Cummins 4BT & Diesel Conversions Forums banner

1 - 20 of 374 Posts

·
Registered
Joined
·
521 Posts
Discussion Starter #1
Been lurking on here for 2 years now and finally pulled the trigger about 2 months ago. I had been searching for about 6 months for a decent engine option and finally found one.

Donor vehicle is a 2006 Hummer H3 with the 3.5L. The truck has logged over 260,000 miles on the original engine and at the end of its lifespan was burning a quart of oil every 100 miles. As of today, the factory engine is out and the motor mounts are being fabbed to test fit the 4BT for the first time in a week or so. Project goals as follows :

- The engine will be bone stock except for 1) 3200 RPM governor spring 2) 12cm turbine exhaust housing. Goal will be to get a runner on the road, drive and log some baseline power and economy numbers and upgrade from there.

- Factory drivetrain will be utilized and be retained in the factory location. Unless there is something that just wont fit, the new engine will align with the existing driveline. Although the 4L60E transmission is not the heavy duty ideal, a few upgrades when it is out for service, a mild engine and no heavy towing planned should give a reasonable service life.

- Factory front IFS will be retained unmodified. This may mean some clearancing of the oil pan.

- Factory 4.56 gear ratio will be retained initially. This will put highway RPMs above the most efficient point of the engine, but baseline testing needs to be done before swapping any gearing.

- Intercooling will be done as an option during the install only if simple and feasible.

- Transmission controller will be converted to a standalone controller. The engine will require no electronics to run.

- A/C and power steering to be retained.

- Goal is 22-25 MPG highway with the swap

I'll post some pictures once my post count allows it.
 

·
Registered
Joined
·
521 Posts
Discussion Starter #2
Also, I've scoured the internet high and low and if anyone has done this swap, they have not published it here or anywhere else, so it looks like I'm the trailblazer.
 

·
Registered
Joined
·
384 Posts

·
Registered
Joined
·
3,391 Posts
I'd give a more detailed reply but headed out - sounds like huge potential for one GREAT BUILD here: thanks to the '5 P's Principle' - PROPER PLANNING PREVENTS POOR PERFORMANCE! This has SUCCESS written all over it, will look forward to updates here!
 

·
Registered
Joined
·
1,616 Posts
Donor vehicle is a 2006 Hummer H3 with the 3.5L. The truck has logged over 260,000 miles on the original engine and at the end of its lifespan was burning a quart of oil every 100 miles.
Serious? I wonder what's wrong with it. I've got 236K miles on my 454 and it does use oil, but not THAT much!

- Factory front IFS will be retained unmodified. This may mean some clearancing of the oil pan.
Is it trues that the Hummers got an iron front differential? ......or was that the H2?

- Factory 4.56 gear ratio will be retained initially. This will put highway RPMs above the most efficient point of the engine, but baseline testing needs to be done before swapping any gearing.
There are gear calculators online. I would think it would be much easier to do the swap now with no engine in the way. 4.56 gears are going to be way too low.
 

·
Vendor
Joined
·
504 Posts
Glad to see your build on here, cool project! I agree on the gearing, but I don't see what it would hurt to drive it first to get a baseline. 33" tires? or 35's?

.
 

·
Premium Member
1989 Jeep Wagoneer, 360v8, 727, stock for now,
Joined
·
2,632 Posts
4.56's will be great, with 38's.
 

·
Registered
Joined
·
521 Posts
Discussion Starter #10
Front differential is an aluminum case. They went to iron cases on the v8 Alphas in 08 I think. The alphas also came with 4.11 factory gearing so that may be a route to take in the future. I'm running 315/75/16 Cooper STTs (35s - they are on the small end about 34.5 actual). This is my second set. The first set I got 119,000 miles out of and this set has close to 80,000. The only reason I need new tires is I never rotated this set and my front lower ball joints are worn and in need of replacement causing faster than normal wear on the front. The torsion bars are turned up to gain about 1" in the front. I will see how the additional weight affects ride height. The alphas I think came with higher rate torsion bars if I need to go there also. I meant to take a ride height measurement before I yanked the factory engine but forgot. I should be able to tell by looking at the bump stops once everything is back in.
 

·
Registered
Joined
·
667 Posts
- Factory drivetrain will be utilized and be retained in the factory location. Unless there is something that just wont fit, the new engine will align with the existing driveline. Although the 4L60E transmission is not the heavy duty ideal, a few upgrades when it is out for service, a mild engine and no heavy towing planned should give a reasonable service life.

- Transmission controller will be converted to a standalone controller. The engine will require no electronics to run.
Using the 4L60E because you already have it makes sense. Using a standalone controller is a good idea so the money will already be spent when you replace the smoked 4L60E with a 4L80E.
 

