Douple pinning cam-engine already together and running

On an engine already put together how would one suggest adding a second pin to the cam? Drill and use some type of reamer and use a pin with lock-tite? or drill and tap it with a 1/4 20 thread and add another bolt?

What determines when this is needed? Spring pressure on heads? RPM?

Needed on a 800-850 HP solid roller lift deal?

I appreciate any feedback

Thanks

No can do. You'll get metal shavings in the engine and in the oil pan. Pull the cam, take it and the timing gear to a machine shop and have them do it.

Charlie

Like Charlie says....
The pin has a different reamer size for the cam, so the pin is pressed.
Clearance size reamer in the gear, so it slides off.
Most shops perform the operation with a fixture...in a mill so everything is straight and square.
Keith

Shoulda done it from tbe git go, imo the 7/16 - 20 bolt is more important.

I do both on all sr cams

away wrote:On an engine already put together how would one suggest adding a second pin to the cam?  Drill and use some type of reamer and use a pin with lock-tite?  or drill and tap it with a 1/4 20 thread and add another bolt?

What determines when this is needed?  Spring pressure on heads?  RPM?

Needed on a 800-850 HP solid roller lift deal?

I appreciate any feedback

Thanks

Valve spring pressures?

Thanks for all the responses.

I have never had an issue with this bc I use a good rod bolt and torque this bolt to the bolt specs.

I guess I am wondering why this is needed or suggested.

Thats why i asked about valve spring pressure on the heads. Is the second pin recommended when the valve spring pressure gets say over 220lbs on the seat or higher?

just wondering I guess.

away wrote:Thanks for all the responses.  

I have never had an issue with this bc I use a good rod bolt and torque this bolt to the bolt specs.

I guess I am wondering why this is needed or suggested.

Thats why i asked about valve spring pressure on the heads.  Is the second pin recommended when the valve spring pressure gets say over 220lbs on the seat or higher?

just wondering I guess.

700/750 pounds force OPEN is about the threshold. A good thick hardened washer along with a high torque alloy 7/16" bolt is usually alright up to that point.

I used a Danny Bee pin - which is supposed to be better than the pins supplied with the cam I was delivered.
I also used a modified SBC harmonic balancer bolt and thick washer.

Hopefully the combination will work out.

rmcomprandy wrote:

away wrote:Thanks for all the responses.  

I have never had an issue with this bc I use a good rod bolt and torque this bolt to the bolt specs.

I guess I am wondering why this is needed or suggested.

Thats why i asked about valve spring pressure on the heads.  Is the second pin recommended when the valve spring pressure gets say over 220lbs on the seat or higher?

just wondering I guess.

700/750 pounds force OPEN is about the threshold.  A good thick hardened washer along with a high torque alloy 7/16" bolt is usually alright up to that point.

Randy,very good information thanks for sharing.

It's also very important to make sure everything goes together right and everything is flat against the part and the snout is not protruding out beyond the gear, also make sure the bolt does not bottom out then being installed.