Engine/Transmission (1998.5 - 2002) Banjo Bolts

[Billy Diesel]

Has anyone adapted the stock schrader test port to the over-sized banjo bolts found at Geno's, etc. ? I want to install all the bolts, but due to my pressure dropping to 3 psi at WOT, I still need to be able to have the dealer check the pressure. Or do most people just swap the bolts before heading back to DC?



I have checked at the local parts stores and local Cummins supply store, but no luck.



TIA

 

[JBHale]

Try rod at wildcat diesel.com, he has the schrader's in stock.

 

[krs]

It's a small thing to drill out the fuel passages in any banjo bolt including the one with the Schrader valve.

I don't remember the exact numbers but the banjos sold by Geno's are about . 050" over the OEM ones. Don't go so big that you weaken the bolt

 

[Diesel Gunner]

Ditto what KRS said. Take your OEM's and drill them out, de-bur, and make sure that they are clean. Be careful reinstalling. It is even more critical now since material has been removed.

 

[rweis]

BE CAREFUL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



I almost twisted off a drilled banjo in the lp. LUCKLY I got it out. HATE to think what the feeling would have been if it would have been in the VP.



Reason I changed course and went the way I did (see sig). One screwed up lp pays for all the new lines. One screwed up VP pays for a LOT of BOMB'ing.



Bob Weis

 

[illflem]

Are you guys sure that reamed out banjo bolts help anything?

We were doing some line restriction calculations over in the products forum and it seems as though the OEM fuel filter is the limiting factor in fuel flow.

 

[rweis]

There were several thoughts that the fuel does 90* twist and turns was not good to the overall flow, and there was a more restrictive line somewhere in the fuel system.



I have the DC hose part of each banjo right here in my hand. Coming out of the tank feed line into the LP about 1/4 or so. Coming out of the LP to the filter is maybe 5/32. Going into the filter is maybe 5/32. Coming out of the filter is back to about 1/4 or so. Going into the VP is about 1/4 or so.



The sharp turns, concept of fluid turbulence, reduced tubing out of the LP and into the filter is why I went to Aeroquip fittings for smoothness of turns and 3/8" ID tubing for uniform ID. And to relocate the LP so it has minimum sucking and maximum pushing.



My psi drop across the filter with basically a stock engine is consistently 1psi at idle up to 60mph O/D out 5er 8k WOT.



If the restriction has to do with the filter I would think it might be the fitting that mates to the outlet side of the LP and the input side of the filter. WHY DC did not keep a uniform ID I have NO idea.



I understand the filter flows 75 GPH (I have not tested that). One question is what does the VP require to cool itself and feed the injectors based on different levels of fueling from stock to heavy bombing.



example: What does the Edge Comp on level 3/5 with DD3's and a PDRHX40 require at idle?, then pulling different weights at different speeds.



What I am going to do is watch the psi on the VP side of the filter. If psi is higher significantly on the LP side and lower by say 5psi on the VP side and the filter is clean, then the filter can't pass the required amount of fuel and figure something out then.



Bob Weis

 

[illflem]

Bob, from what I understand it is the filter media itself that limits the flow to 75 gph. The LP is capable of 450 gph, the fuel lines can handle 450 gph but with a 7. 5 psi pressure loss.

I haven't engineered any vehicle fuel systems (hope DC did but wonder) but have done many irrigation systems. If you have a 450 gpm pump with a 75 gpm restriction in the line you either get rid of the restriction or use a smaller pump since the large pump is working harder than need be to overcome the restriction and either kills itself or uses too much power.

 

[rweis]

Well then, there are several other filter choices out there. I would think there is zero sense puting a 75gpm limit in the line, but DC probably did just that.



What do you think are other choices?



What are the needed characteristics?

Filter to xx microns.

Water seperator with a sensor? maybe without a sensor?

Fuel heater?

What flow rate?



There are several well known manufacturers that do this on a regular basis RAYCOR comes to mind, I think probably 3 or more.



I filter my automatic fluid through a "weis version (meaning VERY heavy duty)" hydraulic filter. Same system might filter diesel as well. It is for a LARGE hydraulic system, I think 15 gpm maybe more at 10 microns up to 300psi, 250*F. Would make a heck of a fuel filter, but no heating or water seperator.



What's on your mind for specs?



Bob Weis