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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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 Posted: Mon Jan 13, 2020 6:40 pm Post subject: Rod stretch bolt ID? |
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Im currently going through a refresh on my 91 westy 2.1 DJ engine. It’s a VW Canada reman engine from the late 90’s or early 2000’s and I’m wondering if they changed out the rods or bolts to the earlier non stretch style at that time. Can’t seem to find any info on IDing them so wondering if someone on here might know or be able to shed some light on the matter by looking at these pics.
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
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vanagonjr
Samba Member
Joined: October 07, 2010
Posts: 3431
Location: Dartmouth, Mass.
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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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| Posted: Mon Jan 13, 2020 8:17 pm Post subject: Re: Rod stretch bolt ID? |
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I swear I even used the search function, not sure how I missed that!
Thanks guys.👍
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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jlrftype7
Samba Member
Joined: July 24, 2018
Posts: 3577
Location: Chicago
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| Posted: Mon Jan 13, 2020 8:29 pm Post subject: Re: Rod stretch bolt ID? |
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Just as added info if anyone reading the older posts on this doesn't understand the term TTY.. That's Torque To Yield in the Automotive world, many engine Head Cyl. Bolts and other internal hardware can be TTY these days.
Not always a bad thing. BMW solved Cyl. Head bolts snapping at the head with superseding to TTY Cyl. Head bolts on their M-20 engines years ago.
Just wait till you get to Trilobular bolts.... Luckily not a 'Thing" with our Vanagons..... 
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'68 Westy- my first VW and vehicle/Bus- long gone.- sold it to a traveling Swiss couple....
'67 Type 3 Fastback, my 2nd car- gone
'69 Semi-Auto Stick Shift Beetle-gone
2017 MINI Coopers, our current DDs
‘84 Tin Top - Hilga....Auto |
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Howesight
Samba Member
Joined: July 02, 2008
Posts: 3274
Location: Vancouver, B.C.
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| Posted: Mon Jan 13, 2020 8:44 pm Post subject: Re: Rod stretch bolt ID? |
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Hey Trevor:
A quick comment to save you some heartbreak later - - both the 2.1 and 1.9 connecting rods require "rebuilding" any time the bolts are replaced. I see your stable includes a lot of rigs that had 40 horse and even 36 horse engines in which the rod bolts don't critically index the connecting rod caps to the rods. The 1.9 and 2.1 rod bolts do index the rod and cap. Replacing the WBX connecting rod bolts affects that indexing.
The 2.1 and 1.9 rods should always be checked for twist, re-bushed and the big end re-sized and honed with the new bolts in place. Rocky Jennings and VanCafe both sell rebuilt connecting rods (balanced, too) with all this work done for you, and at a reasonable price.
These vendors we are blessed with today make VW life so easy. Back in the late 1970's when I started seriously drag racing a 2180 Beetle, we had to buy a bunch of used con rods, grind the beam flash off, balance, polish, magnaflux them (tossing the bad ones), and then shot peen the whole rod before grinding the join. Then the bolt holes were reamed for 3/8" ARP Special Purpose Steel bolts ($25 a set back then!) and the big end was honed to size. I knew very few folks (being a poor teenager myself) who could afford the prices Carrillo was asking for their rods back then and Scat was just starting to get into forging parts. I lived near a stock-car racing engine builder who did all my machining and was quite patient with my many teen newb questions.
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
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| Posted: Mon Jan 13, 2020 8:48 pm Post subject: Re: Rod stretch bolt ID? |
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| jlrftype7 wrote: |
Just as added info if anyone reading the older posts on this doesn't understand the term TTY.. That's Torque To Yield in the Automotive world, many engine Head Cyl. Bolts and other internal hardware can be TTY these days.
Not always a bad thing. BMW solved Cyl. Head bolts snapping at the head with superseding to TTY Cyl. Head bolts on their M-20 engines years ago.
Just wait till you get to Trilobular bolts.... Luckily not a 'Thing" with our Vanagons..... |
The 2.1L WBXer bolts really don't look like stretch bolts. It could be the TTY spec is too high for the bolts and if you just torqued them to a lower spec they might not give any problem.
I didn't know anything about the history of these engine throwing rods when I bought my Syncro with a thrown rod way back in the early 90's. I located a used 1.9 rod to replace the failed rod (no 2.1L engines seemed to have made it to the areas wrecking yards by then) and asked my very knowledgeable VW-Porsche machinist what to do about the rod bolts and he said just to run all of them and not worry about the differences. I ran that engine a lot of miles before it failed due to coolant getting into the combustion chamber. Never a problem with either the three 2.1L rods with used TTY bolts or the one 1.9L rod with the earlier 1.9L bolts. Don't remember what torque spec I used for the nuts. |
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vanagonjr
Samba Member
Joined: October 07, 2010
Posts: 3431
Location: Dartmouth, Mass.
