Jeep Cummins Conversion

clean and nice

This 3.3 Cummins will give my Jeep around 30 MPG on Diesel. This is a 100% improvement over the Factory 4.0L Gas Engine! Besides the MANIFOLD reduction in Emissions. I have around 40 Pages of information stored and it is impossible to offer all of them here. ;-) But I will try to give you the quint essence here on our web page to encourage you to convert your car and to prove it is possible!

........................B3.3T.......................................4.0L
Advertised HP....85 (63kW) @ 2600..............190 (142kW)@ 4600
Peak Torque......215ft-lbf (291NM)@ 1600.....225ft-lbf (305NM)@ 3200..
Length (inch)....28.1.................
Width (inch)......21.9.................
Height (inch).....31.4.................
Weight (dry).....515 lbs...............................     553 lbs
MpG           ......... 30 ...............................          14
# of cylinders.... 4   ....................................               6

PSI ............... 50 idle, 80-85 cruise, 135!! cold start

B3.3T Installed

The only BSFC #’s I could find were for 1600rpm and 2600 rpm. 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.

http://www.arb.ca.gov/diesel/documents/EPAshort.htm

way shorter than the 3.9

Coincidentally, achieving higher fuel efficiency also results in reduced CO2 greenhouse gas emissions from the engine. :-) Getting 30-32 mpg on mixed driving with B50-B80.

I found this link where California measured the NOx and PM emissions of various engines. They tested the B3.3 (not the B3.3T), it's down towards the bottom. NOx and PM were .128 g/kw-hr and .13 g/kw-hr. This is .095 g/hp-hr and .097 g/hp-hr. I would assume the B3.3T may be a bit higher but I can't find any data. However, as you will see there's lots of margin for error before getting in emissions trouble . . .

If you would assume traveling at 60 mph needs ~40 hp this would work out to 0.00633 g/ml NOx and 0.0067g/ml PM.

This link gives emission standards from Tier I to Tier II

http://www.dieselnet.com/standards/us/ld.php

Tier I reguirements were in effect up to ~1997. NOx emission limits were ~ 1g/ml and PM were ~0.1g/ml for Tier I. The B3.3 seems to be substantially below these limits. In fact it appears it would meet Tier II bin II emissions which is cleaner than a VW TDI.

As a reference on page 14 of this study http://www.epa.gov/ttn/chief/old/ap4..._ch02_1996.pdf shows a nice curve of what happens to NOx and BSFC as timing is retarded from about 14 to 8 deg BTDC on a Cat off highway engine. Retarding does reduce NOx but causes a large BSFC hit.

Emissions Technology

Cummins has extended EPA Tier 4 Interim emissions compliance across the product range below 75 hp. This includes B3.3 engines utilizing advanced in-cylinder combustion without the need for after treatment. Cummins approves biodiesel B20 blends for use in its 2002 and later emissions-compliant engines

Emission Standards
• Designed to meet Tier 2 emissions requirements
• Fuel injection and air-handling systems improves combustion efficiency, reduces emissions and provides better fuel economy.