Stuey and Frank.  Thanks for coming in on this.  Stuey, I hadn't seen the ARP catalog with the Tech. installation info.  JM's stud and bolt info is available on his web in the INFORMATION CENTER listing under the heading 'Installation Instructions'.  After that page opens, click the ninth topic down from the top, 'ARP Main Cap Fasteners'.  I couldn't put a link here that would open.

Frank's concern on drilling the main cap webbing holes deeper is akin to my own.  By simply substituting studs for bolts without increasing the thread depth, can I skip the drilling and tapping and accomplish adequate hold down with decreased likelihood of cracking in the web area because of how a stud works compared to a bolt?  Yes, the ARP studs would perhaps need to be shortened slightly, but I could do that on a lathe or with an abrasive sanding belt or disc.

On the pre-April '59 y-blocks' driver's side oil galley, there is NOT a lot of additional material that can be removed without breaking through into the main bearing feed galley.  I've used an extended length two lip end mill for drilling in the past to avoid the point of a drill bit breaking through.  When the point of a drill bit does JUST break into the oil galley, it can leave a knife edge thickness that looks prone to potentially breaking off and traveling.  

John, The Hoosier Hurricane was an advocate of the increased thread length as THE means to prevent web cracks in the 312s.  I want to do it right, but I don't like the drilling!

Regards,


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Hi Frank
I was not suggesting you do any drilling just stating engineering practice. If you have more thread engagement  than 1.5 times bolt diameter that's a bonus.
Perhaps Ted or John could say if you can manage with less thread engagement if using studs as opposed to bolts?
Johns web site under "assembly errors" is interesting reading.
Hope you are keeping well .
Wishing everyone on the site a Merry Christmas and a Happy Prosperous New Year. 
stuey

Stue 
         You'll want to be careful not to go too deep. The 312 blocks had problems cracking in that area. I'd let Ted or John Mummert address this to tell you how deep to go, if at all.

Frank/Rebop

Bristol, In ( by Elkhart) 

minimum thread engagement is  I 1/2 times thread diam. more the better. studs hand tight only.
http://arpcatalog.com/?src=home#50
stuey

I haven't used main bearing cap studs instead of bolts before.  On the pre-April '59 y-block engine blocks with their main cap bolts having a shorter length of thread into the block, should I make the time to increase the depth of the main cap bolt holes and use a bottoming tap before using ARP studs as I have done previously when using ARP bolts? 

NOTE:  In going through the engine, I am having the mains line honed, so I'm not trying to cut corners.  The question is raised by the owner's planned use of the engine not being of a performance nature.

Thanks for any input you might have on using the ARP studs instead of bolts.   


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York