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| Posted: Tue Jan 14, 2020 11:28 am Post subject: Re: Rod stretch bolt ID? |
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| Wildthings wrote: |
The 2.1L WBXer bolts really don't look like stretch bolts. It could be the TTY spec is too high for the bolts and if you just torqued them to a lower spec they might not give any problem.
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Yes, good points Wildthings. I know people call them stretch bolts, and even manuals call them that at times, but really it is (likely) a standard bolt geometry and it is just using torque to yield tightening. It is also possible that the specs for the torque to yield were not quite correct, and therefore it is possible that tightened to a lower torque they would have been fine.
I've developed torque to yield for bolts in my job ( torque + an angle, such as 90 degrees) and one thing you never have is a the absolute worse case condition. Bolt geometry on minimum, internal thread on maximum, bolt at minimum hardness, and the most important - the finish having the lowest coefficient of friction it will ever have.
It is also interesting to note that "rod bolt failure" on this engine are on #3 cylinder. That means either #3 exerts more stress than the others (unlikely) or there something else going on, like oil starvation or bearing seizing, etc. that then creates a high stress causing the bolt to fail.
If I had a customer come to me and say it's the bolt's fault and it's used in multiple other places w/o problems, then let's take a look at the application.
But it always the bolt's fault....
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John - 86 Wolfsburg Westfalia "Weekender"
Flint reversed 1.8T W/Passat 5-Speed
LiMBO (late model bus club) www.limbobus.org
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FAQ thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=525798 |
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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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| Posted: Tue Jan 14, 2020 11:35 am Post subject: Re: Rod stretch bolt ID? |
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So what is everyone using for a torque value on the replacement rods that are available from vendors? Some vendors say they are TTY and some say they use the older style bolts (and some make no mention of bolt style) yet everyone is using the same part # for the rod listings. I’m not comfortable reusing these now that I have it apart and for the cost of a new set of rods it’s not worth the risk.
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17121
Location: Retired South Florida
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| Posted: Tue Jan 14, 2020 12:51 pm Post subject: Re: Rod stretch bolt ID? |
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When we rebuild any engine, which is less and less often, the rods along with all the other rotating parts get sent to the local machine shop to be measured and checked. If necessary, the machine shop does the necessary machining including resizing and rebushing connecting rods.
I don't think my machine shop can match the price on Van Café reconditioned rods. But here's the catch. Rods are originally in weighted sets. When you have a bucket of connecting rods, you can get pretty close, but they are not an original set. I'd want to keep my original set.
When connecting rods are fitted with new fasteners, stock or ARP, it's best practice as mentioned assemble torque to spec and verify they assemble properly. A machine shop has the tools to check and if necessary resize with the new fasteners.
You can skip a lot of steps reassembling an engine and might even get lucky, but reliable engines should leave nothing to chance. Reading the Samba thread above, it mentions how to measure the thread length to determine which fastener you have. Without a ruler and using my eye, it looks like you have the TTY which I recall was 33 mm thread length.
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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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| Posted: Thu Jan 16, 2020 8:38 pm Post subject: Re: Rod stretch bolt ID? |
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| vanagonjr wrote: |
Yes, good points Wildthings. I know people call them stretch bolts, and even manuals call them that at times, but really it is (likely) a standard bolt geometry and it is just using torque to yield tightening. It is also possible that the specs for the torque to yield were not quite correct, and therefore it is possible that tightened to a lower torque they would have been fine.
I've developed torque to yield for bolts in my job ( torque + an angle, such as 90 degrees) and one thing you never have is a the absolute worse case condition. Bolt geometry on minimum, internal thread on maximum, bolt at minimum hardness, and the most important - the finish having the lowest coefficient of friction it will ever have.
It is also interesting to note that "rod bolt failure" on this engine are on #3 cylinder. That means either #3 exerts more stress than the others (unlikely) or there something else going on, like oil starvation or bearing seizing, etc. that then creates a high stress causing the bolt to fail.
If I had a customer come to me and say it's the bolt's fault and it's used in multiple other places w/o problems, then let's take a look at the application.
