My work computer is blocking your link so I can't see what you are pointing to.

Your estimate of a nickel each is about right

 

It was just a reference picture to your gallery.
OG

 

A guy at work turned me onto your project (Thanks Joe!).

I'm almost to year 9 in my 2.5L TJ Wrangler. That's ~3000 times that I've been reminded that it is slow. I get ~15-18mpg and have a tough time on the freeway unless I shift a lot, so I've been contemplating something like this for a while. I learned that the 4BT (bread truck mill) is pretty loud and heavy, and makes for an expensive swap once you have the whole driveline done.

The 3.3 looks perfect. Not only that, I have a small chance that I can get a killer deal on a B3.3T. I'm going to start looking for a 97-05 4.0 Wrangler with a dead engine. Your project looks very well done and you've contemplated the important engine characteristics thoroughly instead of just throwing something in and cranking up the fuel. I hope you have given yourself a big pat on the back for going through the growing pains first on this particular swap.

A few questions for you (you seem awfully patient and helpful):
-What are the big things you would do differently?
-If you had a front mount intercooler for free, would you still use it (and the possible additional lag)?
-Is your engine free from any computer control? If not, have you discussed computer tuning options with a Cummins tech? (The one I might be able to get may have an electronic "throttle")
-Did you just hook up a cable to the factory pedal?
-Can you tell me (ballpark) what you paid for the bellhousing and adapter plate?
-What did you do for the clutch setup?
-Did you have any trouble with vertical alignment to the stock mounted tranny?
-Can you briefly describe your exhaust system? Did you remove the cat, use a stock muffler, etc.
-Any sign that you will see transmission or axle failures in the future?

Feel free to comment on my thoughts:
-At first I thought I would want the 6 speed manual, but the AX-15 actually has a higher ratio in 5th gear than the 6spd does in 6th. Either would be appropriate.
-I'd like to run a microcontroller to monitor the temps and vitals. This would display on a weatherproof readout via CAN. I could perhaps incorporate other functions such as cooldown timer, warmup mode, pushbutton start, etc. This does introduce a potential failure mode into the system.
-I'd aim for ~32" tires. This makes lifts modest and may help out the top end speed. I wonder what effect it would have on fuel efficiency. I'd be curious to see BSFC numbers for 75 mph at different revs/tire sizes.


Thanks in advance for any thoughts from you and other forum members. I studied engines for 2 years in college and know how many variables are at play to gain good performance and reliability. Each of your little changes can have a profound effect on the others. People don't realize how much tuning goes into a production vehicle. Let's just say that I have lots of respect for the work you've done so far.

 

Thank you very much. My background isn’t in any type of mechanical training (my undergrad, grad and professional work is in RF and millimeter wave integrated circuit design) so this was kind of a big step for me.

---------------------
A few questions for you (you seem awfully patient and helpful):
-What are the big things you would do differently?
---------------------

The GM flywheel needed for the Phoenix adapter is the newer style which has a slight balancing weight internal to the flywheel (my understanding is this is done so the engine’s didn’t have to include the balancing). In hindsight I should have ground this off so the flywheel was balanced, but I was hedging my bets so if the swap didn’t work I wanted to be able to sell as much of my parts as possible. Also, the flywheel has a toothed starter ring on the outside to engage an automotive starter. The B3.3T has the starter integral to the engine so this ring isn’t needed and could be removed.

I underestimated the amount of travel the front axle would experience on my first go around with setting the height of the engine. I got a slight dent in my oil pan when I hit my first big bump. I then raised the engine a bit, put on the slightly longer, heavy duty shackles ( 1 inch longer for 0.5 in more clearance), and lengthened my bump stops on the front.

---------------------
-If you had a front mount intercooler for free, would you still use it (and the possible additional lag)?
---------------------

Free is a good price. I would give it a go. Doubt you will introduce much additional lag if it’s not too big, but I am no expert in this area.

---------------------
-Is your engine free from any computer control? If not, have you discussed computer tuning options with a Cummins tech? (The one I might be able to get may have an electronic "throttle")
---------------------

No computer what so ever. It needs a signal for the fuel shut off solenoid so the injection pump can get fuel. The starter needs the crank signal and a 12V to crank the engine and get it going (I’m using the same cables for the starter solenoid and battery connections, but needed to add some length to reach).

