D24T.com  

Go Back   D24T.com > Technical Discussion Area > Diesel Engine and Drivetrain

Reply
 
Thread Tools Display Modes
  #51  
Old 05-28-2020, 09:41 AM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default YouTube video of running engine

https://youtu.be/v29gB_mmy-k

Running on my stand with a temporary cooling system.

I still need to:
Resolve the oil cooler thermostat problem.
Pop test all injectors and put in new nozzles if necessary.
Attach alternator. I found one from a 1990 Audi 200 2.2 Turbo that will work.
Install a working waxstat for the timing advance system. I found some on Amazon UK.
Properly adjust the valves when the new pucks arrive.
Find a gasket for the turbo wastegate.
Determine how to attach the throttle cable once engine is installed.

I also still need to figure out how to plumb in the fuel supply and return and wire in a manual glow plug switch.
__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg
Reply With Quote
  #52  
Old 05-28-2020, 10:02 AM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default Link to another 2.0TD build

http://vwdiesel.net/forum/index.php/topic,25252.0.html
__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg
Reply With Quote
  #53  
Old 05-28-2020, 08:25 PM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default Potential oil cooler thermostat solution

In my other post here:

https://www.d24t.com/showthread.php?t=2036

I've come across a potential solution to the waxstat shortage.

If the internal part of an appropriate thermostat is removed it should replace a waxstat.

Clockwise from upper left: the valve from the oil distributor on my 2.0TD, the thermostat (or waxstat) from that valve, the internal part from a 1.6 TD thermostat, a complete 1.6TD thermostat.



I'll post any solutions in my search for a correct thermostat/waxstat on that thread.
__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg

Last edited by Nevadan; 05-28-2020 at 08:27 PM.
Reply With Quote
  #54  
Old 05-30-2020, 12:06 PM
v8volvo v8volvo is offline
Supporting Member
 
Join Date: Jun 2009
Location: Montana, USA
Vehicle: '86 745, '83 764
Posts: 1,618
Default

Looks great so far. You are really making swift progress on this project! Puts most of the rest of us here to shame!

I have a couple of spares of the cold start timing advance device wax thermostat in case UK Amazon doesn't pan out. Have the Bosch number I could read from them too. I ordered them through a fuel injection rebuilder shop using that Bosch number a while ago and they were able to get them no problem, I think around $40 each. Not bad.

Following your other R&D on the oil cooler thermostat reengineering project, looks like you have a clever solution in the works for that, thanks for sharing it.

For the fuel system, one trick I have used on a couple gas to diesel conversions that worked well was to just put a return bypass in, that tees from the high pressure gasoline supply line right into another tee in the return, before the diesel fuel filter head. Since the supply plumbing is usually a little larger diameter than the return, this results in just a little bit of positive pressure (maybe 3psi or less) -- just what the VE pump wants -- with plenty of volume delivery, and then the internal transfer pump in the VE pump does the rest to pull it from there. Much simpler than trying to strip the pump out of the pickup in the tank, or installing an expensive pressure regulator like what is used for a carburetor. The gasoline tank pump pumps diesel just fine. Having a little positive pressure makes changing fuel filters much easier too, a nice feature. If there is an inline gasoline fuel filter it can be bypassed and removed, assuming you plan to retain the stock diesel engine mounted fuel filter.

To get the gasoline fuel pump to know to run when the "dumb" one-wire mechanical diesel engine is running (usually they're triggered by the gasoline ECU or something else in the gas engine control system that presumably you will remove), I have had pretty good luck building a simple control circuit using two relays: one NO (normally open) relay that is triggered on the positive side to activate the tank pump under conditions of starter engaged and/or glow plugs energized, and a second NC (normally closed) relay controlled on the ground side by the alternator D+ circuit, which grounds with the engine stopped (opening the relay's circuit) but floats when the alternator is turning and charging (closing the circuit and activating the pump). That way the fuel pump operates to prime the system whenever you have the glow plugs on or the starter cranking, then it continue running when the engine starts and the alternator is spinning. But, if the engine stalls for whatever reason, or is not started shortly after the key is first turned on, the electric tank pump doesn't needlessly run forever with the engine stopped. (Or heaven forbid, in the case of an accident, you also want the pump to be designed to quit running when the engine stops, so it doesn't keep pumping fuel all over the place and increase the risk of fire.)

Anyway maybe that idea helps with your situation. Done something like this a handful of times and it has been successful for me at least. Another way to do it could be with a time-delay NO relay in place of the first relay I described above, that runs the pump for 30 seconds or a minute or something like that every time the key is turned on, and then the second relay (NC, controlled by alternator, or optionally you can also use the oil pressure switch for that one) takes over when the engine starts. But those timer relays have always been a little harder to find and more expensive than just a standard 5-pole Bosch type relay. I guess an old "slow-glow" type glow plug relay like from a very early Rabbit diesel could always be used as a timer for this, if you had one on hand, with the temp sensor circuit left disconnected to provide maximum engagement time.

