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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 7:12 am Post subject: New cam binding - Cam bores reamed back to STD |
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Good morning everyone!
First off, Thank you for your replies or if you can direct me to a thread with more info! I've searched and haven't found much in the past few weeks.
I just recently had my AS41 case for my '71 bus sent off to Painter's Grinding in Denver to have the cam bores reamed back to standard (the old and new cam were freezing up when I torqued the case.
I got the case back and put in a new set of double thrust Mahle cam bearings and the new cam along with a little assembly lube. I already put the new cam in, hit it once fore and aft, and got the thrust surface sanded slightly for endplay.
I torque down the 6 nuts to 25ftlb and the new cam, again, freezes in the case. I let off the bottom middle nut slightly and it will free up. I put the old cam in with the new bearings and everything spins fine. The old cam is is decent shape with no pitting or wear on the lobes.
My question.. is there anything I can do to the new cam to stop it from binding? As far as I can tell the case isn't warped or cracked. Would using the old cam with the new bearings be OK?
-Scott _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Ohio Tom Samba Member
Joined: February 09, 2006 Posts: 1657 Location: Marshallville Ohio
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Posted: Mon Oct 12, 2020 7:41 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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install and torque all of the case nuts. the case won't settle down until torqued.
mag cases move alot with age.
Apart, they are no where near flat.
Only consder full torque to be any sort of reference.
Measure the OD of the cam journals to see if the new one is bigger than the old one.
A slightly tight cam is not that big of a deal. It won't lock up or anything like that.
It will wear-in as it were.
Also, you should Never tap on a cam. They are cast and will break like glass. |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Mon Oct 12, 2020 7:42 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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tweakhx wrote: |
Good morning everyone!
First off, Thank you for your replies or if you can direct me to a thread with more info! I've searched and haven't found much in the past few weeks.
I just recently had my AS41 case for my '71 bus sent off to Painter's Grinding in Denver to have the cam bores reamed back to standard (the old and new cam were freezing up when I torqued the case.
I got the case back and put in a new set of double thrust Mahle cam bearings and the new cam along with a little assembly lube. I already put the new cam in, hit it once fore and aft, and got the thrust surface sanded slightly for endplay.
I torque down the 6 nuts to 25ftlb and the new cam, again, freezes in the case. I let off the bottom middle nut slightly and it will free up. I put the old cam in with the new bearings and everything spins fine. The old cam is is decent shape with no pitting or wear on the lobes.
My question.. is there anything I can do to the new cam to stop it from binding? As far as I can tell the case isn't warped or cracked. Would using the old cam with the new bearings be OK?
-Scott |
Just to be clear.....you rap the cam fore and aft....after.....you torque the case. Torqueing the case misaligns the cam bearing shells at their contact edges as the case crushes them. Rapping it fore and aft re-sets this.
So....rapping it fore and aft BEFORE you have complete crush does not do it. Ray |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Mon Oct 12, 2020 8:07 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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all the above and polish the cam journels, most are too ruff... aswell as you need to deburr the lobes edges. |
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[email protected] Samba Member
Joined: August 15, 2002 Posts: 4394 Location: Brew City
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Posted: Mon Oct 12, 2020 8:09 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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tweakhx wrote: |
Good morning everyone!
First off, Thank you for your replies or if you can direct me to a thread with more info! I've searched and haven't found much in the past few weeks.
I just recently had my AS41 case for my '71 bus sent off to Painter's Grinding in Denver to have the cam bores reamed back to standard (the old and new cam were freezing up when I torqued the case.
I got the case back and put in a new set of double thrust Mahle cam bearings and the new cam along with a little assembly lube. I already put the new cam in, hit it once fore and aft, and got the thrust surface sanded slightly for endplay.
I torque down the 6 nuts to 25ftlb and the new cam, again, freezes in the case. I let off the bottom middle nut slightly and it will free up. I put the old cam in with the new bearings and everything spins fine. The old cam is is decent shape with no pitting or wear on the lobes.
My question.. is there anything I can do to the new cam to stop it from binding? As far as I can tell the case isn't warped or cracked. Would using the old cam with the new bearings be OK?
-Scott |
What kind of cam and what kind of bearings? Unless it a SUPER HIGH performance build, I never use double thrust cam bearings. IF you do, you have to sand on the thrust flange. I'm not saying it isn't possible but I would give you a better chance of winning the lottery than the cam bore being too small on a new case. _________________ Please "LIKE" us on facebook to see what we are working on.
https://www.facebook.com/mofoco?ref=ts&fref=ts
www.mofoco.com
Cylinder Head Reference Sheet |
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 8:34 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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UK Luke 72 wrote: |
Remove the middle bearing and but a DTI on the centre bearing to see if the cam is bent. |
Sorry, DTI? _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 8:35 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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Ohio Tom wrote: |
install and torque all of the case nuts. the case won't settle down until torqued.
Also, you should Never tap on a cam. They are cast and will break like glass. |
I did think of this, but haven't had a chance. I will try that tonight. Thanks! _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 8:36 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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raygreenwood wrote: |
Just to be clear.....you rap the cam fore and aft....after.....you torque the case. Torqueing the case misaligns the cam bearing shells at their contact edges as the case crushes them. Rapping it fore and aft re-sets this.
So....rapping it fore and aft BEFORE you have complete crush does not do it. Ray |
Thank you Ray for explaining why this is done. I will try this tonight. _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 8:36 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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mark tucker wrote: |
all the above and polish the cam journels, most are too ruff... aswell as you need to deburr the lobes edges. |
Will do, thanks! _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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Lingwendil Samba Member
Joined: February 25, 2009 Posts: 3987 Location: Antioch, California, a block from the hood
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Posted: Mon Oct 12, 2020 8:38 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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tweakhx wrote: |
raygreenwood wrote: |
Just to be clear.....you rap the cam fore and aft....after.....you torque the case. Torqueing the case misaligns the cam bearing shells at their contact edges as the case crushes them. Rapping it fore and aft re-sets this.
So....rapping it fore and aft BEFORE you have complete crush does not do it. Ray |
Thank you Ray for explaining why this is done. I will try this tonight. |
+1
also, if you do this usually you'll see the thrust surface is in spec, some people sand it before doing this and end up with too much fore/aft play. _________________ 73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!
Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884
Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0
Need replacement filters for original Kadron aircleaners? WIX #42087 is a perfect fit, as is Napa Gold #2087! |
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 8:42 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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[email protected] wrote: |
What kind of cam and what kind of bearings? Unless it a SUPER HIGH performance build, I never use double thrust cam bearings. IF you do, you have to sand on the thrust flange. I'm not saying it isn't possible but I would give you a better chance of winning the lottery than the cam bore being too small on a new case. |
I should have stated in my original post that this is a 100% stock rebuild. The cam is new from Jbugs (I can't remember the brand name at the moment, it came in a red triangular box.) and the bearings are Mahle. I read using double thrust is just extra "insurance." Plus I had already tried two sets of Silverline bearings and neither worked (this was before getting the cam bores reamed, but they seemed to fit tighter anyway)
The thrust surfaces are sanded. I used fine wet sandpaper. I will try a few of the forementioned things and will update this thread.
Thanks! _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 8:46 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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Lingwendil wrote: |
+1
also, if you do this usually you'll see the thrust surface is in spec, some people sand it before doing this and end up with too much fore/aft play. |
I read about this. I guess where I failed is where Ray stated the case has to be torqued first. I hope I haven't sanded too much off! _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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[email protected] Samba Member
Joined: August 15, 2002 Posts: 4394 Location: Brew City
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Posted: Mon Oct 12, 2020 8:51 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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tweakhx wrote: |
[email protected] wrote: |
What kind of cam and what kind of bearings? Unless it a SUPER HIGH performance build, I never use double thrust cam bearings. IF you do, you have to sand on the thrust flange. I'm not saying it isn't possible but I would give you a better chance of winning the lottery than the cam bore being too small on a new case. |
I should have stated in my original post that this is a 100% stock rebuild. The cam is new from Jbugs (I can't remember the brand name at the moment, it came in a red triangular box.) and the bearings are Mahle. I read using double thrust is just extra "insurance." Plus I had already tried two sets of Silverline bearings and neither worked (this was before getting the cam bores reamed, but they seemed to fit tighter anyway)
The thrust surfaces are sanded. I used fine wet sandpaper. I will try a few of the forementioned things and will update this thread.
Thanks! |
Well, not to rain on your parade BUT I don't like and refuse to use those cams or cam bearings in my builds. I use only silverline cam bearings and stock German reground cams. I just don't like the quality of the new Chinese or Brazil cams compared to a reground German. You may have to debur on the thrust surface of the cam blank itself. Take note, however, that the German reground cams I use have only been ground one time and still have a very large base circle. I don't use cams that have a base circle that is the same diameter as the cam itself. _________________ Please "LIKE" us on facebook to see what we are working on.
https://www.facebook.com/mofoco?ref=ts&fref=ts
www.mofoco.com
Cylinder Head Reference Sheet |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3227 Location: Rapid City, SD
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Posted: Mon Oct 12, 2020 9:23 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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Let me know if you need any help with this. I am in Rapid City and I have bearings and a cam bore tool. Never had one I couldn't get sorted out.
Brian _________________ www.type-emotorsports.com |
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 9:31 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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Brian_e wrote: |
Let me know if you need any help with this. I am in Rapid City and I have bearings and a cam bore tool. Never had one I couldn't get sorted out.
Brian |
Thank you very much Brian! I will let you know what I find out tonight. _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7179 Location: Videbaek Denmark
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Posted: Mon Oct 12, 2020 10:28 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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[email protected] wrote: |
What kind of cam and what kind of bearings? Unless it a SUPER HIGH performance build, I never use double thrust cam bearings. |
Kinda funny to see how things are done different here and there. I hardly ever use anything else than double trust bearings
ABSOLUTELY NOT! The first thing to do is give the cam a rap front and rear sort of to set the bearing. If that isnt enough you can do it once more. If that still doesnt give you the clearance you need, THEN you can sand the bearings slightly, but only then. Done this way the tolerance stays instead of wander off immesiately after the engine is started and boken in.
[email protected] wrote: |
I'm not saying it isn't possible but I would give you a better chance of winning the lottery than the cam bore being too small on a new case. |
I do not know with those repro stock cams. I have never used one. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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GARRICK.CLARK Samba Member
Joined: June 30, 2012 Posts: 1267 Location: Lancashire UK
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Posted: Mon Oct 12, 2020 10:56 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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I use doubles here too, it's silly not too. It's an upgrade with no down side too it. 1st I'd be fitting the crank and checking if that spins on a closed case. If the crank won't spin either, the case has warped. For a quick test put an engineers straight edge across the main 6 case mating surfaces and look for day light on the centre main saddle pad. |
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tweakhx Samba Member
Joined: April 11, 2012 Posts: 156 Location: South Dakota
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Posted: Mon Oct 12, 2020 11:06 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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GARRICK.CLARK wrote: |
I use doubles here too, it's silly not too. It's an upgrade with no down side too it. 1st I'd be fitting the crank and checking if that spins on a closed case. If the crank won't spin either, the case has warped. For a quick test put an engineers straight edge across the main 6 case mating surfaces and look for day light on the centre main saddle pad. |
The crank spins nice and smooth. I'll have to pick up a nice straight edge to check that. Thanks! _________________ 1968 Diamond Blue FI Fastback
1969 Diamond Blue FI Fastback Auto
1971 Pastel White Westfalia
2007 GTI
2012 Beetle 2.5L
endle wrote: |
Ever since I bought a vw I have not been able to keep my fingernails clean.
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GARRICK.CLARK Samba Member
Joined: June 30, 2012 Posts: 1267 Location: Lancashire UK
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Posted: Mon Oct 12, 2020 11:14 am Post subject: Re: New cam binding - Cam bores reamed back to STD |
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Has a fresh align bore job been done or at least checked by a vw machine shop. How's the end float.
All bearings need a slight crush fit and the flywheel bearing should not move back and forth in its fully fitted position. With dowel fitted
There's a lot of check n prep work on a case, and a lot that can go wrong. |
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