But it always the bolt's fault.... |
I'd have to agree with you. It almost seems that the whole "rod bolt failure issue" might have a lot of internet propaganda behind it. Come to think of it I've never seen a rod bolt fail on one of these. Maybe some with more years wrenching on them have, however after asking around to those that have, it seems like the deer in the head light look is the common response. Maybe if someone reused the rods and retorqued them I could see it happening but for these to break without ever having been touched since leaving the factory seems to be a stretch (pun intended)
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
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| Posted: Thu Jan 16, 2020 11:09 pm Post subject: Re: Rod stretch bolt ID? |
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| Trevor P wrote: |
| vanagonjr wrote: |
Yes, good points Wildthings. I know people call them stretch bolts, and even manuals call them that at times, but really it is (likely) a standard bolt geometry and it is just using torque to yield tightening. It is also possible that the specs for the torque to yield were not quite correct, and therefore it is possible that tightened to a lower torque they would have been fine.
I've developed torque to yield for bolts in my job ( torque + an angle, such as 90 degrees) and one thing you never have is a the absolute worse case condition. Bolt geometry on minimum, internal thread on maximum, bolt at minimum hardness, and the most important - the finish having the lowest coefficient of friction it will ever have.
It is also interesting to note that "rod bolt failure" on this engine are on #3 cylinder. That means either #3 exerts more stress than the others (unlikely) or there something else going on, like oil starvation or bearing seizing, etc. that then creates a high stress causing the bolt to fail.
If I had a customer come to me and say it's the bolt's fault and it's used in multiple other places w/o problems, then let's take a look at the application.
But it always the bolt's fault.... |
I'd have to agree with you. It almost seems that the whole "rod bolt failure issue" might have a lot of internet propaganda behind it. Come to think of it I've never seen a rod bolt fail on one of these. Maybe some with more years wrenching on them have, however after asking around to those that have, it seems like the deer in the head light look is the common response. Maybe if someone reused the rods and retorqued them I could see it happening but for these to break without ever having been touched since leaving the factory seems to be a stretch (pun intended) |
I have owned three Vanagons as daily drivers.
-The 91 bought new was taken out of service because the rod bolts were stretching which was causing low oil pressure, mileage ~180K
-The 87 Syncro I bought from my family's doctor needed an engine rebuilt because one of the rod bolts had snapped at ~150K miles.
-The 83 1/2 with a 1.9L WBXer, which was an extremely abused car when I bought it, had very high miles on the engine, the odometer having stopped at something like 280K miles. I put another 75K on it before taking the engine out of service, no problems with the bottom end. |
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bobhill8
Samba Member
Joined: June 09, 2017
Posts: 736
Location: MA
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| Posted: Fri Jan 17, 2020 5:15 am Post subject: Re: Rod stretch bolt ID? |
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This is just one data point, but I have a receipt from 1996, long before I owned my 86.
"Connecting rod came through engine block".
Can't imagine how the PO felt about that with 60 K on the rig.
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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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| Posted: Fri Jan 31, 2020 11:27 am Post subject: Re: Rod stretch bolt ID? |
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Has anyone ever used the rebuilt rods Aircooled.net sells? They say they replace the bolts but don’t indicate which kind. Sent an email to them but yet to get an answer.
http://vwparts.aircooled.net/Waterboxer-Connecting...n-rods.htm
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17121
Location: Retired South Florida
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| Posted: Fri Jan 31, 2020 12:41 pm Post subject: Re: Rod stretch bolt ID? |
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No idea, but Van Café lists brand new OE connecting rods for a few dollars more.
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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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| Posted: Fri Jan 31, 2020 1:09 pm Post subject: Re: Rod stretch bolt ID? |
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| MarkWard wrote: |
| No idea, but Van Café lists brand new OE connecting rods for a few dollars more. |
The new Vancafe ones use the same torque to yield bolts that everyone seems so scared of.
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
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| Posted: Fri Jan 31, 2020 1:47 pm Post subject: Re: Rod stretch bolt ID? |
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| Trevor P wrote: |
| MarkWard wrote: |
| No idea, but Van Café lists brand new OE connecting rods for a few dollars more. |
The new Vancafe ones use the same torque to yield bolts that everyone seems so scared of. |
Maybe worth a call to see if they still offer rebuilt rods. |
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Trevor P
Samba Member
Joined: January 21, 2004
Posts: 863
Location: Saskatoon, SK, Canada
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| Posted: Tue Feb 18, 2020 4:41 pm Post subject: Re: Rod stretch bolt ID? |
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For those interested in the ones from Aircooled.net, John got back to me and confirmed that they are new 1.9L style non stretch bolts in these rebuilt rods. I see they have updated the description and are calling them 1.9L rods now.
http://vwparts.aircooled.net/Waterboxer-Connecting...ds-1.9.htm
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53 Canadian standard oval
56 Wolfsburg PG/SG
57 Oval, 2332 & Berg 5
70 911T
91 Westy |
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