The pics of the injector is now on the photo link (the first post in this thread has the link).

 

Got my nozzles back from Extrude Hone and had the local Bosch shop put them back on the injector bodies and check the balance on the new injector bodies. They were all very closely balanced so no need to adjust them. The spray patterns looked excellent.

I've added photos that show some of the details of the injector swap. This was my first time swapping injectors and found the writeup at the TDIclub (http://pics.tdiclub.com/pdf/injector_install_howto.pdf) written by Davin Swanson to be extremely helpful. I spent about 3 hrs doing this.

There was some flaky carbon buildup on the injector nozzles (can see some of that on pic DSC00796) that wipped off with just a brushing of a rag. The injector tips after brushing with a rag are shown in pic DSC00797. I was glad to see that a year and 13,000 mls of running very high concentrations of biodiesel hadn't led to any excess carbon buildup on the tips of the injectors.

After the install I remeasured hp/torque with the accelerometer. At first I wasn't measuring much of any change from the previous runs but then realized I was running on >90% biodiesel. I topped off the ~1/2 full tank with D2 and re-measured with ~B50. The difference between peak torque on B90 and B50 was about 10-15 ft-lbs and peak hp was about 5-10 hp.

The photo section also has the new hp/torque curves measured with B50 on at 83 F. I had also adjusted the max rpm setting to ~3250 rpm where the governor defuels.

The modified injectors seems to help the max hp more than the max torque. I'm flirting with 140 hp now which is about 15 hp more than I had previously measured (about 12% increase). Max torque is now ~325 ft-lbs only about 10 ft-lbs more than previously measured (about 3-4% increase).

I still have no smoke at WOT and the EGT's and boost are not much if any higher (I have small analog gauges so it's hard to tell for certain).

I'm thinking it would be safe to say that one could go more than a 15% increase in nozzle modification and still be OK in terms of boost/EGT's.

The price for the nozzle modification was $33*4. The Bosch shop which removed the nozzels from the injector bodies, re-installed the nozzels and pop tested all the injectors was $64.

 

The yahoo picture site is closing so I've moved the pictures to flickr. The new weblink for the photos is:

http://www.flickr.com/photos/10201173@N06/

I've also had two fill ups since the new nozzles were installed. The average for the these fillups which covered ~420 mls of mostly back and forth to work driving is 33.2mpg. This is an all time high for two consecutive fillups and included a single fillup all time high of 35.2 mpg (this one had some longer drives than the back and forth to work conditions).

I'm wondering if by having the injector holes larger it allows for a slight increase in injection timing? Since a given amount of fuel can be pushed through the injector nozzle in less time it would seem that for a given quantity of fuel from the injector pump it would effectively delivery this fuel into the cylinder faster, and closer to the optimum crank angle? Is this thinking correct or off-base? It would seem this improvement in effeciency would break down if the holes are so large that effective atomization of the fuel degrades and combustion efficiency starts decreasing.

Any comments on this theory?

 

TDIwyse,

I just sent you a PM this morning about the picture. You can ignore it.

Chuck

 

I've had some people PM about updates.

Still driving it as my commuter vehicle. I've now had 8 fillups with the new nozzles. Fuel was B50-B90 over these fillups. Average fuel economy has improved by a statistically significant margin.

35.2
32.0
35.0
28.1 (lots of rain and stop-n-go in town driving)
35.3
31.8
32.4
33.5

I am unable to get the EGT's above 1100 F with the modified injectors. I'm thinking the injection pump is able to get the fuel into the cylinders sooner and is effectively advancing the timing, even at full fueling conditions.

The transmission seems to be holding up to the torque, but I'm not doing any rock climbing/towing. It does leak some tranny fluid but doesn't seem to be anyworse than when I got the jeep. The transfer case output shaft area has started leaking some fluid this summer. I've heard that's a pretty common issue with the slip yoke design of the np231.

I've decided not to pursue the power steering route and will be replacing the power steering gearbox/pitman arm with a manual steering box/arm. This should improve the steering effort as the turn ratio will go from 16:1 to 20:1. Will also reduce some weight on the front end.

 

12 or 24 volt alt and starter??
vacumm pump ?? for brake boooster??
what did you use for power steeing pump??

 

were you able to use to old gas tank and pump; or did you have to modfiy them to handle the heavyer diesel fuel versus gas. after your conversion.

i am thing of doing this convertion to my v6 toyota 4x4 extra cab 1991 with 4 inch lift kit and 4 wheel disc brakes.

 

12 Volt alternator and starter.

Page 1 and 2 of the thread discuss the brake and steering stuff.

In short, I'm using a 12V electric Stainless Steele Brakes vacuum pump for the brake booster. Saves fuel since it only runs when it needs to produce vacuum.

