VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: Patrick on January 13, 2005, 05:21:19 pm
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I've been reading through a lot of back posts. My experience with heavy truck engines in the past leads me to believe that diesels will handle a lot more fuel/boost/heat at higher rpms because of the larger quantities of air helping to cool the whole thing. One of the limiting factors for efficiency then becomes flame times. In the older big cummins engines, the only way to change injection timing was to change cam timing, because the injectors were fired by a push rod off the cam just like the valves. Same cam. Varying the cam timing would move the peak torque up or down. In theory, you could do the same with the stock cam in a 1.6 or 1.9 to help. Get the valves open a little sooner at higher rpm . Would hurt at low revs, help at high revs. Don't think anyone builds a degree wheel for a diesel volkswagen though!
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I've thought about this a bit as well. It gets to the point with fueling and boost where you can only go so far before the gains are minimal. I would think that the cam would be a limiting factor, although the compression ratio and resulting piston-to-valve clearance limits what the cam can do. TDIRs has come up with different cams for TDI's, and I think there are a few companies out there with TDI cams. But I think the TDI has a little more clearance than the IDI's do. I would think that playing with cam timing a little on a high-rpm engine would be bound to produce some results either way. I'm pretty sure any adjustable timing gear for an 8-valve engine would fit the IDI diesel.
Brendan
84 Scirocco 8v
00 Camaro L36 M49
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I'm pretty sure any adjustable timing gear for an 8-valve engine would fit the IDI diesel.
Brendan
84 Scirocco 8v
00 Camaro L36 M49
Nope,
1) Belts wider on the diesel.
2) ID bore and taper are different
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Adjusting would be easy with no key on the cam. Question is, how do you know where you put it? Would have to build something that measures directly of the cam.
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Patrick, for some background material, read this post (http://www.hostboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=4037&t=425) from our old forum. Tdrs and others discuss using a GTI cam in a TDI, but the same philosophy may be applicable to an IDI engine for getting more air into the engine at higher RPMs. OTOH, advancing the cam may turn out to be dicey due to the already very tight valve-to-piston clearance, so going to slightly higher lift and duration, as with the GTI cam, may be the only realistic option.
That having been said, there may be more room than I think, so when I get home this weekend I'll post some digi-pics of the adjustable cam on the GTI motor in my CSR. You guys will all instantly recognise the cleverness of this approach, and I can just see it now...bent valves everywhere! ;)
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It turns out that I have the pics on my laptop, so have started a new thread on the DIY adjustable cam pulley in the FAQ section. Have fun! ;)
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Neat idea, but more work than we need on a pulley that's not keyed to the cam. If someone really wanted to make it easy, all they need is an adjustable camstop to set the timing, right? trick is doing the work the hard way (measure TDC and opening of the intake valve on#1) and move the cam, do the measurement again, figure out how many degrees you moved it,(eg 3degrees advance) make a jig to fit, and you have a new camlocking plate for 3 degrees advance. Could be a lot of messing around the first few times (say 4 jigs at 1,2,3,and 4 degrees) but would make the engine much more tunable.Could be easier though. If the timing is set factory, and you move the belt 1 tooth on the cam, where do you wind up? (360 degrees divided by the # of teeth on the gear).
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i will post some picture of my special puley to fit a gti came shaft on a tdi head.
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back in the dark ages, I bent a full set of exhaust valves advancing the cam what looked like just a little bit on a 1.6. Right now, I'm running my 1.9's cam advanced just a hair. That is to say, with the cam locking plate installed, there's a little bit of slop. with the plate installed, I moved the cam forward (adv) to take up this slop. The engine has good tug down low, and flattens out a bit after 3500 rpm. Admittedly, this could just be the nature of the (1.9) beast, or a pump tuning factor. The engine's still not broken in yet, and I haven't played with tuning yet. To really qualify this, i'll have to do back to back comparisons with the current setup followed by taking up the locking plate slop in the opposite direction. Will post more later.
please re-read my first sentence and beware!