·
Registered
Joined
·
521 Posts
Discussion Starter #13
Using a standalone controller is a good idea so the money will already be spent when you replace the smoked 4L60E with a 4L80E.
Make no mistake, I know the limitations of the 4L60E that is is not the ideal choice. However, the project is an exercise in swapping an engine of something that could have / should have been a factory option. The idea of a transmission swap, transfer case relocation, driveshaft modifications, axle and gear changeouts is not part of what I want to tackle right now.

Since the transmission has 260,000 miles on it I think I would be stupid not to go through it while its out. It will be getting a new torque converter anyway. I've talked with PATC who is local for me and they have suggested a few upgrades. At the minimum I will have some sort of warranty from the outset.

I've read a lot on this site and others about the weak links in the tranny. The advertised factory limitation is 360 ft-lbs. Yes I know that the 4bt will have torque at lower speeds and 2 pulses per rev, etc.... However, with a conservative setup of 300 ft-lbs, this thing will feel like a rocket compared to the 220 ft-lbs of the inline 5. If I can get the truck to get over an interstate overpass without losing speed and shifting out of tc lockup to get over, it will be a huge improvement.

That said, do you think I will keep my mittens off of the fuel pump screws? Probably not. I do realize by doing so though, that I will uncover the next weakest link. In this case, it may be the transmission.
 

·
Registered
Joined
·
3,391 Posts
My 4BT came out of a retired Frito Lay Grumann Stepvan. Can't remember but I think it was 22.5 foot, the larger one, not the 17.5' - regardless, it was a big mutha! That truck had labored along day by day on very mountainous, hilly terrain for many years, full of Frito Lay products. They weren't retired because of lack of power, no complaints there. The retirements were due to some management bozo's deciding that the best solution for 4BT Grumann Stepvans eating GM trannies like snack food, even 3 dead Pontiac Hi-Po TH475's like in my van, was to either retire them or yank the 4BT and install Chev 350's. UPS also went for the Chevy gasser engines.

Point is these 4BT's and especially 4BTA's have more than enough power to move a pretty large and heavy vehicle, bone stock!

I installed the 3,200 rpm spring and lost just a little bottom end, but gained revs on top. Didn't gain any power but really helped with NV4500 shift points! Then swapped the H1C turbo's compressor wheel and housing for HTT Stage II 56mm compressor and smaller compressor housing, a very moderate increase, which increased power noticeably. HTT Stage II is about the same as either HX35 or HY35, can never remember which one but whichever one is the better of those two, HX? After that I tweaked the screws and dialed it in to the new parts. That woke it up quite a bit. Then added a '90 Dodge Cummins intercooler, great! Very minor modifications overall.

I'd WAG that I went from 105 HP and 305 ft lbs torque advertised to about 140 HP and 400 ft lbs, gauging the performance. It's more powerful than the built Dodge 360 HP 360-3 that came out, that's for sure- ONCE YOU LEARN TO DRIVE THE TORQUE CURVE!

So, all that blab to tell you that very simple and fairly minor or moderate changes can result in an engine that gives every bit of the performance you need, plus outstanding, even incredible unbelievable fuel mileage.
 

·
Registered
Joined
·
1,505 Posts
Cool build. I am guessing you have the rotary style pump and not the inline. Either way depending on what it came out if it I would at the bare minimum pull the pan and check the bearings. You might be able to get a look at the bottom of the cylinder walls also. A $10 pan gasket can save you a lot of headache down the road depending on what you find. This site and competition diesel are great sources for these engines and info about them. Good luck with the build.


Sent from AutoGuide.com App
 

·
Registered
Joined
·
1,505 Posts
On a side note what did this engine come out of? Is it a vehicle or piece if construction equipment? That will determine what kind of rpm's you will need to stay around to keep peak power while at highway speeds and will determine what kind of govoner you have. The construction ones are build to run at a certain rpm where the auto one runs better through out the rpm range.


Sent from AutoGuide.com App
 

·
Registered
Joined
·
521 Posts
Discussion Starter #19
The engine is a CPL 1260 with a few modifications. It is a zero hour rebuild that I scored a great deal on shipped to by local freight dock.

The engine builder built the engine from the block up. Inspected everything through the build up, tossed anything that didn't meet spec and regasketed the whole thing. he also did the kdp, set pump timing, set valve lash, etc so I should be good to go. During the build he swapped the setup to a rear sump per my request. in addition, I think 1260 is an aftercooled build, but I've got a standard intake plate and the over the valve covers crossover pipe. I'll likely intercool it down the road.

A few more posts and I'll throw up some pics of the engine and my bare engine bay.

It does have the VE pump and as mentioned earlier, a 3200 spring is in the plans.
 

·
Registered
Joined
·
1,505 Posts
For your plans that sounds good I was just curious if it was an ag/construction engine or automotive based one. They have different gov on them and react differently. I noticed it when I took the 190hp industrial one off an put the 215hp one on my 12v. Probably could look at putting a 5 or 6spd Allison in there down the road. A friend of mine has one behind his cummins swap in a K3500 Chevy and loves it.


Sent from AutoGuide.com App
 
1 - 20 of 374 Posts
Top