Some gas Volvos have it even easier for diesel swaps, with a low pressure lift pump in the tank in addition to the high pressure inline pump under the rear seat. On those you can just leave the low pressure pump in place and running, and remove the high pressure pump/filter assembly, and it results in a nice low pressure high volume fuel supply perfect for the VE pump. If memory serves, though, CIS gas VW/Audi cars of the era of your QSW would have only one high pressure pump in the tank so this solution wouldn't be available to you.
__________________
86 745 D24T/ZF 345k lifted 2.5"
83 764 D24T/M46 155k
Reply With Quote
  #55  
Old 05-30-2020, 12:18 PM
v8volvo v8volvo is offline
Supporting Member
 
Join Date: Jun 2009
Location: Montana, USA
Vehicle: '86 745, '83 764
Posts: 1,618
Default

Quote:
Originally Posted by Nevadan View Post
Head gasket holes identified. Thanks for your knowledge v8volvo.
It's very visible what the head gasket is doing to the water flow. Your issue of overheating in subzero temps is another item.
Yes, this shows what I was talking about.

On a D24T gasket it's even more visibly pronounced in terms of the disparity of hole size from front to back. I guess on the 6cyl version the rear of the engine is even farther from the water pump, so an even more dramatic difference is needed to keep the flow uniform throughout the engine. With the 5cyl the fluid dynamics task is proportionally easier I suppose.

Interesting to also observe that the holes are larger on the intake/exhaust side of the engine, where heat transfer from the exhaust ports into the head must be something they wanted to accommodate with extra coolant circulation on that side. I would have thought on an IDI engine they would want plenty of coolant flow around the prechamber area too since I think those create a lot of heat transfer, but maybe the exhaust area is still much greater.
__________________
86 745 D24T/ZF 345k lifted 2.5"
83 764 D24T/M46 155k
Reply With Quote
  #56  
Old 06-01-2020, 10:54 AM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default

Quote:
Originally Posted by v8volvo View Post
Looks great so far. You are really making swift progress on this project! Puts most of the rest of us here to shame!

I have a couple of spares of the cold start timing advance device wax thermostat in case UK Amazon doesn't pan out. Have the Bosch number I could read from them too. I ordered them through a fuel injection rebuilder shop using that Bosch number a while ago and they were able to get them no problem, I think around $40 each. Not bad.

Following your other R&D on the oil cooler thermostat reengineering project, looks like you have a clever solution in the works for that, thanks for sharing it.

.
That was a long 3 day weekend to get it rebuilt. I had complete access to that nice shop and had to get it done and out of the way. I'll have weekend access until I get it complete.

I'll check with my local Bosch pump and turbo shop and see if they can still get them here.

I'll keep the oil cooler thermostat thread going as I do more research.
__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg
Reply With Quote
  #57  
Old 06-01-2020, 11:24 AM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default

Quote:
Originally Posted by v8volvo View Post

For the fuel system, one trick I have used on a couple gas to diesel conversions that worked well was to just put a return bypass in, that tees from the high pressure gasoline supply line right into another tee in the return, before the diesel fuel filter head. Since the supply plumbing is usually a little larger diameter than the return, this results in just a little bit of positive pressure (maybe 3psi or less) -- just what the VE pump wants -- with plenty of volume delivery, and then the internal transfer pump in the VE pump does the rest to pull it from there. Much simpler than trying to strip the pump out of the pickup in the tank, or installing an expensive pressure regulator like what is used for a carburetor. The gasoline tank pump pumps diesel just fine. Having a little positive pressure makes changing fuel filters much easier too, a nice feature. If there is an inline gasoline fuel filter it can be bypassed and removed, assuming you plan to retain the stock diesel engine mounted fuel filter.

To get the gasoline fuel pump to know to run when the "dumb" one-wire mechanical diesel engine is running (usually they're triggered by the gasoline ECU or something else in the gas engine control system that presumably you will remove), I have had pretty good luck building a simple control circuit using two relays: one NO (normally open) relay that is triggered on the positive side to activate the tank pump under conditions of starter engaged and/or glow plugs energized, and a second NC (normally closed) relay controlled on the ground side by the alternator D+ circuit, which grounds with the engine stopped (opening the relay's circuit) but floats when the alternator is turning and charging (closing the circuit and activating the pump). That way the fuel pump operates to prime the system whenever you have the glow plugs on or the starter cranking, then it continue running when the engine starts and the alternator is spinning. But, if the engine stalls for whatever reason, or is not started shortly after the key is first turned on, the electric tank pump doesn't needlessly run forever with the engine stopped. (Or heaven forbid, in the case of an accident, you also want the pump to be designed to quit running when the engine stops, so it doesn't keep pumping fuel all over the place and increase the risk of fire.)