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Well, part of the reason I asked is because I put my 1.6TD together without a locking plate, and I noticed after everything was tightened up that it was advanced a little (groove not dead level across). Never having messed with a volks diesel before, I didn't realize the sprocket wasn't keyed to the cam. I figured you just got what you got. Then I started reading here. Steep learning curve! Anyhow, the engine is a little on the lazy side on the low end, you can hear the turbo spooling up pretty good at about 2400 or so, and things really start to happen bigtime at about 3000. The pump (to the best of my knowledge) is completely untouched, and I think the timing on the pump may be a little retarded, but it's real close. (running about 750-800 km on 45l of winter fuel.) This is in a 4 door 92 jetta with air and power steering, over 500,000 on the chassis.
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if anything, advanced cam timing should improve bottom end at the expense of top end. if you're getting sluggish engine performance, checking pump timing with a dial indicator and tuning it's settings may well be in order, especially after having the belt off.
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Okay, maybe I said it wrong.What I should have said is that the pully is advanced on the cam, hence the cam is retarded, and yes, I need to put a dial indicator in the pump, just haven't got around to it yet! :oops: I can't be very far off though, the car starts and runs well, and the mileage is about as good as I expected this time of year. THis is a 1.6TD I took out of an 84 Jetta, 138,000 km. Bought the car as parts for an 84 gasser, was told the engine was junk. Story went like this. The owner got the car from his mother, put an oil pressure guage in, and thoughtthe pressure was too low. He rolled in a set of bearings and put in another oil pump (turns out from a junk gasser!).When he fired it up, it went from low to nothing. When I got the car home, I figured I'd check. I put a new oil filter on , filled the crank with oil, screwed a guage in the head. Engine fired easily, but I got no oil pressure reading. I pulled the pan and found that the oil pump had a loose screen, and had picked up a washer off a pan bolt that he had lost, and broke the pump. Promptly gave up on putting this in my 84!
Jump ahead a year, purchased a high mileage 92, already ringed once. Not having any experience with volks diesels, when the car ran okay after a pull start, no noises, but was hard to start, I figured glow plugs, maybe injection system. since I had a parts motor, I bought the car. When I started reading about these things and discovered bad compression as a likely cause, I bought a compression tester and got 260 lbs on #4, went bacj to the other motor. Pulled it out of the parts car, pulled all the main caps and rod caps, and decided that the other guy must have had all his problems in the drive and shut the car off in a hurry, No damage to the crank!!! I put a set of bearings and the right oil pump in the engine ,new water pump, and crank seals (just because it looked like it was a lot easier out of the car) checked the glow plugs (since I had the pump off to change from A1 to A2 mounts and change the air conditioning bracket to one with power steering)and put it in the car. Just lined everything up and put the belt on. I know the cam is retarded a little (should fix it) and am guessing from the way it runs that the pump could use a little advance too. Didn't want to play with anything until this motor that sat for several years has run for a few months. It started out using about a litre of oil in 1500 km for two or three litres, seems to have quit. I suspected crankase vents or turbo, because the rings are tight enough that it started at -22c on a windy day , not plugged in. Still working out a few bugs, but the car runs good! BTW the turbo is a Garret.
I like th pulley design. Reminds me of one I saw off the fuel pump of an older Cat truck motor. They have variable timing on the fly though. Timing changes with engine speed. counterweights and springs! ( and a lot more money!)
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I like th pulley design. Reminds me of one I saw off the fuel pump of an older Cat truck motor. They have variable timing on the fly though. Timing changes with engine speed. counterweights and springs! ( and a lot more money!)
I think someone on here posted a link for a pulley like that for gasser VW's. I know at one point someone made one, but it was expensive and I dont think it sold very well. Neat idea though, almost like VTEC or Vanos or something for 8v's. :P
Brendan
84 Scirocco 8v
00 Camaro L36 M49
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Hi forgive me for my ignorance; but what is the purpose of your adjustable sprocket?
