New Injection Pump

[AlexDring]

Could someone please explain to me why the pump off the Cummins motor (P-7100) is so spendy. They are like gold for people who want power.

How hard would it be to design a new one? As fast as these things go, I would bet there is a market for them in the diesel world. From what I got from Piers Diesel, the power of the cummins usually is limited by the style of pump.

Thanks. Alex

 

[HydrasportKDA]

The "older" diesel engines used fuel pressures to actuate the fuel injectors. Thus the high pressure pump was the "timing, fuel delivery, everything" of the diesel engine.

While large flowing injectors could be used to allow more flow if the high pressure pump couldn't deliver more flow, the injectors are worthless.

These pumps are sought out because of robustness, ease to modify, cheap to modify (cheap being relative to other injection pumps).

The new common rail engines have adopted the more traditional automotive injection system with an ECM controlling injectors (pulsewidth) and a pump that generates the high pressure.

A site I recommend for more CTD reading is the turbo diesel register.

Lots of guys interested in tweaking the Cummins engine.

 

[AlexDring]

HydrasportKDA-

So how do they basically work? The injection pump that is on the Cummins. They are gear driven, that is given, but if I remember right, the gear rotates a cam. Am I close to the basic operation?

It would just seem logical for one with the time to design an aftermarket pump for those and easily sell them around 1200-1400. There sure is a market for them, since about 75% off all dodges sold since the Cummins was introduced were ordered with the Cummins.

 

[evelrod]

Alex, It's just a matter of $$$ ! No aftermarket supplier is likely to jump in and replicate the Cummins OEM unit.
Two very big reasons that I can think of---RELIIABILITY---It is not at all uncommon to find 'pumps' lasting to a million miles and more. DEMAND---see reason number one and keep in mind that the trend in emission compliant diesels in the future will be ECU controlled units! As to the aftermarket mfgrs v Dodge PU's, after 1994 they went to the ECU controlled injection so it is not in their best interest to build and market a NEW pump for such a small market segment. Rebuilt pumps are currently available and several companies will rebuild/modify existing units but, like you say, a bit pricey!!!

Rod

 

[AlexDring]

Rod-

I see your point. Sure ticks me off though when I look at the prices, but then again anything for a diesel is expensive now days. Almost as bad as parts for a Harley. I mean a simple cam plate that goes into the pump, 150.00, and its a simple plate with a profile, that at the most cost a quater to fab.

I wish it was back like it was before they got popular and jacked the prices sky high. I remember when diesel was alot cheaper then gas, but like you said it pretty much is economics, supply and demand.

Thanks for the input though.