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IdahoDoug Samba Member
Joined: June 12, 2010 Posts: 10239 Location: N. Idaho
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Posted: Mon May 23, 2016 11:02 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Yeah, let's hope not, eh? This one shows attention to detail and skill so far. New VW heads, new VW water pump, sealant where it's supposed to be, nicely done HG sealant (I have them off), overheat melt out tags, quality hose clamps, new motor mounts, etc.
So, high hopes. _________________ 1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader |
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IdahoDoug Samba Member
Joined: June 12, 2010 Posts: 10239 Location: N. Idaho
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Posted: Tue May 24, 2016 8:45 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Anyone? Beuler? Heh.
Anyone know if there is a visual way to see if the bolts on this engine are new and correct? Or the old stretch type? _________________ 1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader |
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Merian Samba Member
Joined: January 04, 2014 Posts: 5212 Location: Orygun
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Posted: Tue May 24, 2016 9:13 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Doug, are there any marks on the head? _________________ .... |
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IdahoDoug Samba Member
Joined: June 12, 2010 Posts: 10239 Location: N. Idaho
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Posted: Tue May 24, 2016 9:23 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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What type of marks are you thinking of? They are VW heads, but no unusual machinist marks or other hints. _________________ 1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader |
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Merian Samba Member
Joined: January 04, 2014 Posts: 5212 Location: Orygun
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Posted: Tue May 24, 2016 9:31 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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I meant the head of the bolt - the top of the wrenching fixture.
Possibly, marks could differ from one production run to another. It is a long shot, and involves a lot of effort to match yours with others, but on some old high value sports cars, the concours geeks all search out the correct markings for their bolts. They even have databases of what mark was used when & where.
Long shot to find pics of bolts for Vanagons... _________________ .... |
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IdahoDoug Samba Member
Joined: June 12, 2010 Posts: 10239 Location: N. Idaho
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Posted: Tue May 24, 2016 9:56 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Oh, gotcha. Yeah, that's true. Both about the marks, and also the long odds of finding what marks might differentiate the stretch type bolts from the good ones as used in the 1.9s. Hmmm.. _________________ 1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader |
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Merian Samba Member
Joined: January 04, 2014 Posts: 5212 Location: Orygun
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Posted: Tue May 24, 2016 10:13 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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I think it is time for new bolts. You'll sleep better at night too. _________________ .... |
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IdahoDoug Samba Member
Joined: June 12, 2010 Posts: 10239 Location: N. Idaho
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Posted: Tue May 24, 2016 10:21 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Bolts are NLA, but I have new rods with non stretch bolts sold as a total unit. I think I will put them in the rebuilt block and call it good.
I found a thread that mysteriously did not come up on my search for stretch bolts but it shows I have to pull the bolts to measure the threads. Once I'm there, I might just as well use the new rods.
Thanks all. _________________ 1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader |
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Vanagon Nut Samba Member
Joined: February 08, 2008 Posts: 10347 Location: Sunshine Coast B.C.
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Posted: Tue May 24, 2016 11:34 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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IdahoDoug wrote: |
What say ye?
PS - ... Previous to this, my high water mark was successfully replacing the 3/4 slider in my Syncro trans. Which terrified me! |
Hell. You successfully went in and repaired your transaxle?
I say dive in. Make a day of it. There's lots of build or repair threads here.
I should follow my own advice and take apart my spare 2.1
Neil. _________________ 1981 Westy DIY 15º ABA
1988 West DIY 50º ABA
VE7TBN |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50259
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Posted: Wed May 25, 2016 12:47 am Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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IdahoDoug wrote: |
Bolts are NLA, but I have new rods with non stretch bolts sold as a total unit. I think I will put them in the rebuilt block and call it good.
I found a thread that mysteriously did not come up on my search for stretch bolts but it shows I have to pull the bolts to measure the threads. Once I'm there, I might just as well use the new rods.
Thanks all. |
Buying rebuilt rods is easy and doesn't add to the cost of doing the rebuild as they are about the same cost as having your rods resized. |
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IdahoDoug Samba Member
Joined: June 12, 2010 Posts: 10239 Location: N. Idaho
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Posted: Wed May 25, 2016 7:40 am Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Yeah, I bought mine from Van Cafe a few months ago when I realized I couldn't get just the bolts anymore.