It looks like it has a keyed parallel hole whilst the diesel has a tapered boss and although also keyholed its just pretend :wink:
If cam advance needed just slacken off nut an advance CS and pump. Then retighten.
At a loss as to where you are? then mark bolt head on cam; as this always tightens to same position relative to cam.(Using same torque...MAYBE) :?:
One gasser variable not available is ignition timing...Unless perhaps the laborious gasket shimming is undertaken...or...maybe a homemade design of a sparkplug in a glowplug body :twisted:
Mark(The Miser)UK
'87 TD Quantum
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What you really need is three studs with rack and pinions behind to move along your mm scale.
Mark(THe Miser)UK
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(http://www.diesel-speed-shop.com/images/culasse.jpg)
this is my special puley to fit gti came shft.
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Well, the "right" way to do it would be to put a degree wheel on the crank and measure valve opening with a dial indicator. If someone did this they could make some locking plates to make it fast an easy the next time. I personally don't see the need on an everyday driver, but if someone is going all out...............
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To set cam advance or retard precisely to desired specs, you could use the following method without any additional tools or parts required.
1. measure the diameter of the flywheel reference surface (the surface where the TDC mark is found.) I would guesstimate this is about 220-230mm or so (since the largest clutch disc OD is 210mm and it's got to be a little bit larger than that), but measure it on a flywheel to be sure and precise.
2. calculate how much distance at that circumference correlates to 1 degree of cam angle. 3.14159 x flywheel_reference_surface_diameter x 2 / 360 would give you the distance on the flywheel reference surface for 1 degree of cam movement.
3. set the cam to it's upright (TDC) position, lock it with the special tool that goes into the slotted edge of the camshaft with the feeler gauges, and loosen the bolt holding the pulley so that crank can be moved freely.
4. measure a deviation from the TDC mark equivalent to your desired advance (or retard) of the cam, in the desired direction (advance or retard.) If you wanted to make this step easy, you might be able to apply some "timing tape" or make marks on the flywheel, like they use on gasser engines to set spark timing with the strobe light.
5. tighten the cam pulley to specs (I believe 33 ft-lbs.)
Voila! Precise setting of cam advance or retard is achieved, without any special parts or tools. Problem - as has been stated on this thread already, these engines are very tight at TDC, as the piston gets very close to the valves at that point with normal cam timing. Varying the timing may be running the risk of piston-valve interference (which is no fun and will really ruin your day, believe me.)
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As a follow on to Jakes i/p; one could move the crank to the point where hand rotation of engine just catches valves. A nice big blood red splodge of paint at this point would show you how far you had left before engine death.... :twisted:
Mark(The Miser)UK
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To set cam advance or retard precisely to desired specs, you could use the following method without any additional tools or parts required.
1. measure the diameter of the flywheel reference surface (the surface where the TDC mark is found.) I would guesstimate this is about 220-230mm or so (since the largest clutch disc OD is 210mm and it's got to be a little bit larger than that), but measure it on a flywheel to be sure and precise.
2. calculate how much distance at that circumference correlates to 1 degree of cam angle. 3.14159 x flywheel_reference_surface_diameter x 2 / 360 would give you the distance on the flywheel reference surface for 1 degree of cam movement.
3. set the cam to it's upright (TDC) position, lock it with the special tool that goes into the slotted edge of the camshaft with the feeler gauges, and loosen the bolt holding the pulley so that crank can be moved freely.
4. measure a deviation from the TDC mark equivalent to your desired advance (or retard) of the cam, in the desired direction (advance or retard.) If you wanted to make this step easy, you might be able to apply some "timing tape" or make marks on the flywheel, like they use on gasser engines to set spark timing with the strobe light.
5. tighten the cam pulley to specs (I believe 33 ft-lbs.)
