie overdrives several years ago. It was bought as a stock stall converter. At that time they also sold a 2000rpm converter. It is not the 800 RPM "RV" converter I have heard is good for a diesel.

4BT compared to 400 small block-In order to be fair here I must say that my 400 was a strong running built 400. I beleive that most guys here that compare the 4bt to a v8 are comparing it to a tired old 305. The 400 was faster and had more acceleration by far. However It did require it to be revved up. The 4BT seems to pull as well or better at lower rpm. Exampl 45-60 mph floored in 3rd gear the 4BT accelerates well. If the 400 was in 3rd doing the same roll on it might not be as good. However the 400 has the rpm to jump down to 2cnd and push you back in the seat. At 60 to 70mph the 4bt holds it's speed better on slight rolling hills without adding power or downshifting. The big 3 changes are it burns half the fuel of the 400 which makes it practical to be a daily driver. The 2 downsides are increased noise and vibration. I have insulated against the noise, but vibration(which resonates in the cab);......The only thing I can do for this is possibly go get some soft rubber boat trailer rollers and use them for body mounts to try to isolate the body from some of the vibration.
 

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Discussion Starter · #11 ·
engine in truck pic

here's some pics people wanted to see:
Engine in truck-you can see the sound deadening on the firewall and hood.(1 layer fatigue mat 1 layer foil backed fiberglass. Contact cement(masonite countertop type) holds it in place.
 

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Discussion Starter · #12 ·
vacuum pump pic

This is a vacuum pump off of a early 80s caddy with a diesel. $10 at the junkyard. The pully was $5 off of the junk pully pile. I fabbed the mount which works, but it's not perfectly lined up.
 

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Discussion Starter · #13 ·
mounting 700r4 tc to flywheel

Here is a pic of the "flywheel ribbon" modified for a 700r4 TC. I slotted out every other bolt hole with my 4" angle grinder. There is "about" 1/4" gap between the ribbon and tC which I have been told is OK just bolt it up. 1 guy I know did this and it worked. I chose to use 1 washer to reduce the gap to about 1/8-3/16". I also used longer bolts for complete thread engagement. (almost pushing into the converter) A adapter ring would have been better, but maybe not really necessary. This has been in place for about 400 miles so far with no trouble.
 

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Discussion Starter · #15 ·
downpipe modification

The 700r4 is about 3" longer than the turbo 350. This gives you 3 more inches between the turbo outlet and firewall for the downpipe to make the turn. Mine makes the turn with about 1-1.5" to spare with the following modifications. First bash the firewall in with a hammer as much as you can. Second cut out all the straight pipe between the clamp and the turn on the downpipe. Then reweld. I know this probably negatively effects performance and EGT's slightly, but It was easy and I really didn't want to cut and weld my firewall. What would be really cool would be if someone on this forum would make some "offset turbo flange mounts that would sandwich between the manifold and turbo and allow the turbo to be turned maybe 45 degrees so that you wouldn't need a 90 degree bend downward from the turbo.
 

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Discussion Starter · #16 ·
motor mounts

First I lowered the motor into the truck and bolted it to the tranny to see where I needed motor mounts to be. I marked things and pulled it back out. Then I removed the crossmember. It is possible I could have made use of the stock crossmember somehow, but I needed the engine lower to give me room for the downpipe to clear the firewall. I also did not want to have to remove the engine in order to take off the oil pan. I started by welding 4X 3/8" tabs on the lower frame rail as shown in the pic. I then lowered the motor with the rubber bread truck mounts bolted onto it down into the truck. The right rear metal tab interfered with the starter and future removal of starter if needed. I pulled the engine again and then I cut out some of it on the red line you can see. I then lowered the engine back in with the rubber mounts loosely bolted on and positioned it so the rubber mounts were between the metal tabs I welded to the frame. Then bolted up the tranny. I then bolted the predrilled 3/8" plates to the bottom of the rubber motor mounts (this plate was now flat against the bottom of the 3/4" spacer on the bottom of the tabs welded to the frame. I welded this in place. (It is easier to have plates welded after the motor is in than it is to try and weld in plates and get the motor mount bolts to line up with holes). After this was done I added some 1.5X1/4" diagonal reinforcments. My welding was done at odd angles with a spool gun and flux core wire. It is ugly. I gobbed it on heavy since it's not pretty. Hopefully it won't break. It's hard to get a picture of it now that the motor is in.
 

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Discussion Starter · #17 ·
pic of whole truck

OK here is the whole truck. This pic was taken before the 4bt. Now it sets about 1" lower in the front. Truck is a 71 longbed 4wd. It's a nice street truck that sees the occasional muddy road or maybe hauls corn to the deer stand. It's not a "offroad toy". For the past year I've been driving a ford ranger with a 4cyl on my daily 55 mile comute. The chevy with 400 was my weekend truck. I intended to sell it and get a boat, but noone was interested. A good deal came up locally 1999 4bta 120 that I could still see run in the truck for $1700. So I did the swap. Now the chevy will be my daily driver and I will sell the ranger. If I can just get some of the Vibes resonating in the cab down a little bit.
 

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go to the roofing section of Lowes, and they have small rolls of whats called "peel & seal", its alot like dyamat. warm it up with a hairdryer, and stick it on the metal. it does a wonderful job of dampening vibrations in large metal sheets.
 

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Discussion Starter · #20 ·
Mpg

My first 150 miles or so of driving was 50/50 city highway with highway being 55-60mph. I got 20mpg. This is assuming a 10% odometer error due to 31" tires. (I will check with GPS today maybe more). The next 200 miles of driving was 25/75 city highway driving. I got 22mpg assuming a 10% error. I was really hoping for around 25 with this swap.
However I have done a couple mods. First I put in the 3600 rpm spring which really does help driveability with the 700r4. I turned in the full power screw about 1/3 turn. I turned the smoke adjustment in 1 turn. This helps when you start out, but I may undo this change and recheck mileage.
My TV cable relationship makes me have to go faster in 1st gear than I would like before it will shift. Which may be affecting my mileage. I beleive my geometry is causeing my TV cable to be pulled too far too fast. It's about 2" of TV pull for 1" of throttle cable pull. I need it to be more like 1.3" : 1".
 
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