Cummins 4bt Luber Build Thread(Off road video added)!!)

[Dbteak]

Well, I'm glad u tried out a the other gears! Where they just too tall? Where u not getting into ur turbo???

The 3.00 gears were a bit too tall for my liking. I didn't really see a increase in the mileage so I decided to just put the 3.50 gears back in. I couldn't really justify the cost of 2 sets of 3.25 gear or even replacing the front with 3.00 gears. The 3.50 gears will give me 2050rpm's at 65 mph and a little bit lower crawl speed and I am happy with that. As far as getting into the turbo it really wasn't that noticeable but with the lower gears I always seemed to putt around town at a lower RPM. One thing I did notice is that when the engine was below 1880 the vibration was a little harsh. I don't know if it was an engine thing or something else in the drivetrain and I wasn't worried about the vibration it was just that it was noticeable.

Doug

 

[Dbteak]

I dont know if i have commented on this one or not but I have 3:55 gears with a nv 4500 and 35 inch tires, when I am on the intertstate i can kncok back 32 mpg, its usally 26 to 28 runnin around town.

My mileage comes in at a steady 24.5 with about 60% city driving. It is strange that the mileage is so different.

Doug

 

[big a]

I sure do appreciate all ur write-ups!!! Ur saving me a ton of time later in my build!!! I won't have to go to all the research to get to where u r! Thx a ton for sharing!!!!

 

[big a]

Sadly, I've changed my mind on leaving mine uncut

I love the way urs came out!!! I'm putting n a wider seat to accommodate my 3 kids, so I have to cut 4.5" into each wheel well. I'll write up on my thread later what I'm doin. I do not like the looks of fender flares, so I'm gonna graft in some front fender cutouts.

Your write up on ur gears sure gave me confidence to stay where I'm at with stock gears!

 

[nash]

Nash

What Hydroboost setup did you use Doug?

Chris

 

[Dbteak]

I bought the set up from vancobps.com. I really have no idea what they sourced the pieces from. I usually follow up with the vendors and ask where they sourced the parts but I never did with them. I really didn't want to deal with them as it took 3 months and a few phone calls to them to get it. I was missing 1 fitting also. He said he was waiting for parts but every time I called he acted like I was bothering him. On the positive side it does work well.

Doug

 

[big a]

How's that aluminum bumper coming along???

Im anxious to see how it turned out!

 

[Dbteak]

The bumper is on the bronco. It took a lot longer to build that I thought. I spent a lot of time at 200 amps on the tig welder. It was a fun build though. I still need to finish sanding it to get the finish I want and build the tire rack. I am not quite sure I like the dimensions as I kind of used the Hanson bumper and tweaked it to make it fit the 2" body lift.

Doug

 

[big a]

That looks great!!!! I especially like the elk rack in the back corner of your shop!

 

[ProjectCumminsBronco]

I was asked about more info on the intercooler that I used. I bought it off E-bay from CRXracing. I am not sure how they advertised it but I measured the core and it is 10" tall, 20.5" long and 2.5" thick. I used the silicone 90 deg elbows and it fits like a glove around my radiator. I also cut out the radiator core support to fit the intercooler about 1" into the engine bay. I probably could have moved it in about another 1/2 inch. I plan on taking some temperature measurements to see how efficient the cooler is. Here are some pics of the intercooler.

Doug

Would this happen to be the kit you bought?

http://www.ebay.com/itm/JDM-SPORT-2...es&fits=Model:CRX&hash=item1c318c5df4&vxp=mtr

 

[ProjectCumminsBronco]

I didn't like the how close the down pipe was to the floorboard so I made a new one this weekend.

Also a pic of the throttle linkage.

Doug

What did you use for your throttle linkage?

 

[Dbteak]

Krause asked me the same question. This is what I wrote to him.

I used the longest Lokar throttle cable and it was very easy to install. On the first picture you can see how I routed it. It is the black cable below the intercooler piping. I put as big of a bend in it as I could. I used the same return springs that came with the 4bt. The throttle is very smooth and factory like. It hasn't work through yet as of 9000 miles.
The bracket that the engine side of the cable is attached to came with the engine and is where the stock throttle cable attaches. This set up was for the P7100 pump as it may be different for the other pumps.

Doug

 

[Dbteak]

Would this happen to be the kit you bought?

http://www.ebay.com/itm/JDM-SPORT-2...es&fits=Model:CRX&hash=item1c318c5df4&vxp=mtr

The piping looks about perfect as far as what I used but the intercooler looks a little short. I think the stock bronco radiator core is 19" with about 4" of tank. I will get a overall width of my intercooler.

Doug

 

[Dbteak]

The piping looks about perfect as far as what I used but the intercooler looks a little short. I think the stock bronco radiator core is 19" with about 4" of tank. I will get a overall width of my intercooler.

Doug

I looked at my intercooler and it is about 26". I think that kit would work perfect.

 

[Dbteak]

Tested my gas mileage a few weeks ago. 705 miles on one fill up. I figured I had 3 gallons left. I didn't want to run the diesel dry. They can be a pain to bleed the air out. That's a 23 gallon BC tank and a Tom's replacement tank.

Doug

 

[big a]

Tested my gas mileage a few weeks ago. 705 miles on one fill up. I figured I had 3 gallons left. I didn't want to run the diesel dry. They can be a pain to bleed the air out. That's a 23 gallon BC tank and a Tom's replacement tank.

Doug

Man, that's awesome!!!! I bet you were grinning ear to ear!!!!!!!!!!!!!!!!!!!!!

I can't wait to get mine on the road. I was filling my truck up with gas ystrdy and just stared at the green diesel pump and dreamed I still have a ways to go on mine. My goal is next summer. Your thread has sure helped me a ton!!! Thx!!!

Hopefully, one day, I'll be overlanding with the family and our paths will cross! I'd love to see your rig!

 

[Dbteak]

I was asked about some measurements for my intercooler and I though I would add them to the thread.
The core on my intercooler is 20 1/2" wide x 10" tall x 2.5" thick. Total overall width of the intercooler is 27".
I use silicone 90's off the intercooler and the overall width with the 90's is 32" and the inside measurement of the 90's is 26 1/2". I have about 2 1/2" of space between the radiator tank and the inside of the 90's so I could have gone with a 25" overall width intercooler. I am not using a stock bronco radiator.
As far as going wider I am already up against my air box and very close to my battery so I wouldn't go much wider.
Using a taller intercooler you would have to move it back further into the engine compartment and that would have caused me clearance issues with my electric fan and fan pulley and I would have to move the engine back. I have about a 1/2" now.
I tried to get some more picture but trying to get picture through all the wires and stuff they didn't really turn out that good.

Doug

 

[Dbteak]

I did finish my front bumper though. I am going to start another thread on the bumpers.

Doug

 

[big a]

Dang that's nice work!!!!!!

I had to take a break from mine. We decided to sell our house. We're buying a home on some land where I can build a shop!!! Hopefully I'll b able to get back to it in the next cpl mos!

 

[big a]

Hey Doug, how's the bronco running? Anymore improvements?

I had to break from mine for a bit. I'm still in the middle of remodeling our new-to-us home. Good new is though, I've broken ground on building a shop in the back yard! We've been getting quite a bit of rain, ice and a little snow, so it's slowed progress up a bit. Man, I'm ready to get back to working on mine!

Hope things are goin well for you!

-Andy