Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts New!  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
8mm Head Studs vs. 10mm Head Studs
Page: 1, 2  Next
Forum Index -> Performance/Engines/Transmissions Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
dzrtdave
Samba Member


Joined: April 25, 2007
Posts: 49
Location: Page Springs , AZ
dzrtdave is offline 

PostPosted: Tue Feb 02, 2010 9:41 pm    Post subject: 8mm Head Studs vs. 10mm Head Studs Reply with quote

So a quick question - I have 2 cases, one that is STD line bore, 8mm head studs and one 1.5mm line bore not STD thrust 10mm studs. 9.5:1 CR 2332, VZ15 cam CB heads. STD 84mm crank. Which case would you use? Machine work is completed and ready on both cases. Gotta buy a set of bearings anyway so ...

dzrtdave Shocked Confused
Back to top
View user's profile Send private message Gallery Classifieds Feedback
jfats808
Samba Member


Joined: December 10, 2007
Posts: 5022
Location: oahu hawaii
jfats808 is offline 

PostPosted: Tue Feb 02, 2010 9:59 pm    Post subject: Reply with quote

If both cases are exactly the same condition, I would use the non cut one. Especially for a big build, its a personal preference to start with a newer or in this case, the one that has less machine life taken from it. I always prefer to use 8mm head studs on my engines.
_________________
2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125

Rockstar Suzuki wrote:

You might as well put 10 year build in your bullshit sig, as it will NEVER run. Also your a dick

You can always learn something new, even from a fool.
Check your oil levels routinely!
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
dzrtdave
Samba Member


Joined: April 25, 2007
Posts: 49
Location: Page Springs , AZ
dzrtdave is offline 

PostPosted: Tue Feb 02, 2010 10:08 pm    Post subject: Reply with quote

That was my lean, I was just questioning the durability of the smaller studs. I'm not turboing it or running 14:1 CR, Just a grocery getter Laughing
Back to top
View user's profile Send private message Gallery Classifieds Feedback
LeviMan2001
Samba Post Whore


Joined: April 11, 2009
Posts: 3855
Location: Alaska
LeviMan2001 is offline 

PostPosted: Tue Feb 02, 2010 10:26 pm    Post subject: Reply with quote

jfats808 wrote:
I always prefer to use 8mm head studs on my engines.


I am curious to know the reasons behind that Confused That seems to make absolutely no sense to me.
_________________
http://www.thesamba.com/vw/forum/viewtopic.php?t=366056 - My '73 Super Build. 2332cc, 16" Fuchs
Back to top
View user's profile Send private message Gallery Classifieds Feedback
bugninva
Samba Member


Joined: December 14, 2004
Posts: 8858
Location: sound it out.
bugninva is offline 

PostPosted: Tue Feb 02, 2010 11:02 pm    Post subject: Reply with quote

LeviMan2001 wrote:
jfats808 wrote:
I always prefer to use 8mm head studs on my engines.


I am curious to know the reasons behind that Confused That seems to make absolutely no sense to me.


because when you are talking about stock cases, it's because they not only work, but have factory case savers... the 10mm cases did not have case savers...
_________________
[email protected] wrote:
With a show of hands, who has built over 1000 engines in the last 25 years? Anyone?


GEX has. Just sayin
Back to top
View user's profile Send private message Classifieds Feedback
Type 5 Joe
Banned


Joined: January 18, 2003
Posts: 1795
Location: Oregon
Type 5 Joe is offline 

PostPosted: Tue Feb 02, 2010 11:28 pm    Post subject: Reply with quote

As VW progressed in their development of the Type I engine, they changed from 10 to 8mm headstuds.

The horsepower ratings, and heavier loads to push were increasing during this era also.

VW figured out that better engine case alloys and smaller high quality studs combined with case savers (eventually), reacted better and was more reliable than the old Ideas.

I always use 8mm (genuine original VW) studs and never have any problems.

One time, back in the early 80's (when I was much younger) I had some rain water leak into one of my 48 Dellortos.... 12.5 to 1 compression dry-sumped 2180.

When I went to crank the engine, I knew there was a problem. Pulled the engine, tore it down... Checked every thing, and replaced the headstuds on one side.

The 8mm studs had "stretched" and saved my ass.
_________________
If you would like to contact me, just email through one of my ads on here...

I don't use the P.M. service on here.
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Alan_U
Samba Member


Joined: July 10, 2004
Posts: 1762
Location: Vancouver, BC Canada
Alan_U is offline 

PostPosted: Wed Feb 03, 2010 1:55 am    Post subject: Reply with quote

For your application I'd say 8mm and call it a day. Case savers with 8mm will work absolutely fine. 10mm gets tighter in fitment (not a big deal) however the 8mm has more ease of assembly.

I have used bugpack 8mm on my 2332 and no cutting was required. With the same studs I've ran 11.90's-12.00's for years (many of those years using the car as a fair weather pumpgas daily driver).

Your current case should have case savers for 8mm studs. I'd keep things simple since it doesn't sound like your not building a turbo.
_________________
11.92sec pump gas true daily driver. Who says it cant be done.

No more time for VW's.......
Back to top
View user's profile Send private message Visit poster's website Classifieds Feedback
donmurray
Samba Member


Joined: December 30, 2008
Posts: 841
Location: Frisco Texas
donmurray is offline 

PostPosted: Wed Feb 03, 2010 9:48 am    Post subject: Reply with quote

There's an argument that the correct size bolt or stud will stretch when the correct torque is applied. The stretch keeps the parts in compression and maintains a more constant torque when the parts (cylinder & head) expand under heat. A bigger bolt or one made with different material might not stretch as much as needed. Could put too much load on the threads (or parts) as the parts expand.
_________________
74 Ghia, with 2110 engine
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Sigurd
Samba Member


Joined: April 18, 2006
Posts: 2522
Location: Rockford, IL
Sigurd is offline 

PostPosted: Wed Feb 03, 2010 11:47 am    Post subject: Reply with quote

I had a dickens of a time clearancing my Mahle 94s for 8mm studs. I can't imagine hogging them out for 10s.

Last edited by Sigurd on Wed Feb 03, 2010 1:50 pm; edited 1 time in total
Back to top
View user's profile Send private message Gallery Classifieds Feedback
MinamiKotaro
Samba Member


Joined: July 18, 2008
Posts: 1039
Location: Somewhere in TN
MinamiKotaro is offline 

PostPosted: Wed Feb 03, 2010 12:57 pm    Post subject: Reply with quote

Sigurd wrote:
I had a dickens of a time clearancing my Mahle 94s for 9mm studs. I can't imagine hogging them out for 10s.


It's a pain in the ass.
_________________
1967 VW Beetle
2276cc
MegaSquirt-extra v3.57
Check out my ongoing story.
Back to top
View user's profile Send private message Classifieds Feedback
Matthew
Samba Member


Joined: January 29, 2004
Posts: 1630
Location: Eastern Tennessee
Matthew is offline 

PostPosted: Wed Feb 03, 2010 1:23 pm    Post subject: Reply with quote

The 10mm studs have a nasty habit of pulling out of the case. VW engineers solved that problem by going with the 8mm studs which can grow with the engine as it expands.
_________________
1965 Beetle sedan
Click to view image
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
MinamiKotaro
Samba Member


Joined: July 18, 2008
Posts: 1039
Location: Somewhere in TN
MinamiKotaro is offline 

PostPosted: Wed Feb 03, 2010 11:09 pm    Post subject: Reply with quote

Matthew wrote:
The 10mm studs have a nasty habit of pulling out of the case. VW engineers solved that problem by going with the 8mm studs which can grow with the engine as it expands.


Dad's 2110 pulled a couple of 8mm studs. These were high-quality chromoly studs, not cheap stuff. He put 10mm studs in and never had a problem from then on. Wasn't even that hot of an engine.

Throw 20+ psi of boost into the mix and I wouldn't trust 8mm studs at all. My 8mm studs were showing signs of stretch and I hadn't made that many passes. The oddball 9mm studs we found to replace them lasted a long time but they were getting stretched, too. My next engine will have 10mm studs.
_________________
1967 VW Beetle
2276cc
MegaSquirt-extra v3.57
Check out my ongoing story.
Back to top
View user's profile Send private message Classifieds Feedback
Matthew
Samba Member


Joined: January 29, 2004
Posts: 1630
Location: Eastern Tennessee
Matthew is offline 

PostPosted: Thu Feb 04, 2010 6:56 am    Post subject: Reply with quote

Matthew wrote:
The 10mm studs have a nasty habit of pulling out of the case. VW engineers solved that problem by going with the 8mm studs which can grow with the engine as it expands


MinamiKotaro wrote:
Dad's 2110 pulled a couple of 8mm studs. These were high-quality chromoly studs, not cheap stuff. He put 10mm studs in and never had a problem from then on. Wasn't even that hot of an engine.



I'd bet that the cromoly studs don't expand with the engine the way the genuine VW 8mm studs do and that's why the 2110 pulled studs. If they are pulling out of the block it's not because the studs are weak.
_________________
1965 Beetle sedan
Click to view image
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Type 5 Joe
Banned


Joined: January 18, 2003
Posts: 1795
Location: Oregon
Type 5 Joe is offline 

PostPosted: Thu Feb 04, 2010 7:14 am    Post subject: Reply with quote

Yes, use a sledgehammer if a hammer won't work....

If that doesn't do it, you can rent an industrial air compressor and a jack-hammer. I hear that they are considered "High Quality", not the "cheap stuff". Wink
_________________
If you would like to contact me, just email through one of my ads on here...

I don't use the P.M. service on here.
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
MinamiKotaro
Samba Member


Joined: July 18, 2008
Posts: 1039
Location: Somewhere in TN
MinamiKotaro is offline 

PostPosted: Thu Feb 04, 2010 9:08 am    Post subject: Reply with quote

Type 5 Joe wrote:
Yes, use a sledgehammer if a hammer won't work....

