460 Cam bolt

Why so many standards? What's the prevailing logic?

New Pro Comp Forged Cam - 3/8 UNC
AlkyDigger  Hex drive button - 7/16 UNF
Nicson/Magnaflow cam drive - 7/16 UNC

Clarity anyone.  My eyes are starting to cross again!  

Steve

What’s a pro comp forged cam?

dfree383 wrote:What’s a pro comp forged cam?

COMP Cams 34-850-9 Xtreme Marine Solid Roller Camshaft.
Steve

quarterflash wrote:Why so many standards? What's the prevailing logic?

New Pro Comp Forged Cam - 3/8 UNC
AlkyDigger  Hex drive button - 7/16 UNF
Nicson/Magnaflow cam drive - 7/16 UNC

Clarity anyone.  My eyes are starting to cross again!  

Steve

It all pretty much has to do with whatever valve spring force is necessary with THAT camshaft.
A 3/8 bolt on a roller cam is a no-no in my opinion.

quarterflash wrote:Why so many standards? What's the prevailing logic?

New Pro Comp Forged Cam - 3/8 UNC
AlkyDigger  Hex drive button - 7/16 UNF
Nicson/Magnaflow cam drive - 7/16 UNC

Clarity anyone.  My eyes are starting to cross again!  

Steve

A bit of history on the subject:

The original 385 Series engines all came with a 3/8-16 threaded cam bolt, and so this is what the aftermarket roller cams all originally came with. Back in the 1980s racer Van Heskett started putting his solid roller cams in his milling machine and boring/tapping all his cam bolt holes to 7/16-20 thread for his 460-powered race cars. Shortly thereafter while he was setting up the first ever solid billet Boss 429 heads for Chuck Seyler, Seyler mentioned to Heskett that he had started instructing Crane Cams to make his cams with a 7/16-20 threaded bolt hole. So it seems both Heskett and Seyler each came up with the 7/16 460 cam bolt at about the same time.  After a few requests to Crane from Seyler for this mod, Crane started offering the big bolt as an option in their roller cams.

Comp street roller XR-292-R is 7/16 UNF.

Double dowel pins and a 7/16 bolt with a performance intended camshaft should just be a standard thing. The damage that can result from a failure is way too severe in my $.02 opinion.