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#165 by 935racer on 15 Dec, 2005 19:30
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That tractor is badass. But really it is amazing how much airflow there is now compared to when the stock 1.6 head was on. I'll get some #'s once I get my flowbench all together.
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#166 by malone on 16 Dec, 2005 01:22
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Brett's picture above is more realistic re: my TD until it blew
The smoke in the pic I posted is a bit too dense. Nice tractor pic btw.
If heating the intake with a heat gun helps then this is the permanent setup I may try: a few glow plugs drilled into the pipe just before the intake.
The 3 red thingies represent 3 glow plugs. It doesn't have to be VW Bosch, it can be whatever will spread heat well. Just need to drill holes into the racepipe and then screw in the glow plugs. Extremely easy to install and extremely easy to replace/maintain, not to mention inexpensive. Depending on the number of glow plugs, the pipe will resemble an airplane radial engine
. It may reduce the need for glow plugs in the TD head, which take longer to test & replace.
The custom low RPM switch for plugs is an ideal solution, but for now I can use the factory switch on the fuel pump bracket.. it's used for the shiftlight indicator on factory instrument clusters. I can wire the no-throttle switch (opposite of WOT switch) to the glow plugs...voila, done in 5 minutes. During no throttle (e.g. @ idle) glow plugs are turned on. As soon as I touch the throttle to accelerate the car, the glow plugs will turn off immediately and the prechamber/cylinder probably won't cool down too quickly as more fuel are immediately injected.
This may be a nice progress. The EGR throttle plate & higher temp thermostat are still considered as well. -
#167 by VWRacer on 16 Dec, 2005 07:00
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Mark, if you are going to this much trouble, why not simply wire the main glow plugs to do this? Even easier, I'd think, and keeps the heat where you need it.
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#168 by malone on 16 Dec, 2005 07:36
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Quote from: "VWRacer"
Mark, if you are going to this much trouble, why not simply wire the main glow plugs to do this? Even easier, I'd think, and keeps the heat where you need it.
A few reasons:
1) Using the main glow plugs alone cuts down smoke almost completely @ idle, but not while revving the engine in neutral, which resulted in a fail at Aircare.
2) Using both sets of glow plugs @ head & intake may show improvements. It could also result in smoother Winter starts.
Glow plugs in the "race pipe" before the intake won't be high maintenance. If I want to get rid of the plugs completely, I can simply replace the racepipe with another pipe that has no holes. This requires loosening of just 4 bolts or nuts. The only negative thing I see in installing glow plugs in the intake is potential turbulence of charge air travelling around the plugs but I don't think it'd be a big issue. Anyway it'll be an inexpensive experiment. One small thing at a time. -
#169 by fspGTD on 16 Dec, 2005 10:10
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Mark, not a bad idea at all, but I would think you might get better results using a heater designed for this kind of application instead of glow plugs... I'd look into grid heaters found in some (usually direct injection) diesel's cold starting systems.
The problem with using a glow plug here is that you can be assured the heat will be utilized far less efficiently than mounted in the head, because of how far away it is in both distance and timing from the fuel injection event (so it might not help very much.)
FYI - I don't know a whole lot about DI diesel grid heaters, but a quick web search uncovered a few data points: I found references to 400, 600, and 1000 watt models being added or OEM on some light-duty truck DI diesel motors. I coudn't find a picture of what the heating element of one looks like, but this page has a picture of what one looks like on the outside (scroll down a little bit past the center): http://www.thedieselpage.com/features/2006MY.htm
Also, be careful about overloading your alternator. Ideally you'd want it to be able to "keep up" at idle and not draw your battery down. You are talking about adding a lot of additional electric current draw here that will possibly be used frequently and for long cycles. Even a 500 watt model would be 46 amps current draw :shock: Alternators often can only put out a fraction of what they're rated at idle by the way. I've got a picture of current versus RPM of an automotive type application unit somewhere that might help illustrate this. You might want to rethink going all out on the electrical heating.
If it were me I'd try a warmer thermostat first. :wink:
Some VE pump throttle arms (like I think on some RA, SB, or 1.9 TD engines) have the throttle pedal isolated from the governor input shaft, and they're connected with a spring and a damper. This slows the reaction of the pump to the throttle pedal. Although it's not the hot ticket for a quickly responding engine, you might not need the precise throttle response for your application. It might prove useful for keeping your motor from missing during the "snap throttle" emissions test. Or you could just defueling the pump for the test and then re-set it how you want it afterwards.