Standing at the edge of the diving board.... _________________ 1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader |
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MarkWard Samba Member
Joined: February 09, 2005 Posts: 17011 Location: Retired South Florida
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Posted: Wed May 25, 2016 8:54 am Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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With the crank that had the failed rod bearing, a machine shop should be able to tell you if it is salvageable. When, possible, I have the machine shop mount the crank up in their jig and polish the journals. This keeps the stock dimensions, but gives you a better journal finish. When polishing is not enough, then they can cut the journal down .010" increments as long as you can purchase oversized bearings.
As far as the failed rod, it would need to be resized. Even when just changing fastener types, the rods should have the big ends checked for roundness prior to using them. A different type of fastener, can have an affect on the roundness. That is why a set of reconditioned rods with new fasteners, is actually a pretty good deal.
TTY bolts. My only experience with the 2.1 failure rate is based on all the mentions of it here. Since the 1.9's did not have this catastrophic failure, I can see where some might be suspect of the TTY bolts in the 2.1. Someone like Doug would catch a rod bearing failure in time to prevent the rod from coming through the case. Others with less of a feel for machinery, would drive it till the rod departed.
Rod bearings fail for a few reasons. Certainly lack of lubrication is one reason. Detonation is often more of a reason for rod bearing failure. Too lean a cylinder, consuming oil in the combustion area, too much timing for the fuel and you have cylinder detonation. The detonation/pinging will cause the rod bearing to deform squeegeeing the oil from the rod journal. Bearing starts to fail, connecting rod distorts, fasteners loose their grip and voila, you have a hole in the case. Good job Doug, catching it before it vented the case. _________________ ☮️ |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Posted: Wed May 25, 2016 1:02 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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MarkWard wrote: |
Rod bearings fail for a few reasons. Certainly lack of lubrication is one reason. Detonation is often more of a reason for rod bearing failure. Too lean a cylinder, consuming oil in the combustion area, too much timing for the fuel and you have cylinder detonation. The detonation/pinging will cause the rod bearing to deform squeegeeing the oil from the rod journal. Bearing starts to fail, connecting rod distorts, fasteners loose their grip and voila, you have a hole in the case. Good job Doug, catching it before it vented the case. |
Hmmmm........ I'm far from an expert but it makes zero sense that detonation damages the rod bearings "squeegeeing out the oil from the rod journal".
The rod bearing oil film is designed to take what? 100-200 lbs of compression and the resulting volatile explosion in the cylinder suddenly reversing the direction of travel and thrust.
A little out of time pinging ain't gonna do diddly squat to the bearing.
Now, the head and piston? Oh yeah, big damage.
Overheating from being out of time? Sure with oil damage but the actual "ping"? No way Jose.
Dave _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50259
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Posted: Wed May 25, 2016 2:38 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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djkeev wrote: |
MarkWard wrote: |
Rod bearings fail for a few reasons. Certainly lack of lubrication is one reason. Detonation is often more of a reason for rod bearing failure. Too lean a cylinder, consuming oil in the combustion area, too much timing for the fuel and you have cylinder detonation. The detonation/pinging will cause the rod bearing to deform squeegeeing the oil from the rod journal. Bearing starts to fail, connecting rod distorts, fasteners loose their grip and voila, you have a hole in the case. Good job Doug, catching it before it vented the case. |
Hmmmm........ I'm far from an expert but it makes zero sense that detonation damages the rod bearings "squeegeeing out the oil from the rod journal".
The rod bearing oil film is designed to take what? 100-200 lbs of compression and the resulting volatile explosion in the cylinder suddenly reversing the direction of travel and thrust.
A little out of time pinging ain't gonna do diddly squat to the bearing.
Now, the head and piston? Oh yeah, big damage.
Overheating from being out of time? Sure with oil damage but the actual "ping"? No way Jose.
Dave |
Detonation can both damage rod bearings and bend the rods. Detonation does not cause the oil to squish out as that takes a considerable amount of time to happen, but instead it over loads the material in the bearings causing pieces of the lining to flake off. |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Howesight Samba Member
Joined: July 02, 2008 Posts: 3262 Location: Vancouver, B.C.