Are you sure the one you are looking at is the B3.3T and not the QSB3.3? The QSB is the new common rail version which has electronics on it. It also has an intercooler already (think it is air to water).

I have a lot of unused electrical connections under the hood. My “check engine” light is on constantly. I covered it up with black electrical tape.

---------------------
-Did you just hook up a cable to the factory pedal?
---------------------

Yes. Turns out the accelerator cable from the factor pedal was exactly the right length to connect to the B3.3T’s fuel pump. I remember discovering this and laughing out loud. If you have the 4 cylinder gas engine it might be different than the 4.2 inline six.

---------------------
-Can you tell me (ballpark) what you paid for the bellhousing and adapter plate?
---------------------

Have the receipts at home. Was thinking the phoenix casting adapters were ~$190. The Advanced Adapters AX-15 to GM full bellhousing kit should be easy to find on the net.

---------------------
-What did you do for the clutch setup?
---------------------

The Advanced Adapters instructions cover what’s needed. Mine was a bit more complicated as the 1990 AX-15 had the internal clutch release mechanism. This caused some headaches when trying to connect the factor clutch line to the new external Toyota cylinder that AA calls for. Had to go to a specialty hose place (Custom Hose) to get some brake line with the right adapters to mate these things together.

---------------------
-Did you have any trouble with vertical alignment to the stock mounted tranny?
---------------------

No.

---------------------
-Can you briefly describe your exhaust system? Did you remove the cat, use a stock muffler, etc.
---------------------

3 inch straight pipe. Went to Professional Muffler and had them do a custom exhaust. It cost ~$150. You do need a special Cummins turbo exhaust ring thingy (sorry for the non technical name) to go from the turbo outlet to an exhaust system. It’s the same part that’s used on the 4BT’s and 6BT’s. I have the specific name and part number at home in my folder but can’t remember it now.

---------------------
-Any sign that you will see transmission or axle failures in the future?
---------------------

The tranny has 120k on it right now. It was used as a snow plow vehicle for several years at an auto dealership before I got it (it came with a fully hydraulic operated plow). The previous owner that bought it from the auto dealership didn’t use the plow that much. I got the plow (sold it to a friend) when I bought the jeep and it is one heavy pig. Took three big guys to load it into my ¾ ton Ram. That’s a lot of weight on the front axles.

Anyway, the synchros in 1st and 2nd seem worn pretty good. When it’s cold it’s a bit difficult to get into 1st and second if your rpm’s are very high. Other than that the tranny and axles seem to be doing well and haven’t gotten worse for the last 9000 mls that the Cummins has been in it.

---------------------
Feel free to comment on my thoughts:
-At first I thought I would want the 6 speed manual, but the AX-15 actually has a higher ratio in 5th gear than the 6spd does in 6th. Either would be appropriate.
---------------------

I used what was in the vehicle to save $. The gear ratios are more than adequate for my needs. A six speed would be nice though.

---------------------
-I'd like to run a microcontroller to monitor the temps and vitals. This would display on a weatherproof readout via CAN. I could perhaps incorporate other functions such as cooldown timer, warmup mode, pushbutton start, etc. This does introduce a potential failure mode into the system.
---------------------

Sounds cool. You will need to add your own sensors to the B3.3T to get this info. The QSB3.3 would have this info available to you via its computer.

---------------------
-I'd aim for ~32" tires. This makes lifts modest and may help out the top end speed. I wonder what effect it would have on fuel efficiency. I'd be curious to see BSFC numbers for 75 mph at different revs/tire sizes.
---------------------

The only BSFC #’s I could find were for 1600rpm and 2600 rpm and I posted those in the thread. If you assume a linear slope between these points you could get an estimate for what it’s doing for any given rpm at max fueling.

I made a spreadsheet which takes the published coefficient of drag (Cd is 0.56 for the hard top YJ I believe) and frontal area for a jeep and calculates the hp needed to overcome wind resistance as a function of speed. It’s ugly. At 55 a stock jeep needs about 20 hp for wind resistance. At 70 it needs 40hp. At 70 into a 30 mph wind (100mph) it needs 118 hp. If you add bigger wheels and raise your vehicle you are just going to need more power.