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#170 by malone on 16 Dec, 2005 14:41
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I have no stereo system in my car, just interior & exterior lights, glow plugs, and occasionally the vent fan. That's still a lot of current draw for a grid heater though!
Again, thanks for the very informative posts, I'm consuming them.
Roger on doing the thermostat swap first. I'll also wire the no-throttle switch (on fuel pump) to the main glow plugs tomorrow. I have a question: The factory wires embedded into the switch appear to be 18 gauge, is that too small for glow plugs?
My idle water temp is actually 180 degrees F (82 C). It occasionally rises to 185 while driving. If I leave the interior heat on full blast during idle the water temp may even drop below 180 degrees F. That doesnt' happen anymore after approx. 20 min of driving, I assume due to increased oil temp. Would a 194 F (90 C) thermostat be a good choice?
Cheers,
Mark -
#171 by fspGTD on 16 Dec, 2005 15:26
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It is a lot of current draw... and it would be even higher combined with glow plugs being on at the same time! :shock: According to Bentley, four factory A1 diesel glow plugs initially draw 140 amps when they're switched on cold, and then the current drops down to a steady 36 amps. The newer bosch duraterm plugs might drop that current down even more during extended glowing however.
The following alternator "dyno plot" showing current output capability versus RPM is typical for automotive street application alternators:
This explains why on some cars the voltage easily sags at idle.
I really doubt the light-duty throttle switch would hold up to glow plug current. You could always just wire in a heavy duty relay in parallel with the stock (timed) glow plug relay. It could be controlled by the VE pump electrical shut off solenoid +12v signal routed through the throttle switch maybe. Or perhaps the stock glow plug relay could be triggered if not directly controlled by the throttle switch.
Factory thermostat temperature for both an '84 Rabbit turbo-diesel or a 2001 Golf TDI is 87 deg C - 102 deg. C according to ETKA. So a thermostat that starts opening at 87 deg C shouldn't give you any major problems with overheating and boiling over if you've got a healthy cooling system I wouldn't think. Although I'm not sure if thermostats are readily available much hotter than that, a little bit hotter might work even better for your application if you could keep the coolant from boiling. You might need to also change radiator fan switches if you find your radiator fans were on all the time with the hotter thermostat.
The VW "blue" coolant was introduced to run at a higher temperature without boiling by the way than the old "green" stuff, so that might give a little added protection against boilover with running the engine hotter. Not sure how the boiling point of vw's latest "pink" coolant compares though. More glycol and less water can raise the boiling point, as can running a higher system pressure (I found some specifics in the middle of this web page:
http://www.are.com.au/feat/techtalk/coolants.htm )
So also increasing the pressure of your expansion chamber cap would make your system more resistant to boilover. Although the extra pressure is harder in the rubber hoses, etc. I'm pretty sure the stock VW pressure caps release at about 20psi. -
#172 by malone on 16 Dec, 2005 18:10
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I'm still running green coolant but will switch when I swap thermostats. I bought a jug of VW pink coolant a while ago that I'll use - will look up its boiling point.
My MK3 coolant reservoir had to be replaced 2 times due to boil-over from WOT pulls with LDA active. Once it leaks through one of the small ports on the reservoir (not through the pressure cap, which hasn't happened at all) it is irreversible - it will continue leaking even when the coolant's mildly warm. Maybe my cap's on too tight or is defective.
The VR6 radiator I installed seems to do a better job in stabilizing the coolant temp. My old 1.8L 8v radiator was even smaller than a 2.0L 8v radiator! I haven't seen over 195 degrees F lately, but I haven't driven with the LDA active lately either, I prefer to wait until intercooling is in effect.
What is the burn point / amp rating for the OEM glow plug fuse? I currently don't have a glow plug fuse (didn't come with for the swap) but I would like to buy a modern fuse with the same burn point. I had a Golf/Jetta II Bentley that's currently in 935racer's shop... not sure if it has detailed information on the fuse - will check tmw.
