Stock Fuel Setting.

[Dougal]

While I'm having a whole lot of fun with my engine the way it is, I'd like to find out how far away I am from stock fuel settings.

Can someone who has stock fuel pump settings measure the protrusion of the fuel screw from it's mounting tap to the end against the cam?
I know it's not a completely accurate way, but it'll give me some idea.

Three years ago I advanced the fuel screw by 1/4 turn. Recently I wound it back in (see the "It's Alive" thread) to what I thought was stock levels.
But I'm having to run 19psi boost (not intercooled) to keep my EGT's below 750 deg C. While it's fun, I live in fear that my wife or someone else might keep their foot down and melt something.

And with no intercooler, 19psi with a 65% efficient turbo compressor gives theoretical intake temps of 225 deg C.

[Bush65]

My engine is in a bad position at the moment. I can measure tomorrow afternoon (have to go out early). But it is a different pump to yours.

[Dougal]

My engine is in a bad position at the moment. I can measure tomorrow afternoon (have to go out early). But it is a different pump to yours.

Much appreciated if you can.

[Blknight.aus]

reading emei on pump rebuild which of the myrad of adjustments did you want to know about?

the external control arm limit adjusters (on the top where the throttle cable hooks in)

the full load setting bolt (which is responsable for the absolute maximum travel of the rack)

The idle speed setting (dont think so but its there)

or the torque cam control rod adjustment?

Doing these properly requires a test jig BUT you can do them by touchy feely with the pump on the engine. (I dont advise this)

[Bush65]

15.75 mm - measured from the face that is also the joint for the governor housing cover, to the end of the full load screw, that contacts the cam.

[Dougal]

15.75 mm - measured from the face that is also the joint for the governor housing cover, to the end of the full load screw, that contacts the cam.

Thanks.

A quick measure gets about 17mm, but I'm avoiding hot parts in the engine bay to do that.
Of course as you said different fuel pumps, but maybe there is equivalence between those for setting maximum rack travel.


the full load setting bolt (which is responsable for the absolute maximum travel of the rack)
That's the one.

[Blknight.aus]

ok the full load bolt is an adjustment that requires the pump being in a proper jig to test and adjust... however theres nothing wrong with doing about 1/8th of a turn and relying on your EGR and smoke output to adjust it...

as I recal you have the turbo version so if you have the boost compensator dont forget that when your adjusting it you need to apply air pressure to that to clear it from the rack or your not going to get a clean adjustment.

[Dougal]

ok the full load bolt is an adjustment that requires the pump being in a proper jig to test and adjust... however theres nothing wrong with doing about 1/8th of a turn and relying on your EGR and smoke output to adjust it...

as I recal you have the turbo version so if you have the boost compensator dont forget that when your adjusting it you need to apply air pressure to that to clear it from the rack or your not going to get a clean adjustment.

Yeah short of pulling the pump and measuring the fuel output, I figured measuring the screw protrusion will give me some idea. But protruding 1mm more than John's one would mean that mine should have less rack travel, so the method ain't that great.

The Aneroid on mine has an internal pushrod which internally does exactly the same job as lengthening the external screw length when there's no boost.
Fixing and adjusting the aneroid has changed my engines behaviour completely.:)

It's also changed my driving style.:twisted:

[Blknight.aus]

Yeah short of pulling the pump and measuring the fuel output, I figured measuring the screw protrusion will give me some idea. But protruding 1mm more than John's one would mean that mine should have less rack travel, so the method ain't that great.



Actually measuring the output isnt what your after there your after the physical position of the rack internally on the pump.


the stupid simple version of how to adjust that pump is...


1. set the stop position then ensure all pumps do 0 output

2 set idle position and ensure all pumps have the same output

3. set rack at max travel and recheck

4. adjust max governed position and pump output

5. adjust fuel out put on running rig for full load setting

6. recheck shut down fuel output is 0

7. adjust the travel stops on the top of the pump

8. run up on test rig and confirm fuel output at starting condition, idle, full rpm (no load) full rpm (full load) and shut down positions.

Not quite by the book but thats about the order that you do all the adjustments.

If you want to be a dumb yokel about it, generically speaking, its possable to set that pump up for full fuel output with the rack in the stop position and then it will try to give you more when you get on the noise....

