Internal pump mods diy

[Redblock]

Posted in the drag race section, but no replies….6.2 and 6.5 forums look dead also, looking for some advice so I can get this back together on my days off…



I’ve got a few performance questions for a hot street truck.
Ill attach some pics of the pump ID.

Quick history story, i have a built 6.2 and I did the following to the 2831-4911 pump :
1. Removed leaf spring
2. 3/8 inlet
3. Shaved off about 1/4-1/3 of the gov weights, evenly on all of them.
4. 6.2 gov spring assembly, nut shaved down and rod maxxed out. Also added about 1/4” to the end of the rod pushing on the hobo.

I have very little experience doing these mods on these pumps, so I am just shooting in the dark. I get the theory of operation, but not a ton of experience. Anyway, it did not really do as much as I had hoped. It did fuel more, still not enough, but the fuel response and rpm still aren’t enough. Guessing its only turning 4000-4200 or so, and it just kind of runs up and flattens out.
Why did my old raggedy n/a 6.2 rev up and ba-ba-ba-ba at the top end, where this one just runs up and flattens out smoothly? Just curious about WHY the difference.
Hard to tell alot of performance “gains” because that engine is in a heavy lifted square body.

Now to the point..

The new truck is a square body shortbed stepside, lowered, also a built motor. I have this other pump, i have pulled 3 gov weights (every other), removed the leaf, 3/8” inlet, 6.2 gov spring, shaved nut.

I havent put it back togather completely just in case there is more “I” can do.

Can any gains be made from the smaller gov spring? Adjusting, bending, etc?
Removing the metal tab where the idle spring contacts?
How about machining a couple thousands more on the metering valve? Or somehow getting it to turn further?
What about the advance piston/linkage mods? Add/remove material to the cam/ramp?
What about static timing setting for performance?

Mainly looking for quicker revs, less “governing”, more fuel, and more rpm.
Dont really want it not reliable, but i do understand it may induce some quirks.
I am saving for the big pump from CCD, but in the meantime i am trying to real world learn “if you change this, it does this” type thing.

Engines i have covered, but pump wise…..clearly I know enough to be dangerous lol

 

[IDIBOBS]

What is the end game result you’re looking for? Do you have injectors to move more fuel?

 

[Redblock]

More fuel, more rpm…

Injectors on the 6.2 aren’t a bottleneck. We dont really have any options like the Ford guys, other than full custom type thing. But the factory 6.2/6.5 injectors have been able to support 500hp “from everything I have ever seen”.

Mine are marine’s set at 2500 psi. I have a popoff tool so I can set them wherever i want.

 

[Black dawg]

Played with a factory turbo ford pump years ago, we were able to get what felt like significantly more fuel out of it, but never removes the leaf spring. I think all we did was cut the one side of the roller holder shorter so it could move farther before being limited by the leaf spring. Been a long time, have to think on that for awhile.

Another thing I have seen is that the mechanical linkage on the ext of the pump being adjusted slightly limited.

 

[Redblock]

Played with a factory turbo ford pump years ago, we were able to get what felt like significantly more fuel out of it, but never removes the leaf spring. I think all we did was cut the one side of the roller holder shorter so it could move farther before being limited by the leaf spring. Been a long time, have to think on that for awhile.

Another thing I have seen is that the mechanical linkage on the ext of the pump being adjusted slightly limited.

Hmmm, i looked at the roller shoes when I had it apart, they look pretty thin as is, i think those are ceramic? If anything maybe machine the plungers shorter to get more fuel drawn in the pumping chamber? I dont know if that would make them get hung up or possibly get cocked in the bore?

The exterior linkage has the high rpm adjustment screw. I have it maxxed out on the throttle “travel” to roll the gov sleeve as much as possible.

I dont know if there is a way to make the gov travel further on the guide rod? If you did, that would push on the smaller spring “thing” off to the side and rotate the metering valve more. But I dont know if that would actually do anything, maybe its already turned as far as it can? Here is a pic of what i’m talking about, i put an orange mark on it.

You must be registered for see images attach

Im gonna guess and say that would turn the metering valve sooner/more, possibly making the throttle more touchy. Which i’m gonna say is fine by me (for now).

 

[Black dawg]

Its been so long. I swear I remember modding the shoes and they were steel. I do remember talking about making the plunger shorter, maybe he did. Just dont remember.......

 

[Clb]

Have you read about modifications that can induce a runaway?

I think Agnem wrote some great stuff once on I think fte or one of his other haunts.

 

[Redblock]

Clb I have not..in my infinite wisdom (hahaha) i cant see where I could have a runaway “as long as” something doesn’t stick, mainly the metering valve, which means the govenor assembly would have to stick.
Im not really doing anything that could cause a “sticking” situation I dont think.
I’m all ears though, if anyone has any tips, good or bad.

 

[Rocknit4x4]

not sure if you saw this thread but it might be helpful

CDD DB4 Pump Build​

 

[Redblock]

Man thats a good one, thanks!