If that doesn't do it, you can rent an industrial air compressor and a jack-hammer. I hear that they are considered "High Quality", not the "cheap stuff". Wink


You can can your attitude. 8mm studs did not work for us. 10mm studs did.

Quote:
I'd bet that the cromoly studs don't expand with the engine the way the genuine VW 8mm studs do and that's why the 2110 pulled studs. If they are pulling out of the block it's not because the studs are weak.


The 8mm studs had stretched and been retorqued several times before they pulled. He was seeing signs of lifting heads. 10mm studs, no more problems.

10mm are stronger. Some people can benefit from them.
_________________
1967 VW Beetle
2276cc
MegaSquirt-extra v3.57
Check out my ongoing story.
Back to top
View user's profile Send private message Classifieds Feedback
Type 5 Joe
Banned


Joined: January 18, 2003
Posts: 1795
Location: Oregon
Type 5 Joe is offline 

PostPosted: Thu Feb 04, 2010 9:28 am    Post subject: Reply with quote

No attitude...

Maybe you need to read the original post.

This is not a Turbo thread.
_________________
If you would like to contact me, just email through one of my ads on here...

I don't use the P.M. service on here.
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
[email protected]
Samba Member


Joined: August 03, 2002
Posts: 12783
Location: Salt Lake City, Utah
john@aircooled.net is offline 

PostPosted: Thu Feb 04, 2010 11:01 am    Post subject: Reply with quote

If you needed 10mm headstuds "to prevent problems" in a car that ran 13s you should fix your ignition timing, of which you have WAY too much of. You don't even NEED 10mm headstuds until 9s, or MAYBE low 10s.

MinamiKotaro wrote:


You can can your attitude. 8mm studs did not work for us. 10mm studs did.

Quote:
I'd bet that the cromoly studs don't expand with the engine the way the genuine VW 8mm studs do and that's why the 2110 pulled studs. If they are pulling out of the block it's not because the studs are weak.


The 8mm studs had stretched and been retorqued several times before they pulled. He was seeing signs of lifting heads. 10mm studs, no more problems.

10mm are stronger. Some people can benefit from them.

_________________
It's just advice, do whatever you want with it!

Please do NOT send me Private Messages through the Samba PM System (I will not see them). Send me an e-mail to john at aircooled dot net

"Like" our Facebook page at
http://www.facebook.com/vwpartsaircoolednet
and get a 5% off code for use on one order for VW Parts ON OUR PARTS STORE WEBSITE, vwparts.aircooled.net
Back to top
View user's profile Send private message Send e-mail Visit poster's website Facebook Gallery Classifieds Feedback
bdkw1
Samba Member


Joined: December 08, 2008
Posts: 798
Location: SoCal
bdkw1 is offline 

PostPosted: Thu Feb 04, 2010 11:15 am    Post subject: Reply with quote

Matthew wrote:
I'd bet that the cromoly studs don't expand with the engine the way the genuine VW 8mm studs do and that's why the 2110 pulled studs. If they are pulling out of the block it's not because the studs are weak.


The difference expansion rates between chromoly and the stock head stud material is so small I highly doubt you would ever be able to measure it.
Back to top
View user's profile Send private message Classifieds Feedback
MinamiKotaro
Samba Member


Joined: July 18, 2008
Posts: 1039
Location: Somewhere in TN
MinamiKotaro is offline 

PostPosted: Thu Feb 04, 2010 4:51 pm    Post subject: Reply with quote

Type 5 Joe wrote:
No attitude...

Maybe you need to read the original post.

This is not a Turbo thread.


No attitude, eh? I stated our results with 8mm vs. 10mm. Rather than respond in any way, you made fun of me. That's attitude, and I doubt you'd have the balls to act like that face-to-face.
_________________
1967 VW Beetle
2276cc
MegaSquirt-extra v3.57
Check out my ongoing story.
Back to top
View user's profile Send private message Classifieds Feedback
Bajaman65
Samba Member


Joined: January 16, 2007
Posts: 469
Location: Borrego Springs
Bajaman65 is offline 

PostPosted: Thu Feb 04, 2010 5:29 pm    Post subject: Reply with quote

Quote:
One time, back in the early 80's (when I was much younger) I had some rain water leak into one of my 48 Dellortos.... 12.5 to 1 compression dry-sumped 2180.

When I went to crank the engine, I knew there was a problem. Pulled the engine, tore it down... Checked every thing, and replaced the headstuds on one side.

The 8mm studs had "stretched" and saved my ass.


I had about the same thing happen, 2387 10 to 1 with water in #1 cyl when the engine fired once and BANG. My 8mm studs stretched about .05 and the wrist pin on #1 bent .002". New bearing, studs and a set of pistons and I was away and running. I have never had a failure with good 8mm studs Wink
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Performance/Engines/Transmissions All times are Mountain Standard Time/Pacific Daylight Savings Time
Page: 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2020, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB