Injection pump upgrade

[detroitdiesel]

On my DB-2 pump, i was wondering if i bore out the plunger holes and machine larger diameter plungers, would there be other things limiting fuel output. I am thinking of doing this to a pump for my turbo diesel red blocked 6.2. (I know this is ford idi area but this section gets more attention than the 6.2/5 area and is with regards to the same pump) My goal is 300HP at the flywheel, and besides going to an inline pump, i think this is my only option.

 

[argve]

simple answer yes... It would increase the fuel delivery.

 

[detroitdiesel]

I am aware of an increase in fuel delivery, but will there be other things like the head passages limiting fuel output? I guess my question kind of is, What would the pump head passages be able to flow cc wise?
Thanks for the responses.

 

[starmilt]

detroit check out the moose pumps unless I am mistaken they build them for chevys too.

 

[dieseldummy]

What you are describing is possible, but not as easy as you think. To do it right you'll need to find a pump shop or someone who can re-chrome the plungers and rotor. otherwise it won't work for long. To get 300hp at the engine there are several options. A db2-4974 marine pump will do it as will the 4 plunger unint.

 

[detroitdiesel]

Well, I plan on boring out the hole just smaller than what i want it. i will then make a simple hone and use it to make the bore diameter do my exact likings, as well as create a finish that will seal to the plungers well.

Also, why do the plungers have to be chromed? Why couldn't i just machine some out of some hardened steel?

Thanks for the input!

 

[pybyr]

besides going to an inline pump, i think this is my only option.

Are there inline pumps that'd work on these V8s (without major custom engineering)?

 

[Diesel JD]

I love pump mod talk! I don't know what size the 6.2 stock plungers are but the 7.3 IDI goes up to .0031" and I think the ones in the Deere DB4s are .0033" I recall one guy was thinking about having the bores machined for the plungers out of a V8 American Bosch pump for the old Mack B- Series....

 

[dieseldummy]

Well, I plan on boring out the hole just smaller than what i want it. i will then make a simple hone and use it to make the bore diameter do my exact likings, as well as create a finish that will seal to the plungers well.

Also, why do the plungers have to be chromed? Why couldn't i just machine some out of some hardened steel?

Thanks for the input!

I tried to do what you are thinking of doing. I was able to get a pump to pump some fuel, but it didn't last long under pressure of poping injectors. The reason injection parts are chromed is that they operate under extreme pressures so they need an incredibly hard surface to keep from wearing and keep extremely close tolerances.

There are pumps out there that have been custom modified for huge plungers... you just have to fork over the $$ to get one. I've heard reliability leaves something to be desired as well...

A stock 6.2 pump has .290" plungers in it, a stock 6.5 has .310", the marine pump has .330", and I can't remember the spec for the 4 plunger pump. Basicly a 6.2 pump is good for around 230 flywheel HP, 6.5 pump 290 flywheel HP, marine pump 350 flywheel HP, and the 4 plunger around 400 HP. These are rough estimates based off past experience and knowledge passed on from others.

If you have extra time, an old 6.2 pump, and access to some equipment I'd say go for it. Maybe you'll find a way to make it work without chromed parts

 

[jwalterus]

i will then make a simple hone and use it to make the bore diameter do my exact likings, as well as create a finish that will seal to the plungers well.

wouldn't a small brake cylinder hone do the same thing? they have one at Sears here that goes down to 1/2" for small passenger cars....

 

[detroitdiesel]

Are there inline pumps that'd work on these V8s (without major custom engineering)?

The answer to your question is no. Although it is possible. I have seen a 6.2L with a inline 8 simms pump on it. the guy said i could get the pump and adaptor for around $1500

 

[detroitdiesel]

wouldn't a small brake cylinder hone do the same thing? they have one at Sears here that goes down to 1/2" for small passenger cars....

No, 1/2 is to big. Like diesel dummy said, the plungers are about .3 inches in diameter

 

[Diesel JD]

I was thinking the bores were in the neighborhood of 30 ten thousandths instead of thirty thousandths of an inch. Maybe I have been quoting incorrect #s all this time. This is interesting info. That means a 6.2 DB2 pump is just like a stock 6.9 pump plunger wise and a stock 7.3 pump is like a stock 6.5 DB2. The 6.5 marine pump and 4 roller pump are just like the Deere DB4s plunger wise. There's probably a lot we IH/Frd guys can learn from the GM diesel crowd regarding the pumps since there are 6.5 turbo diesels out their with marinized DB2 and DB4 pumps throwing down big HP. I bet a 6.9 studded with a big turbo and intercooler, lowered compression and a DB4/DB2 hybrid could make 300 wheel HP and still be pretty streetable.