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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Sat Oct 12, 2019 6:51 pm Post subject: 94’s oor |
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I had my 94 long cylinders machines down to the length I need. Unfortunately this introduced some oor at the bottom of the cylinders. I don’t have it all mocked up yet, but it appears the oor is where the skirt will ride, but not the rings. The Bentley says oor should be less than 0.01mm, but is this just for the ring area? The clearance for cylinder/piston is stated as 0.04-0.06 with a wear limit of 0.20. My piston skirts measure 93.90. The oor measures -0.06 to +0.025.
_________________ 1972 Karmann Ghia |
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bugguy1967 Samba Member
Joined: January 16, 2008 Posts: 4338 Location: Los Angeles, CA 90016
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Posted: Sat Oct 12, 2019 9:57 pm Post subject: Re: 94’s oor |
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The roundness of your barrels doesn't mean much until they're torqued-up in the case. As long as your running clearance is adequate, run it. If you want them really round, make a jig that remembles the case to clamp your barrels and hone them round. _________________ "A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine" |
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jpaull Samba Member
Joined: February 22, 2005 Posts: 3456 Location: Paradise, Ca
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Posted: Sat Oct 12, 2019 10:43 pm Post subject: Re: 94’s oor |
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Its good your checking😁 |
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Bad bug Samba Member
Joined: March 11, 2006 Posts: 1119 Location: Jamaica
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Posted: Sun Oct 13, 2019 1:43 am Post subject: Re: 94’s oor |
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Always clean all your parts before you measure and use a torque plate to torque the cylinders in before you measure them. |
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andy198712 Samba Member
Joined: December 05, 2010 Posts: 1209 Location: Cornwall - UK
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Posted: Sun Oct 13, 2019 3:49 am Post subject: Re: 94’s oor |
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what caused them to go OOR do you think? the cutting or clamping? _________________
Alstrup wrote: |
I like 5,5inchers in the rear at least. |
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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Sun Oct 13, 2019 10:30 am Post subject: Re: 94’s oor |
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Does anyone have any pictures of a torque plate? _________________ 1972 Karmann Ghia |
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HotStreetVw Samba Member
Joined: October 03, 2004 Posts: 871 Location: Wild West
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Posted: Sun Oct 13, 2019 10:37 am Post subject: Re: 94’s oor |
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Run it and stop stressing out. The piston skirt isn’t round either. _________________ 4inBhore
50 Split - 2724cc NA. Haltech injected
62 Notchback - 2542cc Turbo WIP |
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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Sun Oct 13, 2019 11:18 am Post subject: Re: 94’s oor |
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andy198712 wrote: |
what caused them to go OOR do you think? the cutting or clamping? |
Removal of material caused it, cause they weren’t clamped on this end. _________________ 1972 Karmann Ghia |
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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Sun Oct 13, 2019 11:19 am Post subject: Re: 94’s oor |
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HotStreetVw wrote: |
Run it and stop stressing out. The piston skirt isn’t round either. |
Good enough for me! Was hoping a builder would tell me that _________________ 1972 Karmann Ghia |
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Bad bug Samba Member
Joined: March 11, 2006 Posts: 1119 Location: Jamaica
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Posted: Sun Oct 13, 2019 4:47 pm Post subject: Re: 94’s oor |
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Onceler wrote: |
Does anyone have any pictures of a torque plate? |
https://www.getlowered.com/jims-cylinder-torque-plates-for-harley-m8/
This is one for a harley engine. I am going to use old heads cut to 94mm and one half of my oxy block ( case has to be decked ) as a torque plate setup.. |
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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Sun Oct 13, 2019 5:11 pm Post subject: Re: 94’s oor |
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Thanks. Do you just torque to 23 ft-lbs.? _________________ 1972 Karmann Ghia |
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Bad bug Samba Member
Joined: March 11, 2006 Posts: 1119 Location: Jamaica
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Posted: Sun Oct 13, 2019 5:18 pm Post subject: Re: 94’s oor |
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everything i am torquing will be done in stages. |
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Bad bug Samba Member
Joined: March 11, 2006 Posts: 1119 Location: Jamaica
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Posted: Sun Oct 13, 2019 5:19 pm Post subject: Re: 94’s oor |
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You could make a torque plate for yourself if you wanted to. |
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earthquake Samba Member
Joined: January 10, 2008 Posts: 3984 Location: SANDY VALLEY, NEVADA
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Posted: Tue Oct 15, 2019 11:41 am Post subject: Re: 94’s oor |
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Mixing Mt. Dew and Heineken would make me OOR too!