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Posted: Wed May 25, 2016 3:42 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Rod bolt quality is very important. Even the best bolts only have a limited service cycle. I used to use SPS (Special Purpose Steel) rod bolts in my drag racing beetle engines. They featured tiny spherical indentations which enabled you to place spec ball bearings and use your micrometer to measure the bolt stretch - - measure first snug and then measure again after torqueing. If the stretch specification was not achieved, you would start over. These were multiple-use fasteners. I suspect that the torqueing of the 2.1 stretch bolts at the factory was not always perfect, hence the well-known disasters on one hand, and the 230,000 mile 2.1's like my old WBX on the other hand, still chugging away right up to forced (SVX) retirement.
The point is that there are so many variables in the initial torqueing of stretch bolts that the 90 degrees (plus another 90 in some cases) of "stretch" torqueing often produced different stretch in each bolt. I may be old-fashioned, but I like the idea of measuring the rod bolt stretch for highly-loaded engines. For the stock 2.1 WBX, however, it is very hard to beat the rebuilt rod offerings from Rocky Jennings and VanCafe. _________________ '86 Syncro Westy SVX |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50259
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Posted: Wed May 25, 2016 5:12 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Howesight wrote: |
I suspect that the torqueing of the 2.1 stretch bolts at the factory was not always perfect, hence the well-known disasters on one hand, and the 230,000 mile 2.1's like my old WBX on the other hand, still chugging away right up to forced (SVX) retirement. |
The stretching that leads to loss of torque and eventual failure seems to happen on only one or just two rods. The other bolts don't seem to loose their torque. Twenty-five'ish years ago when I rebuilt the blown engine in my Syncro I was pretty ignorant of the stretch bolt issue and I reused the bolts on the three rods that hadn't experienced failure. Both those three bolts and the used 1.9 rod and bolts I used as a replacement for the mangled rod all lasted until the head compression gasket failed at just shy of 300K miles, pretty much twice the mileage the one rod bolt had failed at. |
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MarkWard Samba Member
Joined: February 09, 2005 Posts: 17011 Location: Retired South Florida
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Posted: Wed May 25, 2016 6:42 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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Take a used bearing shell and measure edge to edge across the open end. Now set the shell on your bench and start rapping on the center of the shell with a hammer. This causes the ends of the shell to move towards each other. As that dimension shrinks, you can see how it would squeege the oil film away. We are talking .0015 clearance on each side.
When oil gets passed by the rings or guides it actually has the effect of increasing the btu of the fuel charge. Making the cylinder more prone to detonate. If I had to venture a guess, these high mileage 2.1 engines are having other problems that lead to a fastener failure. _________________ ☮️ |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50259
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Posted: Wed May 25, 2016 8:23 pm Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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MarkWard wrote: |
Take a used bearing shell and measure edge to edge across the open end. Now set the shell on your bench and start rapping on the center of the shell with a hammer. This causes the ends of the shell to move towards each other. As that dimension shrinks, you can see how it would squeege the oil film away. We are talking .0015 clearance on each side. |
To force the oil very far takes time, whereas the force from detonation is going to begin, peak, and dissipate in a very short time period.
Quote: |
When oil gets passed by the rings or guides it actually has the effect of increasing the btu of the fuel charge. Making the cylinder more prone to detonate. If I had to venture a guess, these high mileage 2.1 engines are having other problems that lead to a fastener failure. |
First off the btu of the fuel charge doesn't have that much to do with knock, whereas the instability of the charge does. A stoichiometric mixture is less stable than a richer mixture. Oil droplets droplets don't burn readily but once they get nice and hot can tend to seed an explosion.
If you are getting detonation damage because of oil getting into the intake system then the damage should be showing up on all the cylinders/rod bearings, whereas the rod bolt failure is typically limited to just one or less often two cylinders. The problem also has a history of being fixed by using the 1.9 rod bolts and this would have zero to do with detonation.
A pile of 2.1L engines that have been rebuilt using 1.9L rod bolts are now reaching higher mileages, if you theory is correct they should have been having rod bolt failures for years at this point in time, but they have not. |
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MayorMcCheese Samba Member
Joined: October 07, 2009 Posts: 652 Location: Lancaster PA
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Posted: Thu May 26, 2016 9:02 am Post subject: Re: Solving mystery of WBX stretch bolts - need experts ASAP. |
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New rod bolts must exist somewhere or van cafe would not be overhauling rod cores.
edit: $25 for a full set http://www2.cip1.com/ProductDetails.asp?ProductCode=C24-056-105-425-C8
Last edited by MayorMcCheese on Thu May 26, 2016 9:07 am; edited 1 time in total |
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