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Engine Specific Info and Questions => IDI Engine => Topic started by: speedy on April 04, 2010, 07:35:57 pm
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My engine and transaxle are on the floor of the garage, waiting for me to change the head gasket.
The engine is a mechanical 1.6TD out of an '85 Quantum, unknown history. It now lives in a 1973 Transporter. Has K24 turbo, 2.25" mandrel-bent exhaust, Saab intercooler. The goal is a modest 100hp and top-tier reliability.
I've spent probably 4-5 hours on this site reading up on head gaskets, studs and tools, learned a lot but I'm still not 100% sure I am making the right choices for this job. So, I'm going to post here first in the hopes that if I'm about to make a huge mistake, one of you knowledgeable types (Andrew, Vincent, et. al) will save me from myself. Here's what I have planned:
ARP studs (251-4701) from Summit Racing. About $145 with shipping (ouch). Main reason I'm going with these is because I can't re-torque the head bolts without dropping the engine and I don't want to do that two more times after I put it back in. It is my understanding that I DO NOT have to re-torque the ARP studs after the initial install. One factory sequence to 80lb-ft with ARP lube, 120lb-ft with 30-wt oil and I'm done. Right?
Head gasket - I will measure the piston protrusion once I have the head off and buy the appropriate gasket. Going with the stock-style gasket, probably the Elring from Autohausaz:
http://www.autohausaz.com/search/product.aspx?sid=evn5mbz3iyqzl0jbdpotit45&makeid=800026@VW&modelid=1284780@QUANTUM%20GL%20CUSTOM%20TDI&year=1985&cid=109@Engine%20Overhaul/Rebuild%20Kit&gid=5412@Cylinder%20Head%20Gasket (http://www.autohausaz.com/search/product.aspx?sid=evn5mbz3iyqzl0jbdpotit45&makeid=800026@VW&modelid=1284780@QUANTUM%20GL%20CUSTOM%20TDI&year=1985&cid=109@Engine%20Overhaul/Rebuild%20Kit&gid=5412@Cylinder%20Head%20Gasket)
It is my understanding that there is no readily-available head gasket upgrade for the mechanical 1.6 engine like there is for the hydraulic engine. I don't think my power goals justify an upgrade but again I would like to hear from those with differing opinions.
Measured my IP timing before disassembly. I have the correct dial indicator but do not have the stock flywheel/bellhousing so I have no TDC mark to look at. I used a flat file in the notch at the rear of the cam to determine TDC. There was some slop so I turned it one way till it wouldn't go any more, then turned it the other way, then split the difference. Wouldn't you know it, the dial indicator said .0395" in the middle which I think is just about perfect. I am going to use a dremel with a cutoff wheel to make a TDC mark on the crank pulley so that it will be possible to find TDC with the engine in the van in the future. I know it's not as accurate as the flywheel mark but I think it will be good enough. I realize that if my cam timing is off, my TDC mark will be off also. I'm just going to hope that the cam timing is accurate. The timing belt is new and the engine ran great when I pulled it (except for the pressurized coolant system!).
I will stay away from Autozone and Pep Boys triple-square tools since the results seem to be mixed on those. I am going to stop by Napa tomorrow and pick up a 10mm Lisle triple-square tool so I can get the old head bolts out. Then remove the head, clean, check for straightness, etc.
Please let me know if I am making any errors here - Thanks!
-David
p.s. I re-used the factory torque-to-yield head bolts in my 87 Mustang more than once and never had a problem. I guess I won't chance it on this engine though.
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I got my studs from headbolts.com they were much cheaper than summit, and they ship USPS so shipping is better too.
as for the TDC mark, since you will be pulling the head make that mark on the pulley after the head is off and you can guarantee exact TDC with a dial indicator.
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I checked headbolts.com but they were a few dollars more than Summit.
How can I verify exact TDC with the head off? If I'm not mistaken there will be many degrees of rotation where the piston does not move at the top of it's travel. I'm also not sure how to set up the dial indicator to measure piston travel.
Thanks,
-David
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technically there will me no point where the piston stops moving up and down, just a point where it is hard to see with your eye.
use your dial indicator in a stand to hold it to the block deck, then you will be able to see the exact point where the piston stops going up and starts going back down.
(http://www.lathemaster.com/images/dial_indicator_with_base.jpg)
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If I'm not mistaken there will be many degrees of rotation where the piston does not move at the top of it's travel.
Yer absolutely correct... which means we have to be a bit more clever when using a dial indicator to find TDC.
The trick is: don't find TDC, find a spot before and after TDC. ;)
With your dial indicator set on a magnetic clamp, rotate the engine toward TDC and stop when you get a few mm *before* TDC. Make a mark on the flywheel. Rotate the engine thru TDC and stop at the same reading you had before, making another mark. TDC is now exactly between those two marks.
