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Crawlink5's 4BT swap is done

BowtieBlazer

Diesel Powered
Joined
Jul 15, 2001
Posts
2,470
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Location
Baton Rouge, Louisiana
He's driving it to work tomorrow. Since he pulled it off the road he has added a 5.5" lift, d60, nv4500/205 twin sticked and 4BT installed. Nighttime carport shots....
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Rear of the truck
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front shot
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can you make out all 3 shifters? nv4500 and twinsticked np205
DSCN1224.JPG

the 4 cylinder monster
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doug showing me that his 4cylinder takes 11qts of oil
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one last spy photo, doug was mad he popped his hood for a photo shoot before he had cleaned it up some
 
Very cool! Any more info on the performance and the conversion? I'm very interested:)
 
I thought they had around 300 ft lbs off idle stock . I bet it moves itself real well . Proabably better thab a UPS truck :thumb:
 
BigJohnson said:
Very cool! Any more info on the performance and the conversion? I'm very interested:)
Doug will have to give you more info, but so far he is very happy with the fuel economy. A road trip this weekend showed that where he normally was burning 3/4 of a tank on the way there and filling up then coming home on another 3/4 of a tank burned less than half a tank of diesel there and back. His motor is newly rebuilt so he isn't worried about mileage much yet but he must be making in the 20mpg range if not better.

His conversion was nothing near stock, a nv4500 w/sm465 hydro bellhousing machined to fit, np205 swap along with the 4bt mounted on a lean. The only real bolt up stuff was the hydroboost, 5.5" lift and hydro clutch setup. I'll take lots more pics of mine as I move along.

here is where I stand....http://coloradok5.com/forums/showthread.php?t=133129
 
pauly383k10 said:
I thought they had around 300 ft lbs off idle stock . I bet it moves itself real well . Proabably better thab a UPS truck :thumb:
Image-7D9DB2C02F3711D9.jpg

They are real low end torque monsters, they are rated 305tq at around 1800rpms this particular dyno I believe is rear wheel not off the engine, so still a great transfer rate. I'll put it this way you can definately feel it!! I followed CrawlinK5 the other night through town in my 3.0L x-cab toyota which is really geared low from the factory,and he would walk away from me effortlessly from each traffic light, I would be speed shifting to catch up.
 
Yes I do love the 4bt. About 25 to 26 mpg highway.

1978 Chevy Blazer - Bonanza Edition
1986 Cummins 4BT rebuilt

4 wd NV4500 rebuilt from GearTechHD.com
w/hyd clutch
NV to 465 bellhousing with no adapter - machined at GearTechHD.com
11" clutch and pressure plate for BB chevy
Flywheel from Avant Salvage
pilot bearing

np205 rebuilt from GearTechHD.com - twin stick
NP to NV with no adapter - machined at GearTechHD.com

14bff rear 4.56 detroit with disc brakes
d60 front 4.56 open

Hydro boost from 1985 Blazer w/diesel

a 1" inch body lift would be nice but not absolutely necessary. A 5.5" spring lift in front and a 4.5" shackle flip in rear. the lift is necessary due to height of motor. No hood cutting but it is about 1/2" from hood.

26+ mpg highway ( it dropped a little when going to 4.56 and still have the 33" tires. I'll be going 35 to 36 next)
 
wildmouse216 said:
the orange plaid seats are cool too.

O-riginal equipment - 1978

power windows, locks, power rear window, tilt wheel, and cruise from the factory also.
 
-Motor - $1500 complete, that was a rare deal. Fresh rebuild, no miles (expect $4500)
-NV4500/np205/twinstick - $2500 got a deal for buying 2 sets (reg 2950) from GearTechHD.com
-D60 - $900
-Flywheel - $200? can't remember, but traded my auto plate for $100
-Machined Bellhousing - $250
-Rear driveshaft cut and new size ends - $340
-Clutch/PP/Throwout bearing $125?
-Radiator fan $60
-Gears and Detroit for rear $250
-Hyd master and slave - $90
-Hydroboost and Master - $175
-2" Drop drag link and 3" riser for d60 $220
=$6610

Misc about $1500 more. D60 bearings, brakes, calipers, oil of all types, hoses, pilot bearing, hydroboost hoses, you name it.

If you are going to do this strickly for the fuel mileage, you can't justify it. But this is my hobby.

You can go cheaper though. Use a sm465/np205 or a TH400. Throw it in and go.
 
crawlink5 said:
You can go cheaper though. Use a sm465/np205 or a TH400. Throw it in and go.
I'd stick with the 4L60. I also wouldn't put in the D60 front, and save a grand there. ;)

Yeah, you got a helluva deal on the motor. If I even decide to do a diesel swap (it wouldn't be just for mileage - I like wrenching for fun too!) it will probably end up being a turbo 6.5, unless I can score a cheap 4BT out of a bread van or something, :D Anyway, it's nice seeing other people's completed swaps to help you formulate your own plan. Good job on that 4BT conversion! :bow:
 
Do you notice any more vibration than a 6 cylinder? I hear they arent balanced as well as the 6 bangers and vibrate more, but you are the first person I've ever seen actuall put one in something.
 
Well - there are some vibrations :D . But I wouldn't have a 6bt after having the 4bt for a DD.

And I just got home (pulled) from a total clutch failure. This one I'll have to take pics of cause Its gonna be good. It was so bad I thought the bell housing had broken in half and the trans was hanging. I think the springs came out and then other things.
 
No pics yet. The springs in the clutch are not broke, but the clutch disc housing that holds the springs is busted up. Two springs came out. The springs still in the disc are loose and about to fall out. Fly wheel is ok. I have to look at the PP tomorrow. The fingers may be bent. I thought I would find the clutch material all off but it looks barely used like it should.

So the metal of the disc couldn't hold up. And I haven't even been off road yet :doah:
 
crawlink5 said:
Link to pics of clutch. See bottom row.

http://www.chevyblazer.net/chevyblazer/photo.htm

Here is the part number of the Centerforce clutch I think I'm going with:
DF024909

Big block application 12". Stage two street and strip.
Just a guess, but it is possible the excessive torsional vibration from the 4-cylinder diesel beat the $#!t out of those clutch springs. Are you using the stock 4BT flywheel, or something lighter? It seems to me a 4-cylinder diesel would need a hefty flywheel to dampen out the torque fluctuations. Heck, I remember em using a really heavy flywheel on the old odd-fire Buick V6's because of the torque fluctuations, and that 3.8L gas motor didn't generate near the torque of your diesel...

Just something to ponder :D
 
MaxPF said:
Just a guess, but it is possible the excessive torsional vibration from the 4-cylinder diesel beat the $#!t out of those clutch springs. Are you using the stock 4BT flywheel, or something lighter? It seems to me a 4-cylinder diesel would need a hefty flywheel to dampen out the torque fluctuations. Heck, I remember em using a really heavy flywheel on the old odd-fire Buick V6's because of the torque fluctuations, and that 3.8L gas motor didn't generate near the torque of your diesel...

Just something to ponder :D

The flywheel I'm using is the biggest I've ever seen. about 80 lbs. SInce the disc and PP is under warranty, I'm gonna try one more time. Not too happy with the discs, but I can't find anyone who'll say that the center section of the disc is HD. Only the clutch material.
 
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