larger plunger/head assembly

[jwspin]

where can i get a larger plunger/head assembly for an idi 1.6 td?

-jared

[vwmike]

What size are you looking for?

[jwspin]

im not sure exactly. i was figuring between 10 and 12 mm. im going for more the most hp i can get out of a 1.6td and i would like to build the motor and pump before i even install the engine.  so prob bigger is better as of now.
im new to diesel mods but they are more basic than moding gasoline fuel injection systems from what i have learned so far.
are most diesel pumps the same layout? could i use a plunger/head from a different brand?
what are others experiences with different size plungers? i have read about some tdis with 12 mm pumps.......


-jared

[vwmike]

Diesel tuning is much simpler in many respects. I did gas stuff for about 8 years before I ever owned a diesel and really had a reason to care. It's nice not having to worry about engine knock. Many different vehicles used the same style pump. Some parts are interchangeable between brands and models of cars. These pumps are commonly known as the Bosch VE pump and used on anything from Earlier Cummins Diesels to Ford Ranger Diesels (which I beleive used a mitsubishi diesel or something like that). The Ranger (rare) may have a compatable 10mm pump head, as will some Peugeot 505 TD's. Not all of the 505's had 10mm pumps. Some were 9mm. It's quite possible that only the automatics were 10mm and used smaller nozzles for emissions reasons. I'm working on getting some NEW pump heads of various sizes but they would be about $250. If I can get a 12, I was thinking of getting one for myself to try it out.

[jwspin]

does anybody know of any sources for 12 mm pumps? part numbers would also be very helpfull.....thanx in advance

-jared

[RedRotors]

I have a 12mm kit for tdi and one for IDI.. PM if interested.

Marc/

[jwspin]

keeping all variables constant how much more power will you get from a 12mm pump versus a 9mm?

-jared

[fspGTD]

Going from a 9mm to a 12mm plunger would make for an increase in pump displacement of 78%.

[Edit:] and also, for changing from a 9mm plunger to...
* 10mm: would give a 23% increase in pump displacement
* 11mm: would give a 49% increase in pump displacement

Power would increase proportionally, provided you were able to feed it enough air to burn all that fuel.

So, let's say that for a particular camplate, we were to find that a 9mm plunger with maxxed out governor adjustment and wide open throttle and enough airflow could produce 150hp.  With enough airflow, power could then theoretically increase up to 184hp with a 10mm plunger, up to 223hp with a 11mm plunger, and up to 267hp with a 12mm plunger.

[jwspin]

that is what i was thinking but i figured it sounded too good to be true. now besides theoretical power what "real world" power have people seen from changing the plunger on their cars? and what sizes have you all used?

-jared

[Josh]

Wait wait wait a minute here,

   Doesn't the engine run into a ceiling when the cylinder's available displacement can't handle the amount of fuel and air being shoved into it without causing quite high EGR temps?  Or have I missed a basic diesel concept here?  

   Thanks for educating my dumb arse, y'all!

   -Josh

[fspGTD]

Correct, you need air and fuel to have combustion.  If you are already on the verge of smoking and you add more fuel, it will likely add some power but it won't be the full amount, and it will smoke more, and operate less efficiently.

There are quite a few ways of increasing airflow besides displacement increase however:  Revv-limiter increases, ported heads, and camshafts all would increase airflow while keeping the same displacement.  And of course very popular with diesels, is also adding a turbocharger (or increasing boost pressure and/or intercooler efficiency).

You are also completely correct that adding more fuel also increases temperatures, and those need to be controlled as well to prevent engine destruction.  However, prior experiments with diesel tractor pulling (ref: "Turbochargers" by hugh MacKinnes) tell us that this shold be possible, and with proper intercooling (they used water injection with the really high manifold pressures) we can run as high of a boost pressure as our motors can take.  In general one stage of an axial flow compressor (which is what a turbocharger has) is good for no more than a x 4 increase in absolute pressure.  So to get much over 40 psi gauge pressure, 2 turbos in series become necessary.  Tractor pullers on their direct injected inline 6 diesel motors have done 3 turbos in series, pushing out well over 200 psi manifold pressure.  They found that the limit to boost pressure becomes the force that the engine's pistons, crank, connecting rods, and head gasket, etc can safely take without breaking.