Voila! Precise setting of cam advance or retard is achieved, without any special parts or tools. Problem - as has been stated on this thread already, these engines are very tight at TDC, as the piston gets very close to the valves at that point with normal cam timing. Varying the timing may be running the risk of piston-valve interference (which is no fun and will really ruin your day, believe me.)
good , but on stock engine be careful ! valve and piston are verry ....
i've make a special puley because i use a gti cameshaft.
bigger lift and longest inlet and exhaust time, for very high boost.
the piston are modified for the valve secure space.
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I wondered if anyone was running gasser cams in the diesels. Opens up all kinds of options! Guess I have to pull the Chilton's manual out tomorrow to read up on cam specs. Let me see, 1.9, 1.6NA, 1.6TD, 1.7 gas, 1.8 gas, 2.0 gas, GTI's, etc., etc., etc.,...................
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Cool pulley, Caddy. Do you sell those? ;)
Also, with your piston modifications, how much deeper of a cut do you make to the piston for the gti cam to work? This is of much interest to me, since I happen to have a complete 1.8 solid lifter engine sitting in my Rocco, complete with stock "W" camshaft. ;)
If I do have to use a 1.6, it will have as much 'hot' parts in it that I can scavenge. :D
Thanks-
Brendan
84 Scirocco 8v
00 Camaro L36 M49
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(http://www.diesel-speed-shop.com/images/culasse.jpg)
this is my special puley to fit gti came shft.
what parts did you use? the inside from the gti pulley and the outside from a diesel?
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I played with advancing cams and stuff, never found much gain, fitting a gti cam is a lot of work. Your best bet would be my custom cams :twisted:
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I played with advancing cams and stuff, never found much gain, fitting a gti cam is a lot of work. Your best bet would be my custom cams
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plug!! hehe. or my hid conversion kit! :lol: :wink:
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Yeah sorry about that haha. I hear your HID kits add like 20WHP and increase turbo spool up and decrease EGTS :D
Sorry I just wanted to point out that you can have a custom ground cam shaft so you don;t have to modify you pully or pistons and still get a performance increase.
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As a followup to Jake's post. Count the teeth on a spare flywheel and divide by 360 to find teeth/degree.
Andrew
I did this a few years ago. I advanced the cam 4 degrees and it really woke up my engine. It was just shortly after that that I discovered that my valve clearance was total junk (some valves had zero clearance with the thinnest shim) and so I got a new head. It's been at stock timing ever since because I now have plenty of power and don't feel any need to mess with it.
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935 racer when is a stage 3 camshaft or a full blown race cam coming out?
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stage 3 is out and done, I'm not going any further with cam developement for the IDI engines until I start selling more. I just sent andy2 a stage 3 for his twin setup :twisted:
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i'd be interested possibly in custom grinds... for the mTDI project, but as far as sharing info goes it'd be nice to see "how" these are performing on the cars themselves. Custom grinds for diesels have been done before, a few even for the TDI in Europe and the gains vs. the trade off of losing low end torque turned out to really not be worth it. Any info on the performance of your cams specifically 935racer... think I asked that before when I was telling you about the 4bt pump and it never got answered. Even have an extra couple cams sitting here too :) 1 TDI spare and a couple IDI units...
Joe
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I have done some work on a TDI cam, both from benchmarking existing OEM cams as well as some aftermarket offerings with known specs.
http://forums.tdiclub.com/showthread.php?t=123951&highlight=cam
http://forums.tdiclub.com/showthread.php?t=108233&highlight=cam
The result was that I had a small run of 5 cams made some months ago, and I'm eager to hear how they work on the cars of the customers as spring draws near.
One is already installed in Gerry's (DIESEL DAZZLER) HOT Caddy TDI (http://forums.tdiclub.com/showthread.php?t=106903). Gerry set a 1/4-mile trap speed last year of 112.99 MPH, but traction hampered his E/Ts and he blew the turbo 2/3s of the way down the track on his best (and obviously last) E/T of the day with 14.511 (http://forums.tdiclub.com/showthread.php?t=113474).
