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Engine Specific Info and Questions => IDI Engine => Topic started by: jwspin on July 19, 2005, 12:02:24 pm
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where can i get a larger plunger/head assembly for an idi 1.6 td?
-jared
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What size are you looking for?
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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
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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.
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does anybody know of any sources for 12 mm pumps? part numbers would also be very helpfull.....thanx in advance
-jared
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I have a 12mm kit for tdi and one for IDI.. PM if interested.
Marc/
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keeping all variables constant how much more power will you get from a 12mm pump versus a 9mm?
-jared
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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.
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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
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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
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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.
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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
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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:
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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. :D
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.
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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:
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Half the battle (and the primary reason for the large plunger) is getting the fuel in soon enough to ensure a good mix and a clean burn. The maxed out 9mm setup will be pushing in a bunch of of fuel late in the cycle, where it tends to create smoke rather than power. A maxed out 9mm pump will smoke WAY more and produce less power than a 12mm pump delivering exactly the same quantity.
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VWMike: By "maxxed out governor", I am indeed assuming in all boost level scenarios that the LDA rotation and depth are maxxed out.
Mark The Miser - although I don't think it's the pic you are referring to (I don't think I still have that one!), here is one of my more recent "smokey" favorites, :wink: from the 2003 SCCA Solo 2 Nationals:
(http://www.imagestation.com/picture/sraid83/p9096be55ac139d34ec6bca060e467f95/fad2d912.jpg)
QuickTD: It seems like while more pump capacity indeed can shorten the injection window and thereby increase efficiency, going too far in unused displacement could also be a double-edged sword, where the power loss from the additional parasitic drag off the injection pump to drive the larger plunger could be greater than the power gained from the efficiency increase.
I am curious what the optimal pump size would actually end up being, and would be interested in hearing about any experiments (TDI, IDI, or otherwise) done with plunger upgrades. Shortening the injection window is indeed an important consideration of mine for upgrading the plunger in my GTD Autocrosser.
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Jake, im running a 12mm head/plunger in my TDI Golf, ok it's a TDI, but im also running big injectors with stock ECU program at 15psi. I have a little puff of smoke when starting at a stop, and little smoke between gear shift. At WOT, running at 110mph ,i have 15psi substained and i have an haze at the tail pipe. I went from a 10mm to an 11 and then a 12mm and let me tell you that the power is very linear and very strong until 4500rpm ( limitted by the ECU ). I don't have excessive smoke.
I agree with Bruce that one of the main purpose to upgrade the pump is to get much more fuel in a shorter window. I have a friend here that run his 1.9TD with a 12mm pump @22psi, the smoke level is tolerable and his ride is real fast.
So i don't think that a 12mm is too much for an 1.6 or1.9TD if the pump is correctly set.
Marc/
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Thanks for the info, Marc. My 1.6lTD Rabbit GTD Autocrosser is limited to stock turbo and stock boost pressure (9-10psi) under its class rules. We are however free to do any fuel injection modifications at all. :) What are your thoughts about using a 12mm plunger on this application... think it would be most optimal plunger size?
PS - keep in mind your TDI at 1.9l displacement and 15 psi boost is ingesting significantly more air per stroke (I estimate about 42% more) than my 1.6l at 10psi.
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You might try the 10mm first, it might give you an idea, but beeing limitted at 9-10psi, i think that the 12mm will smoke. The 12mm will need the later camplate from the 1.9TD, because the plunger foot is a little bit bigger than the 1.6 and won't sit in the camplate as well as the 10,11mm TDI head/rotor.. I don't know about the other ones.. Some ajustments on the pump will be needed to tune the idle, but im sure you won't have any problem to do this.. :)
Marc/
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Thanks for the info! I am looking forward to trying the 10mm. :P
PS - are the 12mm plungers only compatible with pumps that have the larger input shafts, like the ones in the TDIs and later 1.9lTD pumps?
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PS - are the 12mm plungers only compatible with pumps that have the larger input shafts, like the ones in the TDIs and later 1.9lTD pumps?
It's not the input shaft that is the problem, it's the recess in the camplate that isn't large enough. If you put in a late model 1.9TD camplate you're all set.
The late model 1.9TD pump does not have the large 20mm input shaft, but does have some similarities to the ALH TDI pump. The timing pulley attaches to the pump with a 3 bolt hub. The "nose" diameter is also larger and will not fit the early style pump bracket.
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FYI - I took apart the mitsubishi mid-80's pickup 10mm pump to do some learning about its internals and do some comparing with the 1.6lTD (from a 1984 Jetta) pump parts.