I've done some stuff to improve my Cd as of late. The vortex generators I talked about already, but I've also just made my own front ground skirt to reduce turbulence for the air going under the jeep. Also made some skirts to block the huge gaps between the bumper and the wheel wells which would seem to catch the air. I'm hoping to improve my mpg's this summer to the mid 30's instead of the lower 30's.

---------------------
Thanks in advance for any thoughts from you and other forum members. I studied engines for 2 years in college and know how many variables are at play to gain good performance and reliability. Each of your little changes can have a profound effect on the others. People don't realize how much tuning goes into a production vehicle. Let's just say that I have lots of respect for the work you've done so far.
---------------------

I'm toying with the idea of getting 4 new injector nozzles and having the holes modified a bit (this way I could go back to the stock nozzles if I don't like the modified ones). My EGT's and boost seem to indicate that I have enough air to support about 5-10% more fuel (assuming a linear relationship between EGT's and fuel which may not be correct). I'm thinking that this would allow me to flow a bit more fuel without introducing the rpm hanging issue I get if I turn the fuel pump up anymore. Any thoughts on this?

 

We usually make fun of EEs and say that they can't change a tire unless there is a button on it, so you are above the curve. I'm pretty sure the EE's have some equally kind things to say about MEs. Interestingly enough, you've solved the mechanical hurdles, while I will have mostly electrical/software hurdles if I get the engine I'm looking at.

I took a look at the machine with the engine I'm interested in. I am sure now that it must be the QSB3.3, as there are electronic injectors and a huge ECU. This is good and bad; good that it can be configure electronically and that all of the vitals will be available over CAN, bad that the simplicity of yours is not an option. In the end I think it could be nice because it could mitigate cold start issues and smoking. The intercooler on the machine looks fairly large, but it just might fit in the (rather large) gap in between the Jeep grill and radiator.

I wondered how you solved transmission alignment issues as you moved the engine up and down for fit. Regarding oil pan clearance: I would have to compare the TJ travel to that of a YJ but I'm guessing it will be an issue, especially if I ever disconnect the sway bar. I'm thinking that it might work to fabricate a recess into the oil pan for clearance. That's one of the things I can't really design well until I have the parts in front of me. I will have to take it on faith that the problem can be solved. I need to take a critical look at the YJ vs. TJ suspension.

I looked up the AA bellhousing. Not cheap, but surely better than fabricating something.

Does Cummins offer an engine heater for parking on cold nights? Perhaps that would help the high oil pressure on startup. A cartridge heater might work to heat the oil in the pan.

When I get some time I will dig back through my old textbooks. I think you may be able to calculate a theoretical EGT with detailed knowledge of engine dimensions and input parameters (air pressure, temp, etc.). I'm not making any promises, but if I can find out how I will be happy to make a spreadsheet for you. I did most of that kind of analysis in college with rather expensive software that made it easy (I know longer have access to it). Anyway, if you think you have excess air you should in theory get more power with more fuel, and if you think your pump can squirt more through bigger nozzles it's worth a try. Wouldn't it be nice to have a dyno for all of this speculation? I'm certainly no expert, but I get the feeling that the turbo will fail from high EGTs before you grenade the engine (not that a turbo is cheap to replace).

 

Let's not start an EE/ME war

The common rail version should be better for cold starts, but you will probably still want the intake grid heater. My 04 5.9 Cummins with the common rail still uses a grid heater for cold starts.

I'm not sure if they offer some kind of engine block heater or not. I don't recall seeing that option. I'm really not bothered anymore about the oil pressure as the engine was designed to handle it. After thinking about it wouldn't the higher oil pressure get the internal parts lubricated faster at startup than if the pressure was lower? Pretty sure fluid flow through a given orifice is somewhat proportional to pressure.

The AA kit includes more than just the bellhousing. Lots of pieces in there . . .

An engine theory question for you. What are your thoughts on my observation about blocking off the intercooler during cold weather and the observable increase in mpg? Doesn't this seem to contradict the Carnot Cycle? Or is it possible that some second order effects are causing this (incomplete combustion due to too low of temperatures ?)? I have a hard time trying to control variables since environmental conditions change so radically from tank to tank (wind, temp, snow, slush, rain, etc.).

