Builds Family haulin' (3 Viewers)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Thanks for the response. My tendency to tinker has been spread out over several vehicles. I am realizing how much time it takes to do things while being a Family guy/ Dad/ Husband/ employee etc. Sometimes things are sacrificed that shouldn't be in my situation. Keep up the good work.
I have a lot of time invested in my diesel swap and watching your progress is encouraging/motivating.
 
The MBC is the manual boost controller I have installed in the boost reference line going to the AFC. With almost 3 times the boost the AFC was designed for it goes to full fuel rather quickly and with big sticks it gets smokey so this helps delay the fueling. I could probably go with a stiffer spring inside the AFC and achieve the same thing but having the MBC outside of the AFC makes it more convenient to adjust.
 
Ah, gotcha. Forgot you had something in the AFC reference line. Thanks for clarifying :cheers:
 
Even though we have had limited actual wheeling time together we have shared some time in the shop and I've really enjoyed watching Dora "grow up" over the years. You really do have a sweet 60. Hopefully we can share some trail time soon.
 
brokenparts said:
Even though we have had limited actual wheeling time together we have shared some time in the shop and I've really enjoyed watching Dora "grow up" over the years. You really do have a sweet 60. Hopefully we can share some trail time soon.
Click to expand...

Thanks, welcome back the the landcruiser world and I look forward to more trail time. I did see that link and it looks like there might be a little more shop time coming up. Interested to hear about the plans for the new rig.
 
As I continue tuning I continue to have exhaust hazing issues that I don't like. I've been doing more reading on injector options now available as well. I've contacted a couple of injector shops asking questions and I'm going to pull my 5x14s and bring in my stockers to see what the pop pressures are set at on all of them at a local shop.

Perhaps the issue lies in the 5x14s having too low of a pop pressure. They are suppose to pop at 245 bar but I'm curious if they actually are and if there would be any benefit of a larger injector popping off at a little higher pressure like at 255 or 260 bar. They could adjust them to what I want. Potentially higher pop pressure could atomize the fuel better but I'd need to run more timing to accommodate that. Might not be more than I'm currently testing at. Then there's the potential added stress on the Injection Pump to build more pressure for the injectors. I now have plenty of fuel supply so that part won't be and issue so I won't starve the IP.

I'm bringing in my stock set because he said he wouldn't charge anything to just see what they are popping off at. If there are additional problems then I'm either looking at setting up new injectors or just new nozzles and get the set balanced between each other. If I go with new nozzles I'm leaning towards a max size of 5x12 and probably a SAC tip or an injector in the 50-100hp range. Dynomite Diesel is just a state away and was nice to talk to over the phone. CPP, DPI and DAP all sell some interesting options too. The buzz word seems to be extrude honing/polishing the holes to create a better flowing nozzle. I believe my local shop offers that service.


On a related tangent on spray patterns (I don't know if I ever documented this) I've determined the rebuild kit I used years ago had 155 degree bowls. I ordered my injectors that way but the part number listed on the top of the replacement pistons is for a 4BT/6BT application. That means:

4 or 6 = number of cylinders
B = series
T = turbo'd
A = aftercooler - water
A = aftercooler - air to air

It was for a B series Turbo Non-Intercooled. As a basic classification (6BT info found) 155 bowls/injectors came in the Non-Intercooled versions and the 145 bowls/injectors came in the Intercooled version. While my original components (4BTAA) were for an intercooled piston version my rebuild kit replaced it with a non-intercooled piston version. A little confusing but clear as mud.

While it's best to run matched angles one can get away with mismatched spray angle to piston bowl if it's compensated for by playing with the injector tip position in the bowl and the timing.

145 injector in a 155 bowl will need thicker injector washers and more timing.
155 injector in a 145 bowl will need thinner injector washers and less timing.
 
Last edited:
You don't have your own hydraulic jack based pop-tester? I've thought about putting one of these together but not a huge priority..

I nominate you for an honorary MUD-U Doctorate of Diesel!
 
I've thought about building a pop tester but I'm hoping I can get them dialed in with this local shop instead. We'll see how it goes.

There are certainly plenty that know more than me but thanks for the vote.
 
I don't know man, I still think your 5x14s are too big, which would be the cause of your hazing/excess smoke. Based on some calcs on 4BTSwaps state that stock 105hp (engine rating) injectors flow enough fuel for roughly 300hp.

Assuming (and I think this is true based on my reading on quickserve) that the 4BT (non intercooled/aftercooled) injectors are the same as the 1st gen RAM non-intercooled cummins injectors, then your nozzle surface area is huge by comparison:

http://www.1stgen.org/viewtopic.php?t=1363

4x.013 = .000531 (what I believe to be stock 4BT injectors)
5x.014 = .000769

That's quite a difference.

http://www.cumminsforum.com/forum/94-98-performance/188404-injector-chart.html
http://www.dieseltruckresource.com/forums/1st-gen-ram-all-topics-93/injector-size-chart-240746/
 
Last edited:
Funny, I've got that same link with the injector chart open on another tab. The stock sticks I pulled out of my engine were 5 hole so that has me curious what size they really were. Perhaps the local shop can shed some light when I stop by tomorrow.
 
The stock ones were 5 hole? s***, there goes my theory.

Wait a second, yours was aftercooled, right? What's your CPL again? 120hp rating?
 
Yes 120hp rating, aftercooled/intercooled air to air. I don't have my CPL committed to memory so I'll have to get back to you on that.

I tried logging in to the quickserve database previously to look up the piston part numbers but I've forgotten my credentials. I may have to set up a new profile since the reset email didn't come back to me.

Of course the original stock injectors could have been 4x13s and someone in the past changed the injectors I'm calling stock with the 5 holes I pulled out.
 
Ok so I started reading this thread on Sunday(just your posts Boots) and just finally finished.....damn! You are a inspiration to us all man! I usually give up after something fails but now I have a reason to keep going!! Keep up the great work and I can't wait to see what you have next to do! (Coilovers.....;)) subscribed!
 
Last edited:
That makes sense then. I've focused my research on my motor, which was non-intercooled. It's totally possible that the 4BT injectors changed with the 6BT injector HP ratings, so 5 hole nozzles would make sense.

Maybe 5x.014s aren't that much bigger than what you had! Either way, they're large.
 
GLTHFJ60 said:
Either way, they're large.
Click to expand...

Yes, agreed. I decided to trust the recommendation from builder at the time as he suggested the bigger size for more potential to grow into. I think he had more experience with the 6bt rather than the 4bt. Might have to chock it up as education funding if they are just too big. I pulled them last night from the motor and after having studied SAC vs VCO more recently these 5x14s have SAC nozzles. My stockers are VCO nozzles. Also #4 had more soot build up on it than the others. I'm going to see if I can leave a little early today so I have plenty of time at the injector shop to test and discuss options.
 
Keep us posted!! Diesel injectors are a science all their own.

EDIT:
As another reference, one of the 4BTSwaps guys gave me this site, which appears pretty cheap. The referrer says that the injectors he purchased from here have served him well:

http://oregonfuelinjection.com/index.php?pid=32
 
Yes, OFI is 2 hours south from me. I did consider them as well. I wasn't sure how much of the performance side they were into but I never called to really find out either. They do have good prices.
 
Warning, This is a long post.

Interesting results from the pop test. I went to Diesel Fuel Injection Service locally to get all my injectors pop tested. They were nice and took care of it while I waited and didn't charge me anything. While I was waiting I asked them a few questions and it quickly became apparent that this was not a performance oriented shop. Great guys and willing to do whatever I wanted but they steered away from suggesting any directions related to performance. I would need to know exactly what I wanted before hand but they did offer extrude honing (that they outsourced) in three levels: Phase 1 ~ 40hp, phase II ~ 60 hp, phase III ~ 90hp. So here are my pop results.

Stock set (should be 245 Bar)
1 - 225 Bar
2 - 234 Bar
3 - 240 Bar
4 - 236 Bar

Modified set (tech estimated they were probably set to 260 Bar)
1 - 255 Bar
2 - 248 Bar
3 - 242 Bar
4 - 237 Bar

The tech noted that all the injectors were still giving a good spray pattern and are usable. This somewhat surprised me as I thought my stockers were on their way out. I asked about spray angle and they said they'd need to take the injector apart to get to the numbers listed on the nozzle to find out. The wide variation in pop pressures has me concerned but it wasn't enough information to make a decision so I told him I'd like to do more research (since they didn't really offer any new ideas) and think it over before doing anything.

The theory I was trying to support was that the pop pressures being too low/too different from each other is causing hazing/smoke. I found a suggestion that a ~20 Bar difference equates to 1 degree retarded timing. What I'm not sure about is if one degree difference between injectors would cause that kind of haze.

I decided to try out the stock injectors. Pop pressure is tuned by shimming the internal injector spring, more preload/shims = higher pop pressure. I didn't want to pay ($28 per injector) to get the stock set reset but I did want to bring Stock-1 up closer to the others. I took apart Stock-1 and Modified-1 to see what my shim options were. I ended up adding .015" in shim thickness to Stock-1 as a guess to bring up the pop pressure on Stock-1. While I had Stock-1 and Modified-1 apart I took a look at the nozzles for numbers. Modified-1 did not have any numbering so I figure it was a blank nozzle that was modified to what it is now. Stock-1 did have writing on it.

DSLA 155 P278 66521 is what I found and the only information I found through searching is that this is a 5 x .012", 155 degree spray angle VCO or Sac-less injector that looks like maybe a marine 370. What's very interesting is that it is a 155 degree pattern. That makes me wonder what the pistons were in my engine before I rebuilt it. Conveniently they match the pistons I have in the engine now and with the tech stating the pattern is still good I just had to try them out.

I used some middle sized seal washers (~.062" thick) and installed my stock set of injectors. Tuning was off of course but after a few adjustment these injector appear to be working. Crazy, I had a decent set of injectors to power my twins all this time and didn't know it.

With the engine cold they haze at idle like any other injector; however, once everything was warmed up they are clean at idle no load. I shifted to drive and put on the line lock to simulate a load (as if I was at a stop sign in drive with the brakes on) and with it idling there was no haze. I had a chance to follow my wife with her driving the truck and cold it hazes as expected but once warmed up it is much cleaner than before. I drove it to work today and could not see a trail in the headlights behind me like with the Modified injectors. I'm currently seeing 40psi max for total boost. I did turn in the power screw 1/4 turn in more than I've ever had it with the fuel pin at only 50%. I'm at 18 degrees timing and may bump that down one degree to see what it does. Comparing the two injector sets (I know it's not really apples to apples) the stock set seems to run a little smoother and the power delivery is smoother. The Modified's felt more powerful at the same pump settings but tuning will probably make up for that. It's still possible that I needed to run more timing for the Modified set to help clean them up but I'm afraid drivability might start to suffer with the timing they might have needed.

At this point I will continue tuning the stock/original set and probably look into a fuel pin. If that gets me where I want I'll have this set reset for pop pressure and enjoy.
 
Last edited:
You must log in or register to reply here.

Users who are viewing this thread

Total: 4 (members: 0, guests: 4)

Share this page

Back
Top Bottom