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  #11  
Old 05-01-2012, 04:48 PM
FJ40Jim FJ40Jim is offline
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I like the idea of using the manual timing advance vs. the thermo widget.

I have a rabbit pump on a shelf, and a complete D24T engine on a stand. If there is anything I can take a pic of or compare between the two, LMK.
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  #12  
Old 05-02-2012, 04:47 AM
piper109 piper109 is offline
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Hi George,

I had assumed that the Bosch engineers had chosen to keep things consistent from pump to pump.....silly me I should have known better!
Clearly your VE knowledge is way ahead of mine and thank you for applying the correction. Your explanation is very cohesive and easy to follow.

Are you in Europe for vacation reasons or VW reasons? Either way, enjoy the food and liquid refreshment. Just pretend that 1 Euro = 1 dollar, unless you are in UK of course. A well lubed pub lunch will dull the pain :-)

Cheers, Steve

Quote:
Originally Posted by v8volvo View Post
Steve,

My understanding of the difference between the VE pumps on the D24T vs the 1.6 is a little different. You're right that the D24T setup is under tension where the 1.6 setup is not. However, if I've got it right, that difference is not the result of a big spring applying return force, but rather a function of the location and action of the cold start advance lever.

To my recollection from the last time I had one apart: in the Volvo pump, the lever moves a ball stud on the inside of the pump housing. The ball stud directly contacts one of the "rungs" of the roller cage, moving the cage and rollers however many degrees to effect a timing advance. The Volvo has the CS advance lever mounted on the side of the pump body, and it has minimal mechanical advantage on the roller cage -- that is, for timing advance to take effect the lever moves only a short distance (maybe 15-30 degrees at the most) and with considerable force required. Probably the reason for that short travel range is due to the coinstraints imposed by the limited distance that the wax thermostat is able to move. I believe the high force required to move the Volvo pump's CS lever is a result of the force necessary to move the roller cage w/o much leverage. The external spring is fairly lightweight. (You can remove this spring and you will see that it is still not much easier to actuate the lever.) I think the spring is there mostly for the health and longevity of the CS cable and rest of the mechanism, so that there would be something to pull the lever all the way back against its external sheetmetal stop tab after the lever's internal ball stud backs off from contacting the roller cage.

The VW 1.6 pumps, if my assessment is correct, use quite a different system. The cold start lever is located lower in the body on a Rabbit pump, down in the area of the dynamic advance piston. (In the same location where, on a D24T pump through 1984, there is just a diamond-shaped cover plate, and on 1985+ cars the high altitude compensation advance solenoid is located.) The lever on those pumps moves a much greater distance with much less force -- the difference between advanced and normal positions on a Rabbit, for instance, is almost 90 degrees, and there is a detent at the end of the lever travel that the Volvo pumps don't have. My suspicion is that the advance mechanism in these Rabbit pumps works on a sort of screw principle where the lever's rotational movement horizontally displaces the advance piston in the bottom of the pump, and physically shifts the whole dynamic advance system (and roller cage) that way.

Basically to my understanding it's just two ways of skinning the cat, but with differences -- one which is tailored to operation by human fingers working through a plastic knob and skinny Bowden cable, and the other which is better suited to big mechanical forces applied by fair size springs and a much heftier cable. I believe it would be possible to convert a Volvo pump to use the 4cyl-style manual advance system, but probably the existing advance setup would need to be removed and covered with a side cover plate, and then a manual advance mechanism from a Rabbit or similar would have to be installed in the bottom of the Volvo pump. Or alternatively, a custom pump could simply be built using Volvo internals, aneroid, and head in a Rabbit pump case.

Hope my ramblings are making sense, as I write from Europe with jet lag... I will see if I can find some pictures to demonstrate.

George
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  #13  
Old 05-04-2012, 02:02 AM
ian2000t ian2000t is offline
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Tried the new waxstat in a housing last night on the hob. Only took it to 70C so not to overheat it, and it extended about 20mm I think, then retracted when cool.

First time I have EVER seen one of these move lol!!! Now the fun part of putting it back on the car, and bleeding the air out of the top hose.
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1990 Volvo 765 D24Tic (factory UK spec Tic). Monark 273 nozzles 163bar, Ajusa MLS gasket, 16psi, Water Injection, 17" Titans with 25mm H&R spacers, running 85% WVO/SVO.
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  #14  
Old 05-04-2012, 03:38 AM
piper109 piper109 is offline
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Its not fun putting that thing together with the big spring. I have found it to be much easier with two long bolts that you take back out and replace with the correct ones 1 at a time. Mind those knuckles !

Steve
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  #15  
Old 05-04-2012, 04:42 AM
ian2000t ian2000t is offline
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Yep, will try that method if I have some bolts with the right thread (most of mine are UNF though).

Failing that, I'll empty the swear jar ready!!
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1990 Volvo 765 D24Tic (factory UK spec Tic). Monark 273 nozzles 163bar, Ajusa MLS gasket, 16psi, Water Injection, 17" Titans with 25mm H&R spacers, running 85% WVO/SVO.
http://i103.photobucket.com/albums/m...AG0269-sig.jpg
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  #16  
Old 05-04-2012, 11:00 PM
v8volvo v8volvo is offline
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If you have access to a spare injection pump (even one off a different engine, i.e. 1.6L VW diesel, older TDI, etc), the pump head screws (the ones that hold the iron pump head onto the aluminum body) are the same thread as the cold start thermostat housing screws, but longer. They can help to get the process started of putting it back together.

