Well, I'm glad I've done some reading on this cam swap and not just thrown the parts in and go.....

Have a look at the measurements in the pictures....

This picture is with the stock retainers and keepers.....


This picture is with CC 4705-16 seats, CC 795-16 10* retainers, and 614-16 10* +50 locks...


Now, according the reading I've done, these beehive springs(PAC-1518) need to be installed at 1.75 - 1.78. According to the pictures....I'm off the mark.....what causes this???? Is it valve/valve seat wear??? Is this wear too much to shim safely? Do I need to pull the head and look at the valves?

I'm not panicking, but I certainly need some guidance...

 

Well, I've been sitting here fuming and trying to figure out why the spring height is around 1/8" off. So...I mic'd the total length of the barrel mic....



Here is the recess depth....


You know, this really pisses me off. Shouldn't the 1.600 measurement be from the bottom of the recess to the bottom of the mic??? Not from the top to the bottom???? Seems a bit misleading to me.....

However, if I subtract the recess depth.....0.149 from the measurements in the top pictures...

Stock = 1.902 - 0.149 = 1.753"
Beehive hardware = 1.8735 - 0.149 = 1.7245"

I think I can tighten the mic a couple more thousands.....on both measurements....I just snugged the barrel mic.

Does anyone else's barrel mic do this??? Or does the reading "start" in the recess. The barrel mic I have is a Proform(maybe that's my problem???).

 

I believe my spring mic goes from top to bottom (like yours actually seems to do from the pics). You will have to factor out the recess if that is where the retainer sits.

 

You have the micrometer used for Dual (non beehive springs) Two ways to go about this get a spacer built for the existing mircometer or buy the new beehive mircometer comp has. That is most likely why your readings are off. If not you need to revaluate your shims to get the correct install height.

P.S. check every single valve when measuring install height no just 1 exhaust and intake valve. Believe it or not tolerances can be slightly different.

 

That's a standard deal with that style micrometer. All small diameter retainers require the extra step of factoring in the depth of the step. It's cheaper than buying a separate mic when you're setting up a variety of heads with different retainers. The retainers off my 1.625" springs wouldn't work at all on a mike with a smaller O.D.

 

I don't have beehives, so I did not need the special mic. I'm not the one with the problem.

 

I used the same proform mic. when I was setting up my pac1218s.
I just placed the mic. on a flat surface, adjusted the dial caliper to 1.75" and put it where the beehive retainer sits and the stick from the caliper down in the hole and adjusted the micrometer untill the stick touched the "floor", too see what numbers on the proform mic. I was looking for.
I think I ended up with 1.915" or something on the proform mic. for 1.75" install height.

 

That's a good way to do it.

Obviously, this is my first time using a barrel mic. I was caught off guard with the way the height is measured. I expected the measurement to be from the bottom of the mic to the top of the recess.

How snug should I get the mic against the retainers? It's looking like I may be under the 1.75 install height(1.72 or something close to this...will better check today...I was in a hurry last night....just wanted to try out the mic...you know how it is with a new tool ). Is it better to be a little tight on the spring? Just thinking about it.....the tighter the spring, the less travel you have...so I cut down on the lift ability of the spring...however if I don't push to the limits of the springs...I should be fine. Right? With the springs ability to go 0.650 at 1.80, I should be fine running 0.536 and 0.544 at 1.72....right?

 

Ugh....just did some math....I think I need the 1.75 to 1.8....

 

The PAC1518 is good for 0.650 @ 1.8 right?

So doing the ratio thing.....looking for max lift at 1.72

.650/x = 1.8/1.72
x1.8 = 1.118
x1.8/1.8 = 1.118/1.8
x = 0.621

Well, nevermind...looks like it may be fine.

 

Looking at the specs of the spring, the max lift you could have @ 1.72" height would be .570 so you should be fine

But you should check install height at every valve!