This year, we're aiming for 240 HP from the TDI with a hybrid VNT turbo from a Dodge Sprinter CDI, phat hole injectors, 12mm pump, cam and custom programming. Being able to extend the useable RPM range to 5500 RPM or so will really help E/Ts since a shift into 5th might be dispensed with. I have a feeling we are going to see 12s this year, if not in North America then in the U.K. There is a feverish competition going to to have the first documented 12-second TDI with only Diesel (i.e. no methanol or propane injection) and no giggles. Gerry's Caddy is 2200# loaded with driver, so you can imagine what that, slicks and 240 HP can do...
There is a planned dyno day at a state-of-the-art facility in London with an eddy-current unit sometime in April. You guys in the area should attend. :)
Edited to correct typo on trap speed.
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Even have an extra couple cams sitting here too :) 1 TDI spare and a couple IDI units...
Even if you don't decide to put in a reground cam, the AAZ cam has a little more duration than the TDI cam. This alone would be worth for the small effort to install into your M-TDI if you already have the cam.
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Hopefully My 18.5:1 compound (K24/hx30) AAZ will be ready for then,as I may not only attend the Dyno day :D .I was making somthing like 160-165 hp when I bent the rods with 37 psi on 21:1, Also on #2 only(no drugs yet :lol: ).With the Passenger Preformance stage 3 cam,12mm head and big FMIC to work with this time it should be very interesting.Not trying to say I'll be up there with Gerrys TDI,only that the IDI won't be too far behind.
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Have you been able to come across any maps of the Holset turbos? I can't seem to find any without resorting to pay-for sites. Infuriating, really, when opportunists like that don't have to pay Holset to get a hold of maps...
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Even have an extra couple cams sitting here too :) 1 TDI spare and a couple IDI units...
Even if you don't decide to put in a reground cam, the AAZ cam has a little more duration than the TDI cam. This alone would be worth for the small effort to install into your M-TDI if you already have the cam.
Only have the 1.6 IDI cam and my spare TDI unit...no AAZ units around...though, if someone has one they'd like to sell to the cause...i may be willing to try :)
I remember reading about your cams on TDI club... quite impressive...can't wait to see the results. They were drawn from blanks too weren't they? Not just the regrinds like some are offering...
Joe
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From what I understand, the 1.6 cams will not swap over to the AAZ/1Z/AHU...
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Havn't come across any Hx30 maps either only HY/Hx35 ones I think.The sprinter CDI is only a 2.5 or is it 2.7L,do you think mabye its still not big enough for the amount of power you'll be at?The HX30w I'm using comes of a 3.9L cummins it makes up to 150 hp stock I believe.I'd imagine the EGT's/backpressure would still be through the roof when using the CDI turbo.If Gerry had a quick reacting thermocouple(not VDO) and mounted Pre turbo I think he'd be shocked at the EGT's even with that turbo,I'm definitely no expert though, only commenting as I've taken numerous pre turbo pressure readings while playing around with different turbos for my setup.It takes a pretty big turbine to flow 150+hp at 35-40psi properly.What boost levels are you guys wanting for 240hp on the TDI?
BTW RabbitGTDguy the 1.6td hyd cam is almost identical to the aaz cam.
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I would greatly appreciate it if you could post or otherwise somehow share the HX35 maps that you have. Seems really hard to come by... There are envelop maps out there but they don't give the depth of data I like...
I don't think an even bigger turbo nor compounding is in the cards, but that's Gerry's call, not mine. Even with crazy fuelling, there's light to moderate smoke with 20 PSI of boost. A single stage GT22V is operating near peak efficiency at about 1.9 bar of boost (approx. 28 PSI). If VW Motorsports' race TDI can be used as a template (and a very good one at that), I'd say we can easily meet the 240 HP goal on 28 PSI quite smoke free and less stress on the bottom end...