Measuring the screw lengths isnt going to do anything for you as there are no fewer than 4 components in the pump that have quite a large manufacturing tolerance that are going to influence the position of the screw.

[Dougal]

Actually measuring the output isnt what your after there your after the physical position of the rack internally on the pump.

Yes, but having just put the whole thing back together, there's a limit to what I'll pull apart again just for curiousity.

The spare pump I have at home measures 16mm, that's very close to Bush65's measurement, but the one I'm running is quite different in many internal details. I tried a few months back swapping that spare pump (it was rebuilt recently) onto my engine, but the drive gear has a different bore size. I found that after swapping enough internal parts to change the aneroid across.





the stupid simple version of how to adjust that pump is...


1. set the stop position then ensure all pumps do 0 output

2 set idle position and ensure all pumps have the same output

3. set rack at max travel and recheck

4. adjust max governed position and pump output

5. adjust fuel out put on running rig for full load setting

6. recheck shut down fuel output is 0

7. adjust the travel stops on the top of the pump

8. run up on test rig and confirm fuel output at starting condition, idle, full rpm (no load) full rpm (full load) and shut down positions.


Thanks, but I'm lacking both the test rig and the motivation to pull the pump off the engine.

But while I've got your attention, what power do you think this pump is capable of supplying? Bush65 and me had a few discussions on 4BTswaps.com regarding it, my conclusion was maybe 150kw based on BSFC of about 250g/kwh.

[Blknight.aus]

thats a very curly question as that pump can have a lot of different internals fitted to it to make it do different jobs...

its theoretically if pushed to the absolute limit by parts swapping between the varients to get a setup that will pump as much fuel as possable. We discussed this a lot in the dieso room at ALTC and I think from memory we came up with a max fuel of nearly 450ml per pot per 1000 deliveries. I have no idea how to squeeze that much air into the chambers to effectively burn that much fuel very very rough guestimations worked it out at each pot would need nearly 20l of air inside it prior to the upstroke on compression, Thats a very very big and very very angry turbocharger or supercharger.

on a stock pump its nearer the 250ml/1000 mark but in reality you almost never go past half maybe 3/4 of that even on a worked up turbod version. the stock version has the absolute max set as something like 125ml and the governor limits it to about 95-100ml to the 1000.

you can check you pump deliveries without pulling it down and Ive been known to do it with a specially distorted injector pipe on each pot as part of a major service if low power is complained about even tho every other possable source has been investigated.

ive also been known to install injectors upside down to do a spray pattern test.

[Dougal]

thats a very curly question as that pump can have a lot of different internals fitted to it to make it do different jobs...

its theoretically if pushed to the absolute limit by parts swapping between the varients to get a setup that will pump as much fuel as possable. We discussed this a lot in the dieso room at ALTC and I think from memory we came up with a max fuel of nearly 450ml per pot per 1000 deliveries. I have no idea how to squeeze that much air into the chambers to effectively burn that much fuel very very rough guestimations worked it out at each pot would need nearly 20l of air inside it prior to the upstroke on compression, Thats a very very big and very very angry turbocharger or supercharger.

on a stock pump its nearer the 250ml/1000 mark but in reality you almost never go past half maybe 3/4 of that even on a worked up turbod version. the stock version has the absolute max set as something like 125ml and the governor limits it to about 95-100ml to the 1000.

you can check you pump deliveries without pulling it down and Ive been known to do it with a specially distorted injector pipe on each pot as part of a major service if low power is complained about even tho every other possable source has been investigated.

ive also been known to install injectors upside down to do a spray pattern test.

Have a dig through this thread.
http://www.4btswaps.com/forum/showthread.php't=1035

The figure John found was 120cc per thousand strokes. That's what I took and with the 250g/kwh BSFC came up with 550Nm of torque.
If we can get 550Nm at 2600rpm then there's our 150kw.
Iveco make a 3.9L diesel with 550Nm of torque, it runs 1.6 bar boost with a max intake temp of 50 deg C.
I figure without common rail we'll need close to 30psi to burn clean.

[Blknight.aus]

thats about what you can get out of it without being deliberaltey nasty to it and setting it WAY out of design specs..

when i get chance I'll see if i can find my calculated air fuel ratios chart that has look up tables for what your doing