Also, I never did go the sae pump route to get my power steering working. Decided to just convert it to manual steering (I've been using the power steering gear box without the power steering pump).

 

From page 4 of the thread

"Other things I've done in the past couple months to "dieselize" the jeep are: replaced steel fuel tank with a plastic one to minimize condensation. Added a Stanadyne Fuel Manager with 100W fuel heater and 5um fuel filter/H2O seperator elements inline with the factor fuel filter/H2O seperator. Added an electric lift pump and an inline mechanical pressure gauge. Replaced the trouble prone vacuum actuated front axle engagement motor with a mechanical Posi-Lok system.
"

The old steel tank was working fine, but I like the idea of plastic -- less risk of condensation.

Nice sounding project you're working on. Please keep me updated!

 

i have 32's that actual measure about 33 inchs tall. with 4.10 front and rear diff. i turn 2600 rpm@80 and 2500 rpm at about 67 mph

so my question is runing the b3.3t at 2500 or 2600 rpm on the freway for commuting; would that be too high of rpm?? for too long??
i usually run about 65mph on the freeway.
i saw you said on page 6 the max is 3100 or 3200 rpm before damage to motor as i recall.

i like this b3.3t it has higher tq-ft than my gas motor,v6 stock 3vz; which will allow me to run a taller gear on the freeway; due to tha fact that hp rating is more relavent in higher rpm ranges and is derived fron tq-ft-lbs

quote from page 6

The engine is really smooth above 1700 rpm. I've been cruising in 4th gear at ~2000 rpm on the 55 mph county roads (actually going 60mph at 2000 rpm in 4th gear which is a 1:1 ratio for the AX-15). It's really smooth all the way up to 2600 rpm

 

You are probably directing most of your comments and questions to TDIwyse; I can't help but chime in...public board & all

If the basic design of the b3.3 is the same at the 6bt, then no...you can run WOT all day long if you want; only your mpg will suffer.

I would consider going down in gears...3.73 or even 3.55. With the low rpm torque of the b3.3, you should be able to tolerate a lower gear for crawling & wheeling, even with the 33's. The higher (lower numerical) gears should help increase mpg as well. I know the 6bt's, ISB, and ISBe are more efficient at lower RPMs; just don't go too low as you'll be lugging the motor.

HTH

Tony

 

What he said.

The only two data points I could find for BSFC and rpm showed better efficiency at lower rpm. Also, the manual had 3250 rpm for the point where destructive harmonics start to occur.

As I recall there were some comments in the owners manual about not running at max power (which would be full fuel at max rpm) for more than a certain duty cycle (might have been something like for every hr at max power you need an hour below max power, but I can't recall off the top of my head). Think this is a pretty standard clause for industrial engines which can be forced to exert max power all day long which is almost unthinkable in an automobile (hills, stop lights, off ramps, traffic, speed limits, etc. would keep you from running at max power constantly).

I think you would be happier with a lower axle ratio. But the engine should be able to operate at 2600 rpm for extended periods without issue.

 

Keep in mind that the engine is new and will take awhile to break in.

I hope that you've broken it in properly (lots of WOT and loud pedal usage).

I'd expect that your mpg will settle in near 35mpg once it's all broken in.

Justin

 

Some taller tires would probably be cheaper than changing gear ratios.

 

Did a second oil analysis. Specifically wanted to see if the modified injectors were causing any issues. Here’s the info:

Oil Mobil 5w-40 CI4+ full synthetic oil
~4200 mls on oil (almost all of it with the modified injectors)
~ 14500 mls on engine

No oil used during this interval (or anytime that I can remember). Engine has been using synthetic oil since first oil change (which was done very early).

Wear Metals (ppm)
Al 2
Ca 2367
Cr 0
Cu 1
Fe 7
Pb 2
Mg 437
Mo 0
Ni 0
P 1132
K 4
Si 12
Na 2
Sn 0
Zn 1281

Oil Condition/Particle Count (ct/ml)
Soot 0
Oxidation 17
Nitration 7
Sulfation 18
Water Neg
Antifreeze Neg
Fuel Neg
Visc@100C 13.7

Comments
No Action Required. Wear metal analysis results are normal. Infrared analysis results are acceptable. Water/Fuel/Glycol physical tests are negative. No problems presently associated with this sample. Continue sampling at the normal interval.


I was glad to see no fuel or soot in the oil. It seems to me that the engine is doing well in the modified condition its in.

Also replaced the front steering linkage (tie rods, drag link, etc.) as the old ones were shot and rusted up so bad I couldn’t adjust them. Also put in a manual steering gear box. It’s much tighter feeling and easier to steer now. Was also able to align my steering wheel so that when the jeep is pointed straight the steering wheel is aligned correctly (that had always irritated me).