Gerry does have an EGT gauge, but not pressure transducer. As for this thing about EGTs, etc., being affected by turbo size, I've spent exhausting years trying to debunk that myth. But I confess it all depends on what one is looking to get out of the turbo. If maximum, unadulterated HP is desired, with no consideration for spool and low-RPM driveability, sure go with a massive turbo or two.
I seem to go against the grain and advocate what I should call the "Goldilocks" approach to have a "right-sized" turbo for the engine's breathing capability and power output, and I also would rather choose a VNT turbo over a WG unit any day. But I guess being the unfortunate combination of a perfectionist engineer with an eye for hard numbers rather than intuition, and being an efficiency freak, puts me at odds against the tide...
A thread worth reading on the subject:
http://forums.tdiclub.com/showthread.php?t=130109
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when is dyno day? Maybe ill show up! :twisted:
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I have a 1.6 cam in my 1.9 AAZ head. Works fine.
12mm pump, cam and custom programming. Being able to extend the useable RPM range to 5500 RPM or so.
I'm curious as to know how you or Gerry will overcome the RPM limitation with the 12mm pump. Many people are afraid to go over 4,500 RPM with 12mm. Even Jeff @ Rocketchip avoided going above 4,000 RPM on a dyno with his 12mm.
Secondly, for 5,500 or above ("or so", as you put it), what is his solution for timing advance?
In the TDIclub.com thread you posted, you mentioned that a Porsche has a VNT. IIRC it is VGT. They both have the same concept but not the same technically.
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Some stuff about compound turbocharging that i'm sure Tdimiester is well aware of. :wink:
Mark, I think you just jumped in over your head... :lol:
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Mark, I think you just jumped in over your head... :lol:
Yes I did.. I just skimmed through a few posts and then typed too quickly :oops: I edited my post to remove the pointless bit.
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Mark, I think you just jumped in over your head... :lol:
Yes I did.. I just skimmed through a few posts and then typed too quickly :oops: I edited my post to remove the pointless bit.
Hey, thats what friends are for. :wink:
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I have a 1.6 cam in my 1.9 AAZ head. Works fine.
OK, my bad. I was going from second-hand information from somewhere I don't remember that someone had tried to fit a cam from an ME into a TDI. The AAZ and 1Z/AHU swap nicely, but IIRC the was some issue over fitting the ME cam into the TDI. I must have mixed something up... maybe the issue was over valve-to-piston clearance...
I'm curious as to know how you or Gerry will overcome the RPM limitation with the 12mm pump. Many people are afraid to go over 4,500 RPM with 12mm. Even Jeff @ Rocketchip avoided going above 4,000 RPM on a dyno with his 12mm
Secondly, for 5,500 or above ("or so", as you put it), what is his solution for timing advance?
To be honest, the 12mm pump bit is my little contribution... I got a brand new AHU pump a while ago, and sent it to Marc to install a 12mm head kit into it. It is still sitting in Gerry's garage and I'm hoping it gets some use because it's a lot of money being tied up doing nothing...
At the moment, Gerry's truck has a bit of a Frankenstein pump with AHU pump body, 11mm plunger and solenoid portion from an ALH to be compatible with the 98 New Beetle wiring harness and ECU that is being used.
We don't really know what the 12mm pump will do much over 4,000 RPM, but several Europeans (Stefan @ Digital Racing, TDIFreak in Finland, etc.) are running 12mm pumps and don't report problems up to the TDI's conventional redline... I seem to be more keen on the 12mm than Gerry but to answer your question, Gerry's truck is running an 11mm and a 12mm just waiting to be used.
As for timing advance, Gerry and I have met with Jeff @ Rocketchip several times since Waterfest 2004 and he has shown us his pump mod in the timing control collar to allow greater advance. Gerry is in the process to do that mod over this winter.
In the TDIclub.com thread you posted, you mentioned that a Porsche has a VNT. IIRC it is VGT. They both have the same concept but not the same technically.