Anyway maybe that idea helps with your situation. Done something like this a handful of times and it has been successful for me at least. Another way to do it could be with a time-delay NO relay in place of the first relay I described above, that runs the pump for 30 seconds or a minute or something like that every time the key is turned on, and then the second relay (NC, controlled by alternator, or optionally you can also use the oil pressure switch for that one) takes over when the engine starts. But those timer relays have always been a little harder to find and more expensive than just a standard 5-pole Bosch type relay. I guess an old "slow-glow" type glow plug relay like from a very early Rabbit diesel could always be used as a timer for this, if you had one on hand, with the temp sensor circuit left disconnected to provide maximum engagement time.

Some gas Volvos have it even easier for diesel swaps, with a low pressure lift pump in the tank in addition to the high pressure inline pump under the rear seat. On those you can just leave the low pressure pump in place and running, and remove the high pressure pump/filter assembly, and it results in a nice low pressure high volume fuel supply perfect for the VE pump. If memory serves, though, CIS gas VW/Audi cars of the era of your QSW would have only one high pressure pump in the tank so this solution wouldn't be available to you.
Excellent solution for the fuel supply! I'm not that good with wiring relays but will figure it out, I have to do similar relay work with a larger high amp cooling fan I'm putting in.

I was thinking about gutting the pump and putting some one-way flow restrictors in the supply line but I like your idea in the second paragraph much better.

I'm impressed with your knowledge and experience.

So, with the tee between the fuel supply and return line right before the filter, the pump will always be running when the car is running, subject to the conditions you've described above.

My only concern, and it's minimal, is the fuel pump is no longer available and very rare even in the junkyards.
__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg
Reply With Quote
  #58  
Old 06-02-2020, 05:47 PM
v8volvo v8volvo is offline
Supporting Member
 
Join Date: Jun 2009
Location: Montana, USA
Vehicle: '86 745, '83 764
Posts: 1,618
Default

Quote:
Originally Posted by Nevadan View Post
My only concern, and it's minimal, is the fuel pump is no longer available and very rare even in the junkyards.
No kidding. So what do the folks who want their car to stay running as a gasser do when that fuel pump dies then? Is there an aftermarket workaround?

I would have guessed it was a pretty common pump. If replacing it would be hard then it might add a benefit to your original plan of removing it, rather than retaining it. Either way ought to work though.

Watched your video, that engine sounds healthy!
__________________
86 745 D24T/ZF 345k lifted 2.5"
83 764 D24T/M46 155k
Reply With Quote
  #59  
Old 06-06-2020, 04:23 AM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default

When I get to the fuel tank I'm going to look at that pump and see if there is an alternate. It'll be several days before I get to that end of the car.

Here's a shot of the original motor with the front chopped out. I drilled all the tabs prior to using the zipwheel so I can just put it back up and bolt it in. I have no idea how anyone could get the engine out without doing this, maybe they took it out the bottom.

__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg
Reply With Quote
  #60  
Old 06-06-2020, 04:31 AM
Nevadan Nevadan is offline
Senior Member
 
Join Date: Jan 2013
Location: Reno, Nevada
Vehicle: 740/745 D24T will be mine again soon
Posts: 253
Default 33mm valve adjustment pucks! WTF??

Here's a shot of the valve adjustment pucks that just arrived. Stock pucks are 31mm, I have no idea what these fit as they were supposed to be 31mm. As I said earlier, whoever rebuilt the head ground the valves real short, still within spec but so short I need to use pucks in the 3.85 to 4.25 range of which I had only a few and none above 4.00. I'll contact the supplier next week and see what happened.

Clockwise from upper left: stock 31mm puck, new 33mm puck, stock puck on top of the new one.

Does anyone have any of these thicker ones?

__________________
J.D. in Reno
1958 Mercedes 180D (rebuilding now)
1985 VW Jetta 1.6TD
1985 Volvo 745 Wagon 2.4TD (sold but still maintain it)
1987 VW Quantum Syncro 2.2 (converting to 2.0TD)
1996 TDI Passat
1997 Chevy 3/4 ton 6.5TD
2006 V10 TDI Touareg
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 06:01 AM.


Powered by vBulletin® Version 3.8.10
Copyright ©2000 - 2024, vBulletin Solutions, Inc.