Pumps: 1.6TD vs. 1.9TD

[neich]

Hi,

I am still searching for info about differences between these two pumps. Specifically between the 1.6TD (JX) pump and the AAZ pump. I know, there are different models for the AAZ.

The first information that I have found in the old forum is that the 6th digit in the pump number correspond to the plunger size. Both pumps have a 9mm plunger, so this is good news.

If both pumps have the same plunger, and assuming that both pumps deliver the same fuel pressure, the only difference could be in the camplate profile ( I assume they have the same lift since I assume same pressure). Am I right ? I know that there is also the issue of the shim at the end of the plunger that could influence the pressure.

BTW, does the three last digits of the pump number contain more useful information ?

Thanks
Nacho

[QuickTD]

The 1.9TD pump has quite a bit more camplate lift than the 1.6TD.

[neich]

And that means that the 1.9TD delivers much more fuel pressure than the 1.6TD pump ? Or are other factors that I am missing ?

My uderstanding was that fuel pressure was fairly similar, but my knowledge is quite limited.

Thanks
Nacho

[QuickTD]

The total camplate lift (and plunger size) determine the maximum volume of fuel that can be injected per stroke. The rate of camplate lift, injector size (hole size on DI injectors, annular gap on IDI), injector spring rate, injector spring preload, plunger size, the quantity injected, the temperature and viscosity of the fuel and the rpm that the engine is turning all play a role in how much pressure is developed at the injector.

 In actual operation, I would expect the 1.6TD and the 1.9TD would develop very similar pressures. The 1.9TD pump with its higher camplate lift is capable of delivering a larger volume of fuel per injection stroke.

[neich]

Sorry if my knowledge about fuel pumps is too basic, but there is still one thing that I don't understand, even after reading "Diesel Fuel Injection" from Bosch.

All the VE pumps with the same plunger diameter have the same displacement ? Moreover,  are the inlet port at the same position ? I would say that the inlet port position determines the maximum amount of fuel than can be injected.

Because if everything is the same, changing the 1.6TD camplate for a 1.9TD camplate should give you pretty much the same that a 1.9TD pump ? Maybe the delivery valves would make a diference.

Thanks again
Nacho

[QuickTD]

All the VE pumps with the same plunger diameter have the same displacement ?

No, the camplate lift also determines displacement. Think of it like an engine, plunger size = bore, camplate lift = stroke.

 
 Moreover,  are the inlet port at the same position ? I would say that the inlet port position determines the maximum amount of fuel than can be injected.

Inlet port position would only be relevant if the ports were still open when plunger lift began, which I don't think they are. As far as I can tell the inlet ports (4 of them) and the outlet port (only one) vary only in width from one plunger diameter to another. I'm guessing the purpose of this is to acheive the same port opening and closing timing with the different plunger diameter.  

Because if everything is the same, changing the 1.6TD camplate for a 1.9TD camplate should give you pretty much the same that a 1.9TD pump ?

Exactly!

[neich]

Because if everything is the same, changing the 1.6TD camplate for a 1.9TD camplate should give you pretty much the same that a 1.9TD pump ?

Exactly!

I see. So , anyone has a 1.9TD camplate to sell ?

;-)

Thanks
Nacho

[caddy]

Because if everything is the same, changing the 1.6TD camplate for a 1.9TD camplate should give you pretty much the same that a 1.9TD pump ?

Exactly!

I see. So , anyone has a 1.9TD camplate to sell ?

;-)

Thanks
Nacho

i check it :wink: