Greetings . . .
Finally I feel like I am spending more time building up then tearing down . . . headed in the right direction!
It's been quite cold here in Ohio this winter so I have moved to the basement. This past weekend I finished up the head assembly:
The internal surfaces are coated with Glyptal Red to keep the oil clean and draining back freely.
The same coating was used as the primer for the external surfaces. The finish coat is from the Filling Station and is considered the correct shade of factory blue-gray (a subject of much debate).
The spring package was originally planned to be Buick straight eight. I purchased a set of aftermarket springs from ebay quite a while ago. Allied was a NAPA supplier out of Cincinnati:
But the plans changed in ’07 when I snagged some McGurk go fast goodies:
I got a good price - as the package was incomplete. It was claimed NOS but the shims included showed obvious signs of wear:
The box inventory called for 36 shims – of which I have 31. The shims are in two thicknesses’ - .0225” and .025”. The thinner ones are trademarked HOUSER Bluffton Indiana:
I puzzled over the collection and began sorting them by thickness.
It wasn’t until I stacked them together (and measured various stacks with my calipers) that it became apparent I had the makings for an .050” and an .070” set of shims:
I hadn’t given the shims much thought until I installed the springs on the head without them.
With the McGurk parts in hand I decided that the spring package for the build would be Buick outer and McGurk inner (a preferred setup in Bill Fisher’s book):
Absent the shims the installed height (with stock spring aligners on the bottom) was 1.85” on the intakes and 1.91” on the exhausts.
Stock installed height specification is 1.84375”. McGurk recommends 1.78125” (which California Bill suggested is for “really wild cams”).
By shimming the exhaust springs .070” the installed height is reduced to 1.84”. Shimming the intakes by .050” the installed height is reduced to 1.80”.
California Bill’s book warns about coil bind when using the McGurk specification.
With the hold downs from the McGurk package:
I am not anywhere near the 1/16” to 1/32” minimum clearance between coils on the outers. The McGurk pieces definitely compress the inner spring more.
These are closer to bind when measured in a bench vise.
I will need to watch the inners closely after installing, lashing and lifting with the actual rockers (which typically yields less lift then arithmetic from the cam card lift spec minus lash).
I have a dial indicator so there won’t be any guess work here.
regards,
stock49