Or better yet, if you haven't taken your existing CS housing apart yet already, there is a method that member ngoma devised and showed me that is the easiest of all. Before starting to loosen any screws, can pick up a set of small needle-nose vise grips (locking pliers), pull the rubber accordion boot forward off of its position at the point where the cable exits the housing, and clamp your vise grips onto the cable there to prevent it from receding back into the housing as you take the screws out. This way the springs stay compressed even while you have the rear part of the housing removed, so that you can put it back together with ease. The only tricky part with this method is working around the pair of pliers that are sticking out and running into your wrench.... but that is still easier than fighting those springs on reassembly.

Getting the threaded gland nut thing that holds the thermostat unit inside its case is also a little tricky esp if it is stuck.... hammer and screwdriver with the housing in a vise is one method though fairly brutal. I have been meaning to make a proper tool by modifying an old socket, which is probably the better method... could grind away the sides of the socket until it is just a cylinder with two fat tabs sticking out to engage the slots in the CS t-stat gland nut, and then wind it right out.
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  #17  
Old 05-05-2012, 12:22 AM
ian2000t ian2000t is offline
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Guys thanks for all your help!

Yes, was good fun getting the waxstat out of the housing - hammer, screw driver and gave the housing some heat on the pan first.

Cold start is now finally on the car. I actually used a slightly different method but similar in principle.

Did as in pic 2 in this thread - put one of the wire screw connector blocks on the the cable before taking it apart. Dane as your pliers idea but easier to work around.

So all fitted now, so not knocking the crap out of my warm engine anymore. Does feel a bit slower in lower revs though - maybe static timing would like to be a bit more advanced? Think its on 0.96mm. But running veggy which burns slower than dino fuel.
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1990 Volvo 765 D24Tic (factory UK spec Tic). Monark 273 nozzles 163bar, Ajusa MLS gasket, 16psi, Water Injection, 17" Titans with 25mm H&R spacers, running 85% WVO/SVO.
http://i103.photobucket.com/albums/m...AG0269-sig.jpg
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  #18  
Old 05-06-2012, 11:12 AM
ngoma ngoma is offline
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Quote:
Originally Posted by v8volvo View Post
If you have access to a spare injection pump (even one off a different engine, i.e. 1.6L VW diesel, older TDI, etc), the pump head screws (the ones that hold the iron pump head onto the aluminum body) are the same thread as the cold start thermostat housing screws, but longer. They can help to get the process started of putting it back together.

Or better yet, if you haven't taken your existing CS housing apart yet already, there is a method that member ngoma devised and showed me that is the easiest of all. Before starting to loosen any screws, can pick up a set of small needle-nose vise grips (locking pliers), pull the rubber accordion boot forward off of its position at the point where the cable exits the housing, and clamp your vise grips onto the cable there to prevent it from receding back into the housing as you take the screws out. This way the springs stay compressed even while you have the rear part of the housing removed, so that you can put it back together with ease. The only tricky part with this method is working around the pair of pliers that are sticking out and running into your wrench.... but that is still easier than fighting those springs on reassembly.
Can we make a sticky out of this? Also to include this (w/ photo):
Quote:
Originally Posted by ian2000t
Did as in pic 2 in this thread - put one of the wire screw connector blocks on the the cable before taking it apart. Dane as your pliers idea but easier to work around.
Seems this comes up fairly often.
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  #19  
Old 05-10-2012, 02:12 AM
ian2000t ian2000t is offline
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Quote/use the pic by all means - might want to correct my type though - "Dane = Same" lol!

Well, it's fitted and working now!
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1990 Volvo 765 D24Tic (factory UK spec Tic). Monark 273 nozzles 163bar, Ajusa MLS gasket, 16psi, Water Injection, 17" Titans with 25mm H&R spacers, running 85% WVO/SVO.
http://i103.photobucket.com/albums/m...AG0269-sig.jpg
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  #20  
Old 05-12-2012, 06:44 AM
v8volvo v8volvo is offline
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Quote:
Originally Posted by ngoma View Post
Can we make a sticky out of this? Also to include this (w/ photo):

Seems this comes up fairly often.
Good idea, I will see if I can figure out how to do that. There is quite a lot of good info scattered throughout the forum at this point and I have been thinking it might be a good project sometime to compile a "How-To" thread that would consolidate the frequently-asked-about stuff in a place that is easy to find.

Quote:
Originally Posted by piper109
Are you in Europe for vacation reasons or VW reasons? Either way, enjoy the food and liquid refreshment. Just pretend that 1 Euro = 1 dollar, unless you are in UK of course. A well lubed pub lunch will dull the pain :-)
Steve, I have been enjoying a week in the Basque Country of Spain before traveling to the area formerly known as Yugoslavia after the weekend. You are right that travel and living is not cheap here... however the local wine is good and not expensive, which makes it a little easier to take.

Of course there is a preponderance of very nice diesel cars here as well, almost all of which are unobtainable in the States. It is not uncommon to cross a large street in front of traffic stopped at a light, and realize that every vehicle there has the sound of an idling diesel engine coming out of it. An enviable scernario, at least to my mind. Not a ton of old Volvos or other old cars in general but many nice newer diesel Volvos, D5 V70's, etc. I like the TDI Skodas as well.

Ian, glad to hear that you got it installed and set up. I suspect that your slight decrease in low-end snap will be accompanied by reduced smoke, better mileage, and less noise along with increased engine life. I suppose only time will tell in the case of the last one though. ;-)
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