eQ _________________ 74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison] |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Tue Oct 15, 2019 4:39 pm Post subject: Re: 94’s oor |
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HotStreetVw wrote: |
Run it and stop stressing out. The piston skirt isn’t round either. |
say it aint so!!! so..the earth is flat and the skirts are.....blowing in the brezze!!!.... many skirts are quite far from round.others are close to being round... the lower end of the cylinder shouldent affect it much depending on how&where it is outa round when torqued, but just torqueing isant the all telling situation.... a goof few heat cycles from running will also change the shape. howmuch well that depends on a few things,like cylinder material, thickness,ageing, hardness and how hot it gets or dosent get. but for a vw if your clearance aint too tight your probably good. some engines when bored&honed to "size" without tqplates and then adding the torqued head the bore can be distorted to a interfearance fit.....as in the piston and cylinder will soon become 1... not good. for modern china cylinders,whoo knows what your gonna get. checking is a good idea. honeing with plates is a good idea. if you do neither atleast knock the tooth off the factory rough jagged debries filled hone job the cylinders come with. |
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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Tue Oct 15, 2019 5:19 pm Post subject: Re: 94’s oor |
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Hmmm, maybe I can heat them in a oven several times. Say like to 300 degrees and check again. I’m really in no big hurry to get this built due to winter coming _________________ 1972 Karmann Ghia |
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67rustavenger Samba Member
Joined: February 24, 2015 Posts: 9663 Location: Oregon
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Posted: Tue Oct 15, 2019 5:38 pm Post subject: Re: 94’s oor |
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Onceler wrote: |
Hmmm, maybe I can heat them in a oven several times. Say like to 300 degrees and check again. I’m really in no big hurry to get this built due to winter coming |
And before you know it. The spring driving season will be upon you. I'm not saying hurry up. But work through the cold winter months. And be ready for spring.
I started a build at XMas two years ago. I didn't get the build completed in time for the spring driving season.
Just sayin!
Good Luck _________________ I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!
There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo! |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed Oct 16, 2019 1:31 pm Post subject: Re: 94’s oor |
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they should be heet cycled under load....as in torqued. |
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Onceler Samba Member
Joined: May 28, 2010 Posts: 1646 Location: Indiana
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Posted: Thu Oct 31, 2019 8:07 pm Post subject: Re: 94’s oor |
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Ok, so RWK was kind enough to send me torque plates he made (side note: RWK is the man if you need machine work done)
So I torqued a cylinder to 18 ft/lbs. and put it and a piston in the oven to 450 degrees F. Afterward, I measured the bore, the oor didn’t change, but the overall size increased by 0.15. When I measured the piston, the skirt grew by 0.25
I found this interesting, but assume the piston never really heats up to this temp. Otherwise I’d imagine we’d see a lot of stuck motors.
Anyway, I’m planning on having the cylinders honed back to round using the torque plates and hopefully a more ideal surface finish. Planning on using total seal rings. _________________ 1972 Karmann Ghia |
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Mr. OGPaint Samba Member
Joined: September 24, 2010 Posts: 821 Location: Oregon
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Posted: Thu Oct 31, 2019 8:34 pm Post subject: Re: 94’s oor |
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0.01mm seems like an incredibly close tolerance for Out Of Round. I have nothing else to add. Good luck. _________________ https://instagram.com/mr.ogpaint
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Patrick Hall |
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