Cam Pin?

FAIRMONT MIKE said:

Should a person double pin the frpp solid roller cam?
Specs are [email protected]" with .647" lift if memory is correct,
200-210 on the seat with 490-500pounds open.
All thoughts and ideas welcome.

P.S. I already made sure the cam does not protrude beyond the gear, and have a gr8 7/16 fine thread cam bolt with a .250" thick...washer

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I don't think that your particular application and components dictate the necessity of the double-pinning. It wouldn't hurt anything, but I feel it's an unecessary expense in your particular case.

Like many things that trickle down from higher performance racing conditions, there is a lot of overkill going on in milder engine builds. The camshaft dowel pin does more for locating the cam gear duraing assembly than it does for maintaining cam phase. The clamping force of the cam bolt does more for maintaining cam phase than does the pin. The pins usually shear when the cam bolt is not providing the necessary clamping force to hold the cam gear in position. Often, the lack of clamping force is just enough to shear the pin and leave little (if any) indication that the clamp load was inadequate.

Double-pinning may be viewed as a modification to the single pin's originally intended purpose of locating, and that adding a second pin is done in an effort to allow the pins to carry some of that load but split the load between two pins. It certainly is a wise fail-safe in a super powerful engine, but not a garantee that your cam bolt is up to its job and/or the installation of the parts was executed in an ideal fashion.

We have done engines with larger spring pressures than yours (seat & open pressures) and stayed with the standard single cam pin with 7/16 bolt. What's very important is the prepration and inspection prior to assembly: full inspection of the mating parts; cleanliness of the parts; perfect machining and no galling of the mating parts; proper seating and fitment; quality fastener hardware; good bolt torque and correct application of thread locking agent.

So I feel it won't hurt to do it, just not necessary and an added expense.

Paul

gafred99 said:

I have only seen the 7/16 bolt on Crane roller cam, other brands state not avail.

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Long before any cam manufacturer offered a 7/16" cam bolt for the Ford, my engine building partner/forum member, Van, was taking newly purchased cams and setting them up in a mill and boring/tapping the end of the camshafts to 7/16-20 thread. One day he was talking on the phone to Chuck Seyler (first ever Ford in the 5's QM) and discussing the 7/16" cam bolt modification, and Seyler revealed to Van that he was ordering cams from Crane and giving them special instructions to bore & tap for a 7/16-20 cam bolt. So these guys were the first guys ever to do it, as far as I know. Shortly thereafter, probably in reply to Seyler's special order 7/16 thead, Crane began offering their cams with 7/16-20 bolt threads as a shelf item.

A recent roller cam I used was a CompCams shelf item with a 3/8-16 cam bolt thread, but it was special ordered with a 7/16-20 cam bolt thread, so probably anyone can do it for you upon request, or at least CompCams can do it for you.

Paul