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Bolt a bar or stopper across #1 piston.
rotate till piston hits stop.
mark.
rotate all the way back around till piston hist stop.
mark.
halfway between marks is true TDC, make a different mark.
You might even want to drill a hole in the bottom of the tranny so you can check it from below.
edit: Vincent is faster than me :-\
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edit: Vincent is faster than me :-\
Perhaps, but your idea is cheaper... no need for a dial indicator or clamp. :)
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I thought the ARP studs needed periodic retorquing?
I'm pretty sure the head bolts use a 12mm triple square.
The cam pulley does not have a key in it. It is infinitely adjustable so using it as a TDC reference is pointless.
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I thought the ARP studs needed periodic retorquing?
Great - just when I thought it was settled... :-\ So what led you to believe that they needed retorquing?
The cam pulley does not have a key in it. It is infinitely adjustable so using it as a TDC reference is pointless.
I don't think anyone mentioned using the cam pulley as a TDC reference.
Thanks,
-David
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Bolt a bar or stopper across #1 piston.
rotate till piston hits stop.
mark.
rotate all the way back around till piston hist stop.
mark.
halfway between marks is true TDC, make a different mark.
I'm going to try this method first - should be dead simple, just a piece of angle with two holes in it. Thanks for posting,
-David
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I don't think anyone mentioned using the cam pulley as a TDC reference.
I have the correct dial indicator but do not have the stock flywheel/bellhousing so I have no TDC mark to look at. I used a flat file in the notch at the rear of the cam to determine TDC.
Maybe I'm not visualizing this correctly.
Great - just when I thought it was settled... :-\ So what led you to believe that they needed retorquing?
Just something I thought I read. I've never used them so I could be way out in left field. If no one else says anything you can probably safely assume that...
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I would think that the head studs would only need retorque if they lost it on initial start up. When they get up to temp the material could be destressed and loosen a tad. There rod bolts are to be torqued and loosened 3 times for this reason and to make sure the cap is fully seated too. I torqued my head on with an old HG and left it sit for a month, loosened it, tightened them again...but I have time to wait to get it in there.
For most purposes I would say just check them after the first heat cycle and forget it, but I am not the expert on these.
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For most purposes I would say just check them after the first heat cycle and forget it, but I am not the expert on these.
X2 If I'm not being lazy I've rechecked them after a 1000 or 6 miles.. Typically if they've been retorqued after the first heat cycle they don't move a bit..
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Arp studs do not required a re-torque. I install them daily-their instructions never have said anything. Just use the moly lube that comes with them and torque to spec. The last 2 sets (over the last few months) of "Ford Cosworth" studs I got called for 110 ft lbs -although i know earlier sets said 80 ft lbs. My sets have a newer blend of moly paste (a blue package rather than white)-and they updated the testile strength on the studs-200,000 from 180,000.
You CAN retorque if it makes you feel better-just only do it one at a time.
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I would retq a fiber gasket... but thats just me. 8)
some do.. some dont....if it's a high boost engine or plans to be I would retq on a fiber gasket for sure!
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Well since retorquing is such a big job for me compared to someone with, say a Jetta, I will probably not do it unless (God forbid) I have the engine out for some other purpose. I may even give ARP a call just to confirm that the lack of retorque instructions was intentional. Thanks for all of the replies on this.
-David
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I called ARP today, talked to "Al". He said that re-torquing is dependent upon the head gasket, not the bolts or studs. Since I am using a factory head gasket, he said I needed to follow the factory torque procedures which includes re-torquing. Not the answer I was looking for, but there it is. I'm thinking about starting up the engine on the garage floor for the first heat cycle and re-torque, then either taking a chance and skipping the second one, or biting the bullet and doing the 6-hour engine R&R for the second re-torque. Of course, none of that may be necessary now, details in the next post. :(
-David
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I finally got comfortable enough with cam/injection pump timing to remove the cam pulley and take the head off the block.
The good news is that I found some evidence of a water breach. The head bolt between cylinder 3 and 4 on the back of the engine (intake and exhaust side) came out all rusty and there is some corrosion around the water port next to it leading to cylinder #3. It's not a slam dunk, but since the water obviously made it through the gasket to the head bolt, it is pretty likely that it also made it through the gasket to the combustion chamber, or rather the reverse happened (combustion chamber gasses made it into the water passage). Here is a link to a shot of that area (warning: large image):
http://motorheads.net/vw/gtd_forum/water_leak.jpg (http://motorheads.net/vw/gtd_forum/water_leak.jpg)
The bad news is twofold. First, there are cracks between the valves on all four cylinders. I was prepared to see that but I am a little uncomfortable with the size of the cracks and how much they have opened up. Here is a low-res picture of one of the worse cracks:
(http://motorheads.net/vw/gtd_forum/crack_from_distance_cyl2_small.jpg)
Links to high-res pictures of all four cylinders:
http://motorheads.net/vw/gtd_forum/crack_cyl_1_closeup.jpg (http://motorheads.net/vw/gtd_forum/crack_cyl_1_closeup.jpg)
http://motorheads.net/vw/gtd_forum/crack_cyl_2_closeup.jpg (http://motorheads.net/vw/gtd_forum/crack_cyl_2_closeup.jpg)
http://motorheads.net/vw/gtd_forum/crack_cyl_3_closeup.jpg (http://motorheads.net/vw/gtd_forum/crack_cyl_3_closeup.jpg)
http://motorheads.net/vw/gtd_forum/crack_cyl_4_closeup.jpg (http://motorheads.net/vw/gtd_forum/crack_cyl_4_closeup.jpg)
Then more bad news - when I wiped off the tops of the pistons, I found some pitting in cylinder #4. Note that it is not visible in the water leak picture above due to being covered with a very light layer of carbon:
(http://motorheads.net/vw/gtd_forum/pitting_small.jpg)
Link to high-res image of pitting:
http://motorheads.net/vw/gtd_forum/pitting.jpg (http://motorheads.net/vw/gtd_forum/pitting.jpg)
Am I screwed? This engine ran pretty well when I took it apart except for the pressure in the coolant system. Can I just bolt it back together and expect it to survive? Or should I just start over with a new engine?
Thanks,
-David
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Based on that picture those are very reasonable cracks between valves... very reasonable. You'll want to carefully clean the head and look for cracks in other places, but if that's the worst you've got yer fine.
In terms of the piston erosion I'd say you need to pull the piston and if the erosion has impacted the area around the top ring at all. If the picture is pretty much shows it all again you're probably also good to go... unless you're a serious perfectionist. ;)
And of course that errosion tells you you really really really need new nozzles. :o
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Thanks Vincent, I feel better now. I read your writeup on rebuilding IDI injectors, very nice. I think I will disassemble and inspect the #4 injector tomorrow and see if I can find the cause of the problem.
-David
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The double crack on #2 is a bit worrying to me.
Visually you can look around the needle on the injector. If it's deeply eroded you can guess that's probably no longer spraying very well. You can do that without taking them apart. Like Libbybapa said, without a pop tester you can't see much else.
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I just stumbled across this post. Great project BTW.
I have an idea that you may or may not have already considered adding a T3 Vanagon style upper engine lid. That would make a world of difference in adding lots of engine accessibility for re-torquing your head studs. A bit of work, yes but so is pulling your engine 2 or 3 times to re-torque.
How did you go about the radiator? How about IC placement and plumbing? Did you go with a KEP adapter or OEM brazilian bellhousing? At some point I'd like to do this swap to my '74 Westy but for now the 2.0L is healthy enough that replacement would be "creating" work I don't have time for. Sorry to go off topic somewhat. ;)
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I called ARP today, talked to "Al". He said that re-torquing is dependent upon the head gasket, not the bolts or studs. Since I am using a factory head gasket, he said I needed to follow the factory torque procedures which includes re-torquing. Not the answer I was looking for, but there it is. I'm thinking about starting up the engine on the garage floor for the first heat cycle and re-torque, then either taking a chance and skipping the second one, or biting the bullet and doing the 6-hour engine R&R for the second re-torque. Of course, none of that may be necessary now, details in the next post. :(
-David
I did ARP studs and fiber gaskets in both my 1.6/1.9 franken motor and the 1.5TD. Re-torq is necessary. Quite a few studs took more twist in both engines. No leaks! ;D
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I have an idea that you may or may not have already considered adding a T3 Vanagon style upper engine lid. That would make a world of difference in adding lots of engine accessibility for re-torquing your head studs. A bit of work, yes but so is pulling your engine 2 or 3 times to re-torque.
I have considered that, and someday may do it when my welding skills have improved to the point where I won't make a total mess of it. So far though, I haven't found the smaller hatch to be much of a problem. This is the first time I have wished for more room.
How did you go about the radiator? How about IC placement and plumbing? Did you go with a KEP adapter or OEM brazilian bellhousing? At some point I'd like to do this swap to my '74 Westy but for now the 2.0L is healthy enough that replacement would be "creating" work I don't have time for. Sorry to go off topic somewhat. ;)
I have dual radiators under the floor. Intercooler is a Saab unit going in the left side battery box, using 2" exhaust tubing and silicone couplers (not finished yet). KEP adapter. All of the details are on my web page:
http://motorheads.net/vw/turbobus (http://motorheads.net/vw/turbobus)
I understand your reluctance to take out a perfectly good engine - I would not have done that to mine either, but fortunately (?) my engine was on its last legs.
