Engine/Transmission (1994 - 1998) 12 valve fuel heater assembly help

[BarryG]

I am looking for a 12 valve heater assembly it does not have to work. Or if someone has one laying around that they dont want to part with could you measure the thickness of the mounting flange.



I am getting ready to install a cam in my 24valve and want to convert to a 12 valve style lift pump. I have not seen one in person but it sure appears from some pictures in manuals that the lift pump requires that heater assembly as a spacer between it and the block. I dont mind fabbing up a spacer but have no idea how thick it needs to be.





Any help would be appreciated

 

[Missouri Mule]

When I been down under the pre-filter/heater housing looked like it was seperate from the lift pump.

 

[hsmith]

It is a complete separate piece away from the lift pump. Don't even consider using one. Most of us 12 valvers take them out anyway as they cause small leaks. It may be an issue for you seeing where you are, but don't think so.

 

[hsmith]

Brain fart, are you asking about the thickness of the bracket maybe?

 

[bmoeller]

No need for a fuel heater in TX. Better be running one in CO though. You'll regret it if you don't. Been there, done that.

The fuel heater bracket is attached to the mounting studs for the lift pump, but nothing more. Don't recall how thick the bracket is though. Maybe 1/8"?

 

[BarryG]

Missouri Mule- yes it is a seperate piece and I dont need it except for the mounting part for a spacer.



hsmith- If you take it out how do you account for the space it takes up between fuel pump and block? Do you put in a spacer? And yes (sorry I wasnt clear about that) I was asking about the thickness of it so I could possibly fab up a spacer instead of hacking up and using the fuel heater assembly mounting area/bracket as a spacer.



bmoeller- I am not going to use the heater I just need to use the bracket or mounting area (sorry being 24 valve guy I actually have no idea what this thing looks like) as a spacer for the fuel pump. Near as I can tell from the pictures and talking with a parts guy is that the bracket/fuel heater assembly mounting area is sandwiched between the block and the fuel pump. I just need to be able to have a spacer that same thickness to make up that amount of thickness so the fp doesnt go to far into the block.



This just in - A member "fishin guide" tells me on his conversion (24valve lift pump to 12 valve lift pump) he used a spacer that is available from Cummins with updated bolts to use when taking out the heater assembly. He even had part numbers for them.



This is going in an 01 24valve which has an integrated fuel heater and fuel filter assembly that I am going to use. I just want to use the 12valve lift pump to replace the electric fp crap that came on the 01 and since I am putting in a cam it will now be possible for me to do that.

So I will be calling Cummins here shortly and see what they have to say about these part numbers fishin guide gave me.



Thanks a ton for the help

 

[Joe G.]

It's a good idea to keep the pre-filter strainer in the fuel heater assembly. Remove the fuel heater from the assembly (it looks like a hockey puck) and put the assembly back together without it.

 

[PRohr]

If you take a 3/8" allen wrench you can take out the "stud" or extension for the fuel heater and then screw the pre-filter right to the housing.

 

[vsimkus]

For what it's worth, the thickness of the pre-filter bracket that goes between the block and the pump is 5mm.

 

[tp0d]

Not to throw a wrench in your plans, but doesnt the 12v pump generate way too much pressure for the VP44?

I thought the limit was 15-20psi on the VP, where the 12v pump easily makes 50... ?

-j

 

[Joe G.]

If you are going to switch to a P7100 injection pump the 12 lift pump will work. If you are going to use it with the VP the pressure spikes caused by the pump piston will probably kill the VP.

 

[PRohr]

Does the 24V cam even have the eccentric on it to drive the mechanical pump?

 

[BarryG]

The stock 24 valve cam does not but I am putting in an aftermarket cam that does have the pump lobe on it.



I have checked with several people that have made the conversion and some have used a regulator and some have not, some have used a bypass and some have not. The couple that said they ran it straight as in no bypass or regulator said it has been on for over 50k and the other over a 100k and zero problems so far one was running 32psi and the other in the high 20's. No one has had a toasted VP or at least fessed up to it. I am reusing a bypass from my previous setup that was set at 15psi. Will see if it can keep up it may very well be able too. If I need to I will regulate it and or snub it to chill the pulses once I see what they are like.