[Supras] Hopefully useful ARP head stud information
Don R
tsupra at frii.com
Sun Jul 29 21:30:38 CDT 2007
not sure what is up with your head but every engine i've built i used a craftsman socket,
deep well, that wasn't turned down on the arp studs.
berniek at technicaldevelop.com wrote:
> During installation of a Cometic HG, I learned a few things which may be
> of assistance to those who have not dealt with ARP head studs before:
>
> 1. Always thread the studs into the block with the 3/16 hex depression
> in the top. That way they can be removed if needed.
>
> 2. The socket to fit the nuts requires machining unless there exists a
> special socket I could not find. I got a Sears 12 point 14 mm 1/2"
> drive socket, number 44444, the heaviest they had. To clear the bucket
> housings, camshafts and center valley wall, the socket had to be
> machined as follows:
>
> a. For the first .740" of the length starting from the nut end, reduce
> the diameter to .765". That involves removal of about .015" to.020"
> from the business end of the socket. It will be necessary to use a
> carbide bit in the lathe. The socket is of high quality, made from
> tough steel. The surface finish will not be spectacular, but such is
> the price of machining hard steel without more involved finishing
> techniques.
>
> b. Then reduce the diameter towards the drive end to .735" for a
> further length of 1.650". So the total machined length from the nut end
> will be 1.650' + .740" = 2.390". That reduced diameter is to clear the
> camshafts and center valley wall. There is plenty of meat in the socket
> wall once above the 12 point end, so no real weakness will exist. Do
> not go further back in machining or you will cut through to the corners
> of the 1/2" drive recess.
>
> 3. Set the camshafts both so the TDC marks are upwards. All nuts will
> then be accessible past camshaft bumps, hex sections, etc.
>
> 4. The washers MUST be installed on the head surface before the studs
> are installed. They will not fit the studs afterwards due to the bucket
> housing wall thickness.
>
> 5. Using the moly lube supplied by ARP, torquing to 80 lb-ft. was no
> problem, done in four stages. The socket held up perfectly.
>
> 6. If you have had the head and rear timing cover decked (necessary
> with any MHG, the ends of the gasket pieces will stick up above the head
> surface. They must be cut off flush since the gasket covers that junction.
>
> 7. It may be possible to carry the nut end diameter to .765" before
> carrying it back to .740" diameter section However, that will weaken
> the socket at its must vulnerable point, the nut end where the wall is
> thinnest.
>
> Hope this of some use.
>
> BernieK
>
>
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