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  #21  
Old 05-21-2020, 11:16 PM
Nevadan Nevadan is offline
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Quote:
Originally Posted by Goteborg Vapenfabrik View Post
Ive discovered saving sheet steel parts that are badly rusted to be a simple process with the oxy-acetylene powered DHC 2000 welding kit. It could be a valuable tool for your 2.0TD oil pan repair project. It can be used with standard regulators. Of course as always safety first.
I hope the pan from the 2.2 gas engine fits, but won't know til I take that engine out. I'll have to look up DHC 2000 welding kit, since I've never heard of it. I temporarily welded a small piece on the pan where it was completely rusted through. I got this engine from Canada and everything that's exposed to atmosphere is rusted. I got everything off the block today using a lot of map gas heat, well everything but one glow plug, it wouldn't come out and I twisted off the head. I'll drill and easy out the thing on another day. I had to chisel off a few of the turbo to downpipe nuts as well. All the interior parts, including gaskets appear to be in good condition.
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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
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  #22  
Old 05-21-2020, 11:24 PM
Nevadan Nevadan is offline
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Originally Posted by v8volvo View Post
I was going to ask what you were planning to do about gearing, but then I didn't because I think you're right, the gasser gearing will probably be fine as is. These old IDI motors like to rev and there are seemingly no downsides to letting them do it. In the example of the Volvos, the diesel models use exactly the same transmission and rear axle gearing from the factory as most of the equivalent gas models. In fact the diesels are actually geared shorter than some of the NA gassers. The engines are suited by design for fairly high engine speeds, small lightweight pistons, direct acting OHC valvetrain, etc, it was clearly part of the plan for them. Especially true for the original design "short stroke" family like the D24/T and your "D20T" (the 1.5/1.6 4cyl, 2.0 5cyl, 2.4 6cyl). The raised deck generation IDI and TDI motors (1.9/2.0 4cyl and 2.4/2.5 5cyl) with longer strokes are maybe a little less optimized for it.

Anyway if the gas engine is turning 3200 at 70 that seems like it would be just fine with the diesel. My '83 760 D24T with stock size tires and stock gearing turns about 3400 rpm in overdrive at 85mph, which is still too slow to keep up with highway traffic here. But it seems happy to do those revs or more all day, in fact it seems to be capable of quite a bit more, although with the 1983-only 85mph speedo I am not too tempted to explore. Really the ability to rev smoothly and provide a wide power band is one of the neat features of the old IDI turbo engines, and makes them fun to use for hard driving. The later direct injection engines are much more limited on the top end, although their low end response is better. They seem to pretty much run out of breath even before 4000 rpm.
My 1.6 doesn't really generate good power until around 3000rpm's. When I owned the D24T Volvo I recall it had good power below 3000 but didn't mind running at 3500 either. TDI's are better between 2000 and 3000. I think it will be fine which is why, 9 years later, I'm continuing with the project.

I did a compression test before dismantling all the exterior bits today and it was pretty sad, around 280 psi average, but the engine has been sitting a long time. It did hold pressure so I think it will be ok. There was one potentially major problem, the #4 injector was burned up on the tip, I think the crush washer wasn't seated properly by the PO and it wasn't emitting diesel, so that cylinder was running dry for I don't know how long. It only had 50psi dry, but when I put oil in the cylinder it went up to 220.

I'll be taking the head off tomorrow and see what's up. Stay tuned.
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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
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  #23  
Old 05-22-2020, 10:42 AM
ngoma ngoma is offline
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Here's a partial answer about your thermostat/coolant flow questions:

In the 7xx series at least, the heater valve is always open, except when running max A/C.

Might want to check that your tstat is the correct one. I would have thought that when fully opened, the block-off disc would completely close up the recirculation port-- isn't that what it's there for?

Greenbook shows the disc should move 8mm min. (fully open) at 216degF (for stock 87degC tstat).
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  #24  
Old 05-22-2020, 10:45 AM
ngoma ngoma is offline
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OK I see my misunderstanding of your question about blocking the recirc port.
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  #25  
Old 05-22-2020, 08:45 PM
Nevadan Nevadan is offline
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Quote:
Originally Posted by ngoma View Post
OK I see my misunderstanding of your question about blocking the recirc port.
Interesting question, right. I hope to get some feedback. There's no flow out of the back of the head/block. On the 1.6 in my '85 Jetta the heater core circuit is always open so there's always flow out the back of the block/head.
__________________
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
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  #26  
Old 05-22-2020, 08:57 PM
Nevadan Nevadan is offline
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Day 2 update.
Cylinder walls 1 through five in sequence. #4 is the problem, as stated earlier the injector for that cylinder was burned closed, ie. no fuel injected, so the piston was just going through the motions without any action. That's also the cylinder I snapped the glow plug head off, and still can't get it out. There's some rust on the walls but that's about it. The walls themselves look good and there's very little lip at the top where the rings finish their stroke. I'm just going to do a light hone and install new rings.









__________________
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; 05-22-2020 at 09:00 PM.
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  #27  
Old 05-22-2020, 09:04 PM
Nevadan Nevadan is offline
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Head gasket and head. I'm convinced this engine was recently overhauled, recent in miles or hours not recent in days or years. That's a clean looking gasket. It's hard to see in the photo but there's only one small crack between the valves. I still need to get the frozen glow plug out of cylinder number 4 but the head is very useable.
__________________
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
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  #28  
Old 05-22-2020, 09:07 PM
Nevadan Nevadan is offline
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Indication of prior rebuild, punch marks on the rods and caps.
__________________
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
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  #29  
Old 05-22-2020, 09:09 PM
Nevadan Nevadan is offline
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Broken oil squirter in cylinder 1, I have one, I think I got them from Anders several years ago.
__________________
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
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  #30  
Old 05-22-2020, 09:13 PM
Nevadan Nevadan is offline
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Join Date: Jan 2013
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Vinegar soak! I'll leave the vinegar in the block overnight and flush it out tomorrow, will probably do one more soak tomorrow night. The block holds 3 quarts of water/vinegar.
__________________
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
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