Although the camplates were constructed differently (the mitsubishi one seemed like a heavier piece), the displacement of the mitsubishi camplate is the same 2.2mm as I believe is on the 1.6 camplate. From the picture it seems that the mitsubishi camplate has a slightly softer profile than the VW (IE: slower movement of the pump head), but it's hard to be certain just from looking, as they are pretty close (1.6 vw on left, mitsubishi on right):
(http://www.imagestation.com/picture/sraid195/p6219ae3bb2496b6ec5be8f5736ae1fb0/f12eedb5.jpg)
The two camplates also have as closely as I can tell, an identical recessed diameter for the "plunger foot". (Tested by crudely measuring, as well as test fitting the same plunger into each and observing equal amounts of "play".) The plunger drive pin in each is also a matching 3.5mm diameter. (1.6 vw on left, mitsubishi on right):
(http://www.imagestation.com/picture/sraid195/p6cdff3439e02fde7535941a4d2d90c05/f12ee54f.jpg)
Takeaway: given the matching plunger foot diameter and similar camplate displacement, the 10mm mitsubishi plunger may be a suitable swap-in upgrade for a 1984 1.6TD VW pump (for either maintaining the original 1.6 VW camplate, or swapping the mitsubishi camplate along with the plunger.)
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Interestingly, the plunger return springs were not the same. Although nearly identical in free length, the mitsubishi springs obviously had thicker gauge of wire, and also had one extra coil (1.6 vw on left, mitsubishi on right):
(http://www.imagestation.com/picture/sraid195/p6f744dd6b9d6607820fe5759036249f0/f12ee296.jpg)
Looking at both, I thought the VW one might be good for some more pre-loading and lift, if the wire material was strong enough. Well, it turns out that the wire material was not strong enough to remain undeformed after being coilbound. It actually deformed quite a bit. :shock: (in pic below, two vw 1.6 plunger springs are shown, the one on left hasn't been coilbound and the one at the right has)
(http://www.imagestation.com/picture/sraid195/pabce3d149a0039b105815487e802ab2a/f12eea71.jpg)
Can the mitsubishi spring take being pre-loaded to coilbind? I'm guessing it can get closer given it has less travel to go and also some thicker (& probably stronger) wire, but I don't wish to test it on my only pair of these springs. I wouldn't mind testing and comparing the spring rate of these two different springs, if I can rig up such a test though.
How much pre-load the plunger return springs should be set up with, and deep the plunger should be set up, I am not certain. If anyone has any advice or VE technical service manual information covering this (any information on the topic - what methods are used to measure it and set it up, what the factory recommended settings are, etc), please let me know, as I would be very interested in it. I have a feeling that it's pretty important and is something that the trained/certified VE pump rebuilders check and set. I would really like to know what I'm doing and not blow up a pump if it could be avoided. Thanks!
It is likely that a plunger upgrade test of some sort will be in my future after I get my Rabbit autocrosser up and running and the fresh rings broken-in, and maybe the custom intake manifold fitted and tested.
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Jake what do the plunger return springs look like when ther are installed in the mitsubishi pump? You can see them when the head assembly is installed with the top cover off. Its really important that when you swap head units that you keep the return springs that came with the head assembly, not the ones in the pump you are swapping them into.
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the part numbers for many springs are the same across the board, from 8mm on up to 12mm.
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What's the bosch pump number Jake?
Marc/
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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
Can you post the formula you used to find this?
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Can you post the formula you used to find this?
πrē=area of plunger.
Doubling the area for a given camplate lift will double the displacement.
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Marc - the mitsubishi pump is a Diesel-Kiki, NP-VE4/10F2100RNP167. Pump no 104640-3080.
The ID plate:
(http://www.imagestation.com/picture/sraid195/p2c11f291756514ee0d69c1159cd07018/f129c944.jpg)
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Thanks Jake for the info, but unfortunatly, i don't have access to diesel kiki parts... :( Even with the Bosch formula, i can't find nothing..
Marc/
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i can turn mine down so it doesnt smoke (12mm)
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So are all larger pump heads from TDI's? If you are running a 1.6 IDI, you have to stay with a 1.6 or 1.9 IDI camplate, right?
If I were to hypothetically convert my 1.6 IDI into a 1.6 TDI and keep my 1.6TD pump, would going to a TDI rotor and camplate be all that was needed to run TDI injectors?
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Can import what engine you convert into a TDI engine, you absolutely need a M-TDI pump, the 1.6TD pump does not work on a 1.6 hypothetic TDI, euhh.. that work, but with very poor power and a lot of smoke, bad idle etc.....
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So a tdi camplate and 10mm tdi pump head wouldn't work on a 1.6TD pump?
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with some matching parts, yes.
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Tintin means the stock TD pump won't work unmodified. You would need a TDI head, cam plate and I think a different or modified control lever and a modified governor wouldn't hurt either.
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Awesome. Here's another general question:
Is there any real difference between a TDI pump head and an IDI pump head besides TDI's having a larger range of plunger sizes?
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I think the plunger foot is different except maybe on some AAZ pumps.
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The bigger foot plunger has been standard at bosch for a few years, the older pump have a small foot plunger and small drive pin.
I found in an old european pump for some application with 11 or 12mm, the plunger foot are small but with a bigger came plate drive pin, if I try to put this plunger in a came plate with small drive pin, that fit but It's tight, I think that the old cummins pump here, are similar.
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What sort of mods for the accelerator lever are required? You mean like changing the angle of the levers for the max fuel adjust and the governor lever?
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Isn't turning the fuel down sort of the same as picking your foot off the go pedal a little?