 

Don’t think I’ll need to modify my injectors after all.

Been reading through the Bosch “Diesel Distributor Fuel-Injection Pumps” technical instruction manual for the VE pumps. I never fully appreciated the complexity and beauty of these little pumps. Fascinating. Anyway, in the chapter titled “Add-on modules and shutoff devices” there’s a section called “Torque control”. In this section it describes different ways the fuel pumps fueling characteristics are modified to tailor a fuel curve. The method my fuel pump uses to do this appears to be “positive torque control”.

The positive control refers to the pump being setup to deliver enough fuel at low rpm’s to achieve maximum torque and needing to reduce fuel at higher rpm’s to prevent “the engine being unable to completely combust the excess fuel injected at higher speeds and smoke would be the result together with engine overheat.”

MMMWWAAHHHAAHHAAHHAAA!

More specifically, it appears it is using “positive torque control using the governor lever assembly” and “The decisive engine speed for start of torque control is set by preloading the torque-control springs.” Last night I figured out which screw sets this preload and adjusted the spring tension by advancing the set screw ¼ turn. I need to borrow the accelerometer again, but I’m definitely getting better performance in the 2000-3000 rpm range. My boost numbers are also higher in this range (they’re now about 15 psi where before they were between 14 and 14.5 psi). EGT’s were very low but it was more likely due to not holding full fueling conditions very long.

 

Flow through an orifice is not a linear relationship to pressure, if I remember correctly. I think it is proportional to the square root of pressure. Compressible flow is even different as it will max out at the speed of sound.
Here's a good derivation of flow rate from the Bernoulli equation:
http://www.pipeflowcalculations.com/orifice/theory.htm

Anyway, it’s better if you don’t have to change injectors. That's a neat design of that Bosch pump. You have to be impressed at how far diesels came on mechanical pumps. I'd like to see it torn down with an explanation of the low-speed torque control. The amount injected per cycle must be based on pedal position and speed, instead of just pedal position.

I'm very curious to see what tuning is available if I can get a common rail Cummins. I know that their emissions, cold starting, and sound control strategy is centered around creative injection schemes.

I don't have an answer yet to your engine theory question, where you see higher MPGs when blocking off the intercooler during cold weather. I'll have to dig out the schoolbooks! Perhaps Dr. Kittelson will have time for a question from an old forgetful student. He knows pretty much everything about diesel theory, as far as I can tell.

Off the top of my head, I would say that it doesn't make sense. The Carnot efficiency increases as the temperature extremes grow further apart: E = (T1-T2)/T1. Of course, a diesel engine does not run on a perfect Carnot cycle, which assumes reversible and adiabatic processes. Have you monitored engine temp? Are the reduced MPGs happening only when the engine is below optimum operating temp? I guess that might explain some incomplete combustion, but I don’t know enough about diesels to say whether or not that is likely in an already lean mixture. The warmer inlet air (with a blocked intercooler) should be less dense and lead to a lower operating pressure, and I would think that may actually take longer to warm up the engine. Your experiences don’t seem to reflect that. As background research I would stick thermocouples on the inlet and outlet of the intercooler and record that with MPG and whether it is blocked or not. Do you notice a significant difference in EGT when you block the intercooler?

I will consult my books this weekend to see if I just said anything completely wrong.

 

Thanks for the feedback and the link.

I thought with the electronic interface on the common rail version that the whole fuel curve can be tailored for each engine. How much tailoring (above the 110hp 305 ft-lbs max for the stock engine) you can do I'm not sure. Since they are maxing out the rail at 16,000 psi (which is quite low compared to most common rail designs) it would seem like increasing pressure would be an easy place to start (maybe fooling the pressure sensor if the electronic interface won't let it go above a measured 16,000 psi). Seems like there's a lot more room to grow with that engine since it's already starting with some pretty nice torque numbers.

Regarding the intercooler and engine efficiency at low to mid fueling conditions: After reading how the mechanical pumps try to adjust injection timing for various conditions I'm wondering if it's just a limitation of the injection pump not being able to advance the timing enough in cold conditions? By keeping the intake air warmer in the winter by blocking the intercooler the increased efficiency due to a better optimized start of injection may be more important than the cooler intake air?

 

I suppose you could drill holls in your flywheel to bolt up to the rear of the engine but this will affect your clutch surface/flywheel interface. You have to make sure the distance between your trans and the flywheel are appropriate to ensure the clutch will engage the flywheel, the transmission shaft will engage some type of pilot bearing in the center of the flywheel, etc.




yes i had planed on addressing clutch and input shaft depth concerns.

thanks for all great info!!

 

Well, I was incorrect about the governor. Turns out the increase in boost was due to the switch from winter to summer fuel and not doing anything to the governor. After reading ALL of the Bosch manual I realized all I was doing was adjusting the mechanical shutoff device. What a newbie mistake.

I've been reading the first gen archives and seeing what they have done to their VE pumps with the 3200 rpm governor spring seems to be what I would need to do to the VE pump on this engine. The tag on my pump has the following description: NP-VE 4/11F1300RNP2489.

From what I've read this refers to a 1300 rpm governor (2600 engine rpm) governor spring. This must be why the engine hp stops increasing at ~2600 rpm even though I increased the max rpm screw setting. Seems the 1st gen guys discovered this a long time ago . . .

May have to spend some more time in the 1st gen forums.

 

TDIwyse -
I will eventually get around to some more of your engine theory questions.

You stated that you feel that your B3.3T lets you do anything that your 4.0 did before. You are then entirely satisfied with your Jeep's ability to merge into traffic and maintain highway speeds?

I am certain that the engine (either the B3.3T or the QSB3.3) is the one for me, as I have been driving the 2.5L Wrangler since '98. I think that it has sufficient in-town performance but suffers on the freeway with hills and headwinds. I attribute this to poor torque and low revs. Basically the 2.5 and QSB3.3 have similar power ratings, but the 2.5 must spin near 5000rpm to achieve it. I don't have a curve for the QSB3.3, but if it is anything like yours, it makes good power at ~2000 and great torque at ~1500.

In looking for a worthy recipient I'm considering the '04-06 Unlimited Wranglers. I think that once I can get good highway mileage I might like to take it out of town, and in that case the extra wheelbase will be nice on the freeway. I also want to run 31-32" tires. I'm afraid that if I get too carried away I will have a vehicle too heavy for peppy driving with the diesel.

The stock 2.5 with a softop is around 3400 lbs with an operator, giving me about 28 lbs per hp. I figure my tires and hardtop add 200 more. The unlimited would add another 200, and the engine would add another. I'm looking at 4000 pounds going down the road, giving about 36 lb per hp (assuming the stock 110hp Cummins). Compare this with the Viper and Z06 (around 7 lb per hp) or a Ford F250 crewcab diesel (around 21 lb per hp). Theoretically then it would be considerably slower than an empty diesel 3/4ton. Of course this doesn't consider axle ratios, rpms, etc.

On a qualitative basis, how do you feel your Jeep performs relative to other vehicles? I have driven all 3 diesel pickups and would be entirely satisfied with matching that performance.

 

here is some links to cumins i found concerning B3.3 and QSB3.3.
the QSB series usually is in the "stage 3 tier 3" under construction or agriculture if you look under applications. there is some curve charts
there too.
there also seems to be a difference which site you look at for cummins;
this is the main site:

http://www.everytime.cummins.com/every/everytime.jsp

other sights southern plains i found more info:

http://www.cummins-sp.com/engines/index.htm



here is a link to QSB3.3 power curves and other info

http://www.everytime.cummins.com/every/pdf/4087118.pdf

 

Yes there is lots of good info in the 1st gen forums to get that ve pump putting out more fuel. You should be able to get enough fueling with just some turning of screws that you'll need more air.

 

BEST YET

http://www.everytime.cummins.com/every/pdf/4087038.pdf


BY THE WAY I WAS TALKING TO THE SOUTHERN PLAINS LOCAL REP.
AND THEY ARE NOT ALLOWED TO SHIP OUT OF THE AREA BUT HE DID HELP ME FIND A LOCAL REP.

HOPE SOME OF THIS WAS HELP FULL