From what I have seen of pictures, the BorgWarner turbo still uses guide vanes in the turbine, just like Garrett. The adjustment mechanism might be different though... Some years ago Garrett won a patent infringement case against BW and an injunction on BW's KP39. BW was forced to change the design so that it did not infringe, but I don't know the details. I think VTG is just BW's way of calling more or less the same technology as Garrett's VNT. Holset variable turbos use a completely different mechanism that looks like a big single swinging arm in the turbine. The Porsche turbo definitely doesn't use this from the pictures I have seen. Guide vanes are nothing really new. They are used almost universally in gas turbines, and many of the same technologies for gas turbines trickle into turbocharger designs.
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when is dyno day? Maybe ill show up! :twisted:
Date not confirmed yet but here is the thread you can follow up:
http://forums.tdiclub.com/showthread.php?t=128725
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Custom grinds for diesels have been done before, a few even for the TDI in Europe and the gains vs. the trade off of losing low end torque turned out to really not be worth it.
Most of the European TDI cams I've looked at (Dbilas, Piper, Sorg) are also regrinds and while I won't confirm or question their HP claims (approx. 15 HP), I found many of them to have way too much duration... One cam in my database advertises 272 degrees of duration at the intake, most are north of 250 degrees at lash). This on an engine that redlines at 5100 RPM fer cryin out loud!
I deliberately kept the duration conservative at 209/204 @ .050. It's not flashy and won't give "paper" gains north of 6000 RPM :roll:. It softens the bottom end a touch, but hey, everything's a compromise, right; it depends on what individual's priorities are. I tried to preserve the low-end as much as possible while targeting better breathing at a realistic upper limit of the TDI's rev range, meaning upto 5250 RPM.
I think as much is gained through the higher lift than stock about (1.5mm more) than the extra duration...
There, you know basically everything about the cams, but I reserve to hold on to the precise timings and lifts, etc., until I see some numbers to validate my predictions (or not). Copy it if you want to try. I have better things lined up. ;) :)[/list]
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OK, my bad. I was going from second-hand information from somewhere I don't remember that someone had tried to fit a cam from an ME into a TDI. The AAZ and 1Z/AHU swap nicely, but IIRC the was some issue over fitting the ME cam into the TDI. I must have mixed something up... maybe the issue was over valve-to-piston clearance...
I think the the fitment problem is with the locking tool/vacuum pump drive slot on the ALH TDI. Previous diesels have this slot machined about 4mm off centre so the locking tool lies flat on the head surface. I beleive the ALH slot is closer to being centred.
All previous diesel cams, all the way back to the 1.5 and 1.6 solid lifter engines will happily interchange. I know of at least one person that ran a 1.6 cam in his AHU TDI for a while.
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I'm going to try to dig out cam specs on the respective units tonight. It'd be nice to see what the different units may have to offer ...
Joe
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I'd be interested to know too. I have a little database with some OE VW gas and Diesel cams. One the Diesel side, I only have AAZ, SDI and TDI cam specs, but none from the earlier 1.5/1.6 Diesels.
Another member on both forums, SpikeTDI, had done some investigations and simulation using the same software as me. He had come up with a cam profile that looked very good, but I have not succeded in getting in touch with him.
(http://pics.tdiclub.com/data/500/18482CUSTOM_GRINDS_TDI_SDI_AAZ_CU7.jpg)
Discussion thread here (http://forums.tdiclub.com/showthread.php?t=86517).
I would like for him to run an analysis of his cam using the same baseline engine file I developed here (http://forums.tdiclub.com/showthread.php?t=123951).
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Some more good discussions here:
http://forums.tdiclub.com/showthread.php?t=84939
http://forums.tdiclub.com/showthread.php?t=13734
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We don't really know what the 12mm pump will do much over 4,000 RPM, but several Europeans (Stefan @ Digital Racing, TDIFreak in Finland, etc.) are running 12mm pumps and don't report problems up to the TDI's conventional redline... I seem to be more keen on the 12mm than Gerry but to answer your question, Gerry's truck is running an 11mm and a 12mm just waiting to be used.
