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Discussion Starter #1 (Edited by Moderator)
This is a spin off of TD's thread "Feeding the Beast" http://www.dieselplace.com/forum/showthread.php?t=42291&highlight=feeding+the+beast

I've not put thought of my own into this until TD mentioned it in his earlier thread, so being I appear to be the only one running a 92mm IP i thought it fair to feed it properly too.

I approached this pretty much the same as TD outlined with his thread with just a couple of small changes but we're both feeding the beast with 1/4" fuel supply rather than 1/8". I will be adding more fittings, adapters & fuel gauges in the near future. Here's a few pics of what i've done. The main differences is the outlet on the filter housing and the inlet on the IP itself. Sorry if i've missed a few important pics but i kinda forgot to snap some shots when i got busy doing stuff.

Some idiot ran into the garage while i was having supper and started to have fun with some green paint while i was away, oh well i guess it'll have to stay now.
 

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Discussion Starter #2
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Discussion Starter #4
Yes i've been wondering about what i'm gonna do down there myself, with the 6" lift i now have room to do pretty much anything.

I'll be hooking up a gauge today and see what i get for fuel pressures.
 

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Good work CR, Heath sells a direct replacement HO pump no plumbing changes from OEM, also been looking at Kennedy's HO kit with new power relay, whatever repacement you decide to go with it needs to be a flow on fail design; that will allow IP to pull even if pump isn't running.

Or run the OEM in parallel with the replacement, if running 2 different capacity pumps in parallel you'll want a check valve to keep the HO pump from back flowing thru the low output one. I'm thinking for the Cummins one I'll get one of those pressure switches Dan Hunter found to control the 2nd pump to come on automatically at low lift supply to the IP say 4psi, with a manual on when towing heavy.

CR No casting flaws in mine, I had mine machined for straight thread A/N fitting vs pipe thread
 
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Discussion Starter #6
I was going to put the same barbed fitting in mine until i discovered i didn't have a 1/4" NPT to thread the hole. Thats when i also discovered that the 1/8" NPT brass pipe nipple i had on hand had the same ID as the barbed fittings so i tapped that instead as the 3/8" fuel line fits it perfect and no need for a barb fitting with those low pressures.

The fitting i put in the IP was just picked up at the hardware store, same as original IP fitting on the bottom and even has the O-ring seal on it and has a 1/4" NPT hydraulic fitting on the other end with swivel, just needed to be drilled out. I should have taken pics with them laying sideways, i'll grab a shot in the truck and post it.
 

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Discussion Starter #7
Additional images.
 

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Good work CR, Heath sells a direct replacement HO pump no plumbing changes from OEM, also been looking at Kennedy's HO kit with new power relay, whatever repacement you decide to go with it needs to be a flow on fail design; that will allow IP to pull even if pump isn't running.
TD,

Would you happen to have the specs of the Heath or Kennedy pump off hand?
 

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Discussion Starter #9
Just got back from some testing, it would appear i need some more volume to my IP.

I had my gauge plumbed in between the filter and IP on the line that feeds the IP, here's some results. OEM Fuel filter isn't new but its not got more than 3k on it at this point.

Idle = 3.5 - 4 PSI
WOT = 0 - 1 PSI

Black smoke? Yup got lotsa that stuff!

TD what are the flow comparisons on JK's or Heaths pumps to OEM? Looks like i'm in the market for some more volume and maybe a few more PSI too!
 

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Idle = 3.5 - 4 PSI
WOT = 0 - 1 PSI
Mine would idle at 7 and drop to 0 under accelleration. This is why I plumbed to OEM pumps in paralell. Now the idle PSI is still 7-8, but never falls under 2-4 under hard aceleration and towing conditions. If I were to upgrade the lines to and from the pumps I think things would be even better.
 

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15gph @ 3psi is rating in GM manual test for good LP, I don't know what Heath's rated at; his site only says high output, Kennedy's is what he uses on DMAX so it should feed ours plenty, more $$$ than OEM.

You might want to try a new stock pump, mine did as yours 4-5 idle 0-1 WOT my lift pump had been changed the previous year, when I replumbed, my idle went to 6-7, and WOT never goes below 2 psi.
 

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Great thread. IMHO I agree and think more flow helps under load and when trying to boost performance to upper levels.

Not changing direction but along same idea: What about fuel temperature? I think more flow will reduce fuel temperature. It won't sit in the fuel manager as long and will circulate back to the tank. Cooler fuel will be a little more dense and thus have more power. Also hot fuel looses some of its lubricity compared to cooler fuel. I think really hot fuel starts to kind of break down maybe sort of refines itself or breaks down some in the fuel system. Read thats what some of the black stain is on the filter element "asphalt" coming out of hot fuel???? I don't know actual numbers though. I have seen different things different places.

I think the IP really heats the fuel up to inject it and the injectors recirculate some and this is where the "asphalt" comes out. But cooler fuel to the IP I think helps.

Anyone adding a fuel cooler or changing the location of the factory fuel manager. Maybe a cooler place out of the "V" of the motor?
 

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Discussion Starter #15
1 more thing to add.

When completing this mod i would strongly recommend before hooking up the final hose to the IP end that you should run the lift pump with the hose in a bottle to catch any debris before you hook it up. This is a good precaution to take so no unfiltered foreign material is pushed into the IP.
 
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Discussion Starter #16
TD or anyone, what is required to make the change to either the D'max LP or the Cummins pump. In other words what changes need to be done to fab in either pump?
 

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I'm been thinking along these lines as well CR as I'm about to try a homebrewed version of your 92mm fuel pump. My inclinition is to buy a $150 fuelpump that can supply 15 psi and a high GPM at ~4 amps draw, and ditch the stock GM filter for two aftermarket unit whose elements cost ~$3 each 10/5 micron.
 

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Discussion Starter #18
I want to do this today as i have the time. I was going to ditch the OEM filter set-up after doing the mod to the outlet but was wondering what to do with the WIF wiring and heater wiring and if left unplugged will they have any effect on what the ECM see's?
 

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Had mine unplugged on the '94 for over a year without incident.
 

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Discussion Starter #20
I went to Napa today looking for a Cummins or D'max pump. Only pumps he had listed for either were in the tank or mechanical.

Someone got some part numbers for these pumps mounted inline & electric???
 
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