-David
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Thanks for all of the replies on the head cracks and piston erosion. I have decided to put the engine back together and run it - if/when it dies, I will consider it an "opportunity to upgrade" and swap it for a 1.9L.
I called a couple of diesel shops here in the Dallas area today, but none of them would work on less than an 18-wheel truck engine. Any chance I can get away with just buying a rebuilt Bosch injector to replace the one that was in #4? Or can someone recommend a place in the Dallas area that can do the pop test for a reasonable price or sell me a good used injector?
Finally, I checked my valve lash and #1 intake is .005". I don't have the tool or any shims to adjust it with. Okay to leave it at .005 or should I bite the bullet and buy the tool/shims? The rest of the valves are all within spec (8-12 intake, 16-20 exhaust).
Thanks,
-David
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I have a shim kit and if you cover shipping and send me your old shim I`ll send you the proper size.
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Have to agree on the threatening appearance of that 'double-crack' in #2 combustion face.
I'd at least drop the $30. or so it costs to have a machine shop pressure-test the cylinder head. If it does have a leak, it's just wasted time & money to put it back in 'as is', especially with all the good efforts you've put into the project already.
Some have said there are actually talented welders/machine shops who can successfully weld up these almost-universal cracks... IDK. If true, I'd like to know where they're hiding. ???
Good luck with it.
J.R.
SoCal
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I found a local shop to pop test the injectors. Able Fuel Injection Service (http://diesel-fuel-injection.com/ (http://diesel-fuel-injection.com/)). They told me that the #4 injector was fine, so the damage to the piston must have come from something else (being that the history of the engine is unknown, it could have been just about anything). They did say that the #1 and #3 injectors were leaking and that all were very worn and recommended I let them rebuild all four injectors at $55 each. Normally this kind of response raises the hair on the back of my neck, but I got good vibes from this place so I told them to go ahead. They said they use only Bosch parts. When I got home and looked into the holes where the injectors had been, I saw a lot of soot and carbon in the #1 and #3 holes and none in #2 and #4, which is in line with what they told me. I get the injectors back tomorrow.
I also removed the camshaft to adjust some of the shims. I do not have a Bentley manual (I am too cheap to pay $100 for a manual that covers all gas/diesel Quantums when I don't even have a Quantum any more, only have the diesel engine in a different vehicle) so I hope someone would be kind enough to tell me how to retorque the cam once I am done. Couldn't seem to find it with the search.
Thanks,
-David
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VW service manual says to set cam to #1 TDC, and install caps #2 and #4 first. Torque down alternately/diagonally. Final value is 20NM. It doesn't say, but I'd do it in 2 stages.
#1 cap, is next to pulley. Then do #1, 3, and 5 [I assume zig zag, although it doesn't specify]
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Just my two bits but...
I had similar cracks with my MF and even had slightly worse damage on my #1 piston. I worried the issue for days, then decided to roll with it. 65'000 kms later and no problems at all. Unless you are gong for mint, there is no harm in going with what you see. As others have said, there can be much, much worse. These engines are damned near bullet proof. Being as it is going into a doghouse, I would have the pump reconditioned as well as the injectors. And change every hose and belt you can see! That should buy you a couple years.
Should be a solid bus when you are done.
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VW service manual says to set cam to #1 TDC, and install caps #2 and #4 first. Torque down alternately/diagonally. Final value is 20NM. It doesn't say, but I'd do it in 2 stages.
#1 cap, is next to pulley. Then do #1, 3, and 5 [I assume zig zag, although it doesn't specify]
Thanks Mark, I will follow that procedure... carefully!
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I had similar cracks with my MF and even had slightly worse damage on my #1 piston. I worried the issue for days, then decided to roll with it. 65'000 kms later and no problems at all. Unless you are gong for mint, there is no harm in going with what you see. As others have said, there can be much, much worse. These engines are damned near bullet proof. Being as it is going into a doghouse, I would have the pump reconditioned as well as the injectors. And change every hose and belt you can see! That should buy you a couple years.
Turftech,
I have not reconditioned the pump, but I do have a rebuilt one sitting on the shelf waiting for the day I need it so no worries there. I picked up the injectors today, they look great except that the shop engraved six-digit numbers on them... what's with that? Their own serial number? I thought they were MY injectors. >:( Belts are all new, hoses will be as soon as I get a configuration I'm happy with (I think I'm getting close). Checked my log book and the last time I put fuel in the bus was August 2009! It's time to get this project rolling again so I am going to try to pick up the pace. Thanks for the reply,
-David