The general consensus at tdiclub.com (for what it's worth) is that the 11mm is ok up to 5,500 RPM. Beyond that, maybe. The 12mm according to Bosch info max out at 2,100 RPM, give or take 100 RPM.. approx. 4,400 RPM crank. Some people may push it a little further, but 5,500 RPM crank is quite out there.
I have 10mm (stock IDI = 9mm), 11mm, and 12mm parts... I was only curious as to know if Gerry has overcome the low-RPM issue with 12mm. My pump will be tested on a Bosch dyno at a pump shop so we'll see how it goes with each upgrade. For the record, my pump must be built for max. 3,500 RPM (7,000 RPM crank).
As for timing advance, Gerry and I have met with Jeff @ Rocketchip several times since Waterfest 2004 and he has shown us his pump mod in the timing control collar to allow greater advance. Gerry is in the process to do that mod over this winter.
Do you know how many degrees advance?
I vaguely recall in 2004 that Jeff was interested in building a revver TDI (I could be wrong.. I did talk with him about making my ALH TDI rev high), but it looks like he has max. 4,000-4,500 RPM with 12mm pump today, which makes his pump timing advance mod seem obsolete, just for his application.
Another member on both forums, SpikeTDI, had done some investigations and simulation using the same software as me. He had come up with a cam profile that looked very good, but I have not succeded in getting in touch with him.
He has been spending more time in the hospital than out lately.
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The general consensus at tdiclub.com (for what it's worth) is that the 11mm is ok up to 5,500 RPM. Beyond that, maybe. The 12mm according to Bosch info max out at 2,100 RPM, give or take 100 RPM.. approx. 4,400 RPM crank. Some people may push it a little further, but 5,500 RPM crank is quite out there.
I have 10mm (stock IDI = 9mm), 11mm, and 12mm parts... I was only curious as to know if Gerry has overcome the low-RPM issue with 12mm. My pump will be tested on a Bosch dyno at a pump shop so we'll see how it goes with each upgrade. For the record, my pump must be built for max. 3,500 RPM (7,000 RPM crank).
As for timing advance, Gerry and I have met with Jeff @ Rocketchip several times since Waterfest 2004 and he has shown us his pump mod in the timing control collar to allow greater advance. Gerry is in the process to do that mod over this winter.
Do you know how many degrees advance?
I received this PM from Gerry just a few hours ago:
HI Dave I got the motor out and the 22 back on with my new intake.Modified the pump so it gets more advance.
I cut the top off a IZ manifold and welded on 3 inch tube with a slot in the tube to match the manifold,inlet on the end.
Planning on tearing down the trans soon and getting a diff from JRP.
Got a electric FP that I want to hook up too.
Got to find some slicks too.
Still working on a better boost control, I think i should open up the vanes some more on the 22 to keep the speed down.
As I recall (and this is going strictly from memory, so take it FWIW), you hit the stop on the timing collar at about 27 degs. Jeff showed us how we can through some machining increase this to about 35 degs. Don't know where this will take us in terms of RPM potential. Obviously programming will have to play along, and I don't know what is the limit that the ECU can address...
I vaguely recall in 2004 that Jeff was interested in building a revver TDI (I could be wrong.. I did talk with him about making my ALH TDI rev high), but it looks like he has max. 4,000-4,500 RPM with 12mm pump today, which makes his pump timing advance mod seem obsolete, just for his application.
Another member on both forums, SpikeTDI, had done some investigations and simulation using the same software as me. He had come up with a cam profile that looked very good, but I have not succeded in getting in touch with him.
He has been spending more time in the hospital than out lately.
I'm very sorry to hear that. We have had some good discussions (and arguments) off-line and on (almost in that order, respectively...) I hope he gets better from whatever ails him. If you or anyone else reading this are in contact with him, please send him my best regards.
Dave