[jwspin]

it is funny that you reference tractor pullers. i am from farm country and tractor pulling is huge around me. when i was building my turbo gas car i stopped by a tractor shop to find a couple silicone conectors and started talking to the guy about what i was doing. he laughed at me and said i was never going to get 125 psi with a wastegate and the size turbo i had. i started laughing at him and said i never plan on going any higher that 15psi. he was completely confused. but ofcourse he has never worked with gasoline engines before.

so do you think that 12mm is overkill for a 1.6td engine?

-jared

[fspGTD]

On my GTD autocrosser I have my 9mm pump maxxed out at stock boost level (intercooled), and it smokes a lot, but EGTs are well under control.  This is on the stock 1.6l camplate (2.2mm stroke I believe.)  I am considering switching to the 10mm plunger just for the heck of it and to see if it might allow a little more power for the same air, but I doubt you'd want to run a setup that smokey on a street machine.  In fact, even at an intercooled 14 psi I was able to make the 9mm pump put out quite a bit of smoke.

Assuming we maintain the stock head and cam, for comparable smoke levels on a maxxed out 12mm plunger with the same 2.2mm camplate, you'd need to boost your 1.6lTD to about 30psi (77% increase in absolute pressure and also airflow in theory.)  To have less smoking on a 12mm pump you would need even more boost than that.

For comparable smoke levels to the maxxed out 9mm plunger at 14psi, with a 12mm pluinger you'd need to run 36psi gauge pressure.

I'm guessing here as I haven't tried this, but let's say we found that smoking of a maxxed out 9mm pump and 2.2mm camplate finally cleared up on a 1.6lTD intercooled at 20psi gauge pressure.  If that were the case, if you wanted to get rid of the smoking a maxxed out 12mm plunger with 2.2mm camplate, you'd need to run 46.5 psi gauge pressure - which at over a 4:1 pressure ratio, may be beyond what is possible with only a single stage turbo.

Couple a 12mm pump with a 1.9l's 3.3mm "stroked" camplate (a further increase in pump displacement of 50%) and there is no question you'd need twin turbos blowing one compressor into the next to be able to burn all that fuel.  :twisted:

[vwmike]

You're making the assumption that there was no LDA in these calculations. 12mm is most likely overkill, but would definitely leave some headroom if you wanted to upgrade later. Do you remember Deo's post a long time ago saying how Blakes truck made 134hp at ~36 psi? I'm fairly certain it was because he was running a 12mm pump, but it's kind of hard to squeeze out all the details.

You also got me thinking a bit more about the VNT. I'd given it some thought previously but I never had one for testing. One of my thoughts was possibly to use a VNT off of a Daytona as it would probably have the same .42 compressor. My only concern is that the range of the nozzle may not be small enough to work properly on the diesel. My car experiences a lot of lag unless I turn the LDA stop screw in which makes it smoke quite a bit. I was also thinking the other day, what about using the vacuum off of the vacuum pump to actuate the VNT canister? I don't know if vacuum varies at all with RPM. If it did that would be great but I doubt it would vary enough. A solenoid and a pressure switch may allow enough control to make it work more or less like it should.

[Mark(The Miser)UK]

On my GTD autocrosser I have my 9mm pump maxxed out at stock boost level (intercooled), and it smokes a lot, but EGTs are well under control.  This is on the stock 1.6l camplate (2.2mm stroke I believe.)  I am considering switching to the 10mm plunger just for the heck of it and to see if it might allow a little more power for the same air, but I doubt you'd want to run a setup that smokey on a street machine.  In fact, even at an intercooled 14 psi I was able to make the 9mm pump put out quite a bit of smoke.
.  :twisted:

 :mrgreen: Jake your old friend Loren once set me a pic of your car under full power with a jet black cone out the back. Unfortunately it only showed a few feet of the smokescreen. Do you have a copy to show the guys here what a 'real' haze looks like? :mrgreen: