[QUOTE=Cape Codder;2254974]I have a question on the above statement. I don't understand the instructions of adding a small "O" ring on the nuts in a newly made engine! Why would you have to do that AND what does that do to the torque value on the nut?[/QUOTE
The following is from the builders Guide
The 3 main bearing studs that have nuts on the exterior (2 at main #1 and 1 at
main #3) that need to be sealed to prevent oil leakage at the tall exterior castle nut.
Methods of sealing can be:
1) Epoxy (Loctite 1360700)
2) A flexible sealant (Permatex “Black Gasket Maker” 27037) or (Permatex “The
Right Stuff” 29208).
3) A 10 mm ID x 1.5 mm width O-ring that fits into a 0.079-inch-wide x 0.031
inch deep groove in the 0.500 inch diameter of the stud shank can be machined
into the stud. The groove should be located at 2.17 inches below the 1/2-20
UNF threaded end. The McMaster Carr part number for the O-ring is
1295N162. This was suggested by Brian Weber. If you choose to use this
method of sealing, push the stud up and install the O-Ring where the castle nut
is and then pull the stud down. This method lessens the possibility of damaging
the O-Ring on assembly. John Lampl at
www.burtzblock.com has the studs
with the O-Ring groove in stock and available for a small cost.
4) A packing (cotton string and Permatex #2, 80011). If the decision to use a
packing is made, then the Permatex impregnated string must be wound around the
7/16-inch shank and firmly packed with a curved tool that is .030 inch thick.
5) An O-ring between the 7/16-inch diameter stud and the 1/2-inch bore in the
cylinder block. Lawrie in Australia reported that a 1.5 mm cross-section x 10 mm
ID (0.059 x 0.393 inch) Viton O-ring worked for him (McMaster Carr 1295N162).
A 1 mm cross-section x 10.5 mm ID (0.039 x 0.413 inch) Viton O-ring (McMaster
Carr 1295N129) should also work and be a little easier to install. If the choice is
made to use an O-ring, the O-ring and mating parts need to be lubricated with motor
oil to prevent installation damage.
A tool made from a piece of tubing that is 0.500-inch OD and 0.444-inch ID
(McMaster Carr 89955K471) can be used to help with packings or O-ring
installation.