Cheers, -
#173 by deepmud on 16 Dec, 2005 19:06
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look into Evan's if you want to try xtra high coolant temps - it's boiling point is 375 at sea level. It's not as good at tranferring heat as glycol/water, but if you are trying to keep the combustion chamber hotter, so much the better. One of it's good point in hight temp is that it tends not to form steam pockets at the super-hot points in the cooling system, namely in the cylinder head, so even with say a spot-temp of 300f it keeps cooling effectively, whereas a pressurized glycol mix with a boiling point of 245 or so will have formed a steam pocket there - steam cools really poorly, and temps in localized spots can run away to severe damage territory really quickly. Also,with no steam pockets, no water vapor/bubbles in the coolant stream, in the radiator, etc.
It's different stuff, and usually will require an upgraded cooling system (bigger radiator) for warm climates. Some interesting testimonials on their site, including running some earthmoving equipment at high altitude in China - high altitude effects pressurized cooling systems all the more.
One of my friends with a 1.9td in Colorado has had troubles with overheating in his converted Suzuki - it seems fine on shorter trips, but long hills at altitude have cause boil-over 3 times. It may be too late, but I wanted him to give Evan's a shot. So far, he just plans to be ready to rebuild it :?
I think I'll swap over to it next summer when I am on the road again - my rig tended to run hot as well. It works the motor pretty hard and at high rpm to push my large-tires-and-boxshape down the road.
oh - and as far as corrosion resistance, it's supposed to be an electrical insulator - no corrosion.
http://www.evanscooling.com/index2.html -
#174 by VWRacer on 17 Dec, 2005 05:02
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Quote from: "DVST8R"
The deck mod probably adds 5cc - 7cc of volume per cylinder. I dont recall if we mesured it. It is used on the PDR race trucks as well as on some gas engine's it was originoly pioneered by a guy in India, he clamied that on a gas motor it made it almost direct drive, no need for a tranny as the torque spread was so good.
I think I remember reading about this guy in India. Anyone have a link? -
#175 by fspGTD on 17 Dec, 2005 11:55
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I just wanted to point out that Mark if you can beat the 188 crank hp mark in a 1.6l liter displacement diesel, you've beaten the specific power output of the brand new, yet to be raced even V12 TDI lemans car!
Imagine, us grassroots, ameteur-funded DIY'ers beating VW/Audi motorports with all their millions in resources...
Check out what this guy said about the brand new V12 TDI in the Lemans racer:
“This engine is the specifically most powerful diesel there is in the world and, up until now, the biggest challenge that Audi Sport has ever faced in its long history,” explains Ulrich Baretzky, Head of Engine Technology at Audi Sport.
http://www.autoblog.com/entry/1234000250072361/
The displacement (5.5 liters) and hp numbers ("exceeding 650hp) are stated elsewhere in the article. Do the math to figure out what hp a 1.6 liter diesel would need to get to match the specific power of this motor, and you will find it's "only" 188hp.
If you can develop an engine even close to this number while making it also daily driveable, I'd say that you should deserve a big medal.
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#176 by 935racer on 17 Dec, 2005 12:59
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Big medal for 188, no worries man its going over 200WHP all in good time. :twisted:
P.S. I built the motor :wink: -
#177 by DVST8R on 17 Dec, 2005 21:13
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"Most powerfull Diesel engine in the world"... as compared to what?... race "car's"
I have ridden in a dodge with more dyno, and track proven hp then that. As well I have witnesed several dyno's of trucks pulling over 800whp. It would be approx. 700hp to be equivelnt hp/L, for a cummins 5.9L. Don't even get me started into pulling tractor's...
I'm sure Marks motor will get there, its just a matter of $$$.
In there defence I don't think Marks motor would survive a 24hr race though. :wink: -
#178 by Kudagra on 17 Dec, 2005 22:56
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Quote from: "fspGTD" I'd look into grid heaters found in some (usually direct injection) diesel's cold starting systems. :P
[/quote
Bobcat skid steer loaders with the 3300 Kubota diesels have those grids. Ill keep my eye out for one. -
#179 by jackbombay on 18 Dec, 2005 01:13
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Quote from: "DVST8R"
In there defence I don't think Marks motor would survive a 24hr race though. :wink:
The race car MUST also make that HP smoke free :shock: