hugoct wrote:Panic,
There is a 1952 bulletin titled "Instructions for installing "Flat Tappet Kit" on model "K" motor" it predates the bulletin you posted from 1953.
The layout of the page is identical but the diagram shows an engine with the WR style valve train components. The following parts differ 18220-30 valve spring collar, 18228-30 valve spring collar key, 18515-52R Tappet assembly, 18566-40 tappet adjusting screw, 18605-52R front tappet guide, 18605-52R rear tappet guide, 25520-52R front exhaust cam, 25521-52R rear intake cam, 25522-52R rear exhaust cam, 25525-52R front intake cam. The timing check specs are the same which would indicate that the cam timing was the same. This may be the smoking gun regarding the legend of the 1952 KRs coming with WR style cams and tappets.
Regards
Milburn
The cam discussion here has brought a new question to mind, specifically, a question relating to cam part numbers. I am familiar with cam set part numbers due to the various on-line sites and manuals that provide such information (Patrick’s KR/XLRTT, Panic's Victory Library, factory KR/XLR manuals, etc), and in the majority of cases see the cam sets listed as 25499-XXR part numbers, where XX is the year of the part, and the earliest set being 25499-53R. However in the quoted text above the cam part numbers end in -52R, which is the earliest -R cam part# I know of. Was there a -52R cam set for K Models, and if so, might anybody have the factory specifications for the -52R flat tappet cams?
Circling back to the original subject of what cams, labeled KR2 and KR3,might be in Jerry’s friend’s engine, it would be interesting to know the lobe height and base circle dia of these cams so we know what lift they are. From the -53R KR cams going forward all the KR cams had at least 0.395” lift. Makes me wonder what the lift of the -52R cams was. I’ve heard it suggested around the camp fire that the KK/KHK cam was the same as the early KR cams, yet the early KR cam, 25499-53R, is listed as having 0.395” lift and KK/KHK cams do not have this high a lift. Did early KRs actually use the KHK cam?
More questions than answers, but hopefully we can make a dent in it.