Topic: main studs Q?

[Don R]

 On an engine with main studs how do you seal the oil in? The motor I took apart appeared to have teflon tape wrapped around the studs under the nuts and washers. I wondered about snug fitting copper washers under the stud washers.

[slikwilli420]

You're going to get lots of opinions on this but trust mine as I have dealt with this a variety of ways. I used tape and Honda bond and all kinds of crap then I found the holy grail. Yamaha Banshee head nuts. Available in stainless or titanium, they are extra long capped nuts with a torque spec for the banshee of 28ft/lbs. I put them on both race bikes and not a drop of oil to be found.

[Don R]

 Thanks, exactly the kind of tip I was looking for.
  While removing the black paint and rat pee residue I realized the entire top rear motor mount has been welded back on. It appears I'm moving all of these studs to another case.

[slikwilli420]

Thanks, exactly the kind of tip I was looking for.
  While removing the black paint and rat pee residue I realized the entire top rear motor mount has been welded back on. It appears I'm moving all of these studs to another case.

Sometimes that's how the cookie crumbles. I'm also a fan of just skimming each nut surface on the bottom cases with an end mill. It's amazing how out of square those surfaces can be. Just enough to get a uniform base for the nut to rest on.

[Don R]

 Thanks.

[Jerry Rxman Griffin aka MuthaF'er]

I use case sealer carefully on the main bearing saddles and the same washers used on the head under the nut. On the rare leak at the bottom I will remove the nut and apply case sealer in the hole around the stud threads and on the washer. I'd be worried that the soft copper washers would eventually crush more and leak and not hold the torque.

[Don R]

  Thanks, I got the stock studs out of the welded block and the heavy duty ones out also. I remember something about torquing them into the block.
  I think ARP said not to torque the studs into my big block chevy, just loctite hand tight and 24 hours to set. Maybe the difference is water jackets.

[Tracksnblades1]

I’d follow SW420’s lead here..

Since we’re following his lead, let’s mention the other heteronym “lead”
the bad for you “lead” that plumbers are familiar with.

Anyway JohnDeere used lead washers successfully on old Johnny Putts for years.
Under their head stud nuts and rock arm head stud nuts. Keeping the oil and antifreeze
from swapping places or mixing.. Side benefits, no galling, stripping, seizing, or damage
to the head surface.. 😇

[MRieck]

  Thanks, I got the stock studs out of the welded block and the heavy duty ones out also. I remember something about torquing them into the block.
  I think ARP said not to torque the studs into my big block chevy, just loctite hand tight and 24 hours to set. Maybe the difference is water jackets.

Exactly. Measure the height....that's it.

[Tracksnblades1]

  Thanks, I got the stock studs out of the welded block and the heavy duty ones out also. I remember something about torquing them into the block.
  I think ARP said not to torque the studs into my big block chevy, just loctite hand tight and 24 hours to set. Maybe the difference is water jackets.

Ole Smokey used to write the same in his engine building books.
Adding to set the head on deck type studs. Applying the lock tight on
studs, finger tight into the deck (open or blind), and snugging head stud nut up,
 to ensure the lock tight set holding the stud perpendicular to the deck.  Claiming
the generous thread engagement clearances would allow the studs to pull up and
 set perfectly perpendicular in the deck. Even if the deck holes weren’t drilled so.

I’ve used this technique, but always set the head on first and installed the studs one
at a time. Always afraid the lock tight would set before I could get them (32) pulled up
straight with the nut. It’ll bring your leak down under 3%, especially if you had a few
studs splayed out scraping the cylinder head holes on the way down..wrecking that top 1 inch
of the bore when torquing..

[Don R]

 I worded that poorly, I got the stock studs out of the "new" crankcase and the APE studs out of the welded crankcase. But you guys figured that out. I wore out two head nuts before I went to 13mm hardware store parts. The HD studs came out with a light duty impact driver once they were broken loose.
 
 Smokey had a lot of secrets he was willing to share. He was probably even ahead of Garlits in inventiveness. Garlits FED streamliner body was just hiding his 1" fuel lines. Everyone else was copying the body without knowing why.

[Tracksnblades1]

Indeed,

I still remember when ARP directions recommended
Torquing studs 10lbft. Requiring some to drill their expensive
Heads the next size just to get them to go down.😳

420’s mention of lightly spot facing is a good practice even
just to verify. There’s always that dreaded Monday or Friday
engine….🤔