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Convert a mechanical pump to common rail electronic??

28K views 18 replies 14 participants last post by  jayblizzo 
#1 ·
This is a very unconventional Idea. I'm not in a position to do it, but maybe one of you guys will try it. The Idea behind this is to convert a mechanically controlled 4bt to a electronic common rail so the electronic "tuner boxes" can be used to dial up or down performance/fuel.........THis idea is unusual in that you will not be replacing the injector pump.......Heres the Idea:
1. Install 4 Electronic injectors.....(Maybe from a newer 6bt?? will they fit???)
2. Construct a common rail using tubing and compression fittings:
The 4 supply lines from the VE pump will T into the common rail.
The common rail will supply the 4 electronic injectors.
3. Obtain a electronic control box.(maybe from a ISB??)
4. Turn up the VE pump to ensure fuel is available if you tune it in with the
electonic control.

Issues??: All 4 lines pump their pressure into 1 common line. It may be possible for pressure from line1 to push back into line 2 etc.. I'm not sure on this. Maybe small check valves would be needed.
I beleive a ISB common rail system works with the injectors being electronic and controlling the fuel flow. I may be wrong on this.
IF this works you could do it with a 6bt as well, or for that matter almost any diesel engine.

This is a unusual Idea. If someone does it and it works then someone will be able to make a common rail kit and make a ton of money selling it. Lots of guys like the idea of dashboard tuner box contol more than fixed mechanical tuning........If it works out, give me a little credit on the idea.
Rob Slater
 
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#2 ·
I say why ruin a good thing... Personally the maechanical system is way better, you dont need to worry about ecm, electronic injectors etc. With basic tools you can have the engine running. Now if you want to tinker and try and max out hp or something like that then fine but the mechanical system works beautiful and I think will out last any electronic version 10 to 1.
 
#3 ·
franks71vw, I agree.

All I wanna say is WHY????!?!?!

I guess I'm just to Ol' Skool!

When I want to adjust power output I just reach in the ol' tool box and get a wrench and a screwdriver:eek:
 
#6 ·
common rail conversion

now I do not pretend to know my arse from a hole in the ground, as i do not own and have never owned a diesel. but if i remember correctly the reason common rail is better for economy and power (if not simplicity and ease) is because of better atomization of the fuel due to increased fuel line pressures. for example(and a bad example at that) i thought i heard someone here say the pop off pressure is around 4 thousand psi for these engines injectors, but my readings into common rail systems seem to say that the pressures are up into the 20-30 thousand psi range.

If however if i am wrong (and there is a good chance please ignore my previous ramblings
 
#7 ·
now I do not pretend to know my arse from a hole in the ground, as i do not own and have never owned a diesel. but if i remember correctly the reason common rail is better for economy and power (if not simplicity and ease) is because of better atomization of the fuel due to increased fuel line pressures. for example(and a bad example at that) i thought i heard someone here say the pop off pressure is around 4 thousand psi for these engines injectors, but my readings into common rail systems seem to say that the pressures are up into the 20-30 thousand psi range.

If however if i am wrong (and there is a good chance please ignore my previous ramblings
IIRC, you've got it right. The VE pump won't make that kind of pressure.

The other nice thing about commonrail is being able to do multiple injection events per power stroke. Helps keep the noise down.
 
#12 ·
... i thought i heard someone here say the pop off pressure is around 4 thousand psi for these engines injectors, but my readings into common rail systems seem to say that the pressures are up into the 20-30 thousand psi range.
...
IMHO, we can not predict what the pressure in the proposed common rail would be, based upon the pop pressure of mechanical injectors that are no longer present.

In the proposed common rail system, because fluids like diesel are incompressible, a pressure relief valve would be necessary to prevent the rail pressure from reaching too high a pressure. If not, something is going to fail from over pressure.
 
#9 ·
The mechanical wont make near the pressure required for this idea to work. I have already looked into doing it myself. I ifigured it would be neat to have a 4BT common rail engine. The common rail engine usually operates around 23k -26k psi and I think the injectors are seated differently anyways. Way too much work to make it happen plus you would have to have a custom controller to make it work because the electronics arent just in the injectors but the cp3 injection pump as well.
 
#10 · (Edited)
pistons must match the spray pattern of the injectors.

Next Common rail injectors fit a 4 valve per cylinder head so a VP44 head can be used kind of. there are different water passages and HG dont entirely match up on the dodge 24v vs the 03+ common rails so my guess is you have some machine work but the injectors fit intot eh same holes and seat up similarly. 21k-26k (26k being th MAX) that 03-07 common rail injectors can take. the 07+ 6.7 common rail injectors are bigger and are stainless steel so they are tough but the voltage for the selenoids on the injecotors is way different

you need the front timing cover and gear set from a 6b with common rail injection as well as the belt drive system.

thats the early tid bits then you get into electronics.. :idea:

the better atomization of fuel is a benefit of commonraila nd the pressure but the earlier model engines are more effiecient due to cam timing and injector angles piston bowls ect in their relm. going for mass hp and clean burning common rail maybe king if oyu can dial it in.


Get out the milling machine
 
#14 ·
Saw a computer controlled 4BT today. At first glance, I thought it was an ISB, but no way. It wasn't common rail. but the injection pump had no mechanical linkage. It was an industrial application on a coring drill, and the throttle was completely variable. Meant to get get a CPL# off of it, but got sidetracked doing my damn job. Had some sort of Bosch drive by wire version of what looked like a VE pump.
 
#16 · (Edited)
They do build these!

We run various cummins engines on our core drills. Just recently we were replacing a tired old deutz for a 4bt3.3. We had the option of an electronic 'fly by wire' or a mechanical (only because it was replacing a pre-emissions engine, damn EPA BS!). The fly by wire was HPCR, whereas the one we purchased was a mechanical VE

It appears that they ditched the 3.9 for tier3 emissions(and just went with what looks like a CC VE pump), but ill bet you could make the 3.3s HPCR gear work on a 3.9
 
#15 ·
The only problem I see with these electronic engines is that they are really not programable. I guess if you want to leave it stock they would be great but whats the fun in that. :D
 
#17 ·
Japanese 4 cylinder diesels are full of computer controlled VE pumps and they all seem to be the same.
The best upshot of that is that one electrical magic box can be used to up the fuelling on almost any of those engines.

Four wires to splice apparently, I haven't done it but will do eventually when I turbo my work car.
 
#18 ·
I've seen one too, It is 3.9L with a computer on the driver side of the block. Model-ISB 145, Family-ICEXHO239BAD or 1CEXHO239BAD, I can't read my notes. Date of mfg 05/21/01. It came out of a freightliner MT-35 walk-in van. It has a one piece valve cover(not 12 valve style, I have never seen a 24 valve, or common rail) It is drive by wire. If anybody knows about this engine please let me know.
 
#19 · (Edited)
VW

Couldn't you use one of the injection pumps off of a vw tdi. I read that they were just another version of the bosch ve. Also if that was the case would there be a way to swap over the electronics from a 1.9td from a jetta or beatle or passat or something. It would be cool if you could swap it all onto the 4bt. Food for thought on what seems to be a dead subject. Sorry to bring it back up.

Edit:

Also, if you had to match injector spray patterns to the piston or something (i'm a diesel nub so bear with me) could you just use the vw injector and an adapter to the 4bt's nozzle?
 
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