Cam gear question...

[bugnut68]

I've got my bottom end mocked up for my 2017 build... but have yet another (imagine that!)  question regarding the cam gear.  My cam gear is a VW gear set up for bolts on my Engle 125 cam.  There doesn't seem to be much backlash, if any, when indexed with the timing gear on the crank.  Looking at the gear for a pitch number, all I find (other than the dot for aligning the gear with the crank gear's marks) is the number '5' but no plus or minus.

Mind you, the gear slightly rises out of the cam bearing saddles on the gear end when the crank is turned in one case half.  When the case halves are torqued together, there is no binding whatsoever. 

My question is how do I determine what gear I need, as I'm to understand the gear should have some slight backlash against the crank gear.  What do guys running the helical (stock style) aluminum gears do, just let it wear itself in?

[Jim Ratto]

you might want to pick up Berg's book of instructions/technical articles. A lot of these issues are clearly explained in both of those books.

No, don't let a "tight cam gear" wear in. You'll have trouble on your hands. My good friend Kyle got scammed out of a pricey motor he had built for him in 1996. It all started with a cam gear that was eaten by the steel stock crank gear. This motor had single HD springs, so before you point your finger @ spring pressure.....
I use green Plastigage to check lash.

[bugnut68]

I've got the Berg tech articles and instructions... I'm just at a bit of a loss as I don't know what pitch my gear is.  Did the gears have a "+" or "-" sign with the pitch number on the face of the gear?  Mine just seems to have a number 5, but no plus or minus sign.

I've never used plastigage before... how is it used, do you have a link with a pictorial instructional breakdown?

[bugnut68]

As an update, I checked again last night... as per the Berg book, the crank was turned counter-clockwise and the cam did not lift out of the cam bearing saddles.  At the risk of being too "loose," I followed the directions to hold the cam down at the flywheel end and check for backlash.  There was none, which, according to the book, indicates that it should be fine, or at least this is my understanding.

[nicolas]

if you did it ike you say and the cam didn't jump and no backlash was felt, it is OK

[bugnut68]

if you did it ike you say and the cam didn't jump and no backlash was felt, it is OK

What I thought was jumping out of the saddle before I believe was operator error/cam not fully seated, as it has not done it since.  I've gone through several times.

[Jim Ratto]

you need to make sure end thrust is set before you check gear lash,

[bugnut68]

you need to make sure end thrust is set before you check gear lash,

Checked it, the spec is .002 to .004, if I remember right?  Mine measured in right at .004.  Is it preferable to be more in the middle for cam end play?  I happened to have a complete set of cam bearings left over from a previous build, but if .004 is on the loose side, I will get a new set and reapproach it.