Cam gear question

HDTony · Feb 23, 2012

It's probably a simple question, but I want to make sure. Never dealt with timing gears before. With my cam gear the cam is not "flush" with the face of the gear? Is this an issue. People have told me its no problem, but I'm Leary about it. Also how important is it that the dowel rod protrudes the front of the gear to engage the fuel pump eccentric. I would think its important, but again I have this guy telling me it's not a problem.

2+2GT · Feb 23, 2012

Not sure wat you mean by 'flush'. There should be no in/out play with the gear installed. It is absolutely critical that the pin protrude through the eccentric.

HDTony · Feb 23, 2012

look at the pic I attached. particularly the center of the cam gear. the cam is recessed in the hole, I was thinking it should be flush or even with the front of the cam gear. good call on the dowel pin, looks like I'll have to make one custom

PoppyMod · Feb 23, 2012

Hi,
I too, am not sure what you mean, as well. The cam timing chain gear should fit flush to the face of the cam and within the machined recesses of the gear. The install of the cam has what's called a "thrust value" and has to be measured with a dial gauge to get it get it correct. The specs I used had parameters of .001-.007. Mine dressed out at .004. I'll describe the "thrust" as the fore and aft movement of the cam installed with it's retention plate torqued in place and the cam gear torqued in-place relative to the surface of the plate. The machined boss/face of the cam gear can be reduced if too tight (<.001) or thrust washers added if too > (exceeding .007).
Hope this helps and is not too confusing..

ihadagt500 · Feb 26, 2012

Looking at the picture, the install appears normal. The nose of the cam is not supposed to stick out or even be flush with the face of the sprocket. Put the bolt and thick washer on and tighten it up, as PoppyMod said, you should have .001 to .007 end play between the cam retainer plate (that is bolted to the block) and the back side of the sprocket. If you can't turn the cam, then it is too tight. As far as the dowel pin, it depends on whether you are using a fuel pump eccentric or not. Now if you are not using one, reinstall the counter weight slinger, its tab goes into the hole where the dowel is short. Since this is a smooth face sprocket, you can't use a 2 piece fuel pump eccentric. If you are using a fuel pump eccentric, it has to be an early 1 piece, so then yes, you need a longer pin to go into the hole in the eccentric. Or you can do like the police 351W's did. On this engine they used a 2 piece eccentric, but unlike most 2 piece units with a tab on the back, they were drilled for the dowel to come thru, only they still used a short dowel in the cam. Ford then installed another shorter dowel into the sprocket, butting up against the one in the cam, and that stuck out out just far enough to drive the eccentric. The large thick washer kept it in place, and yes it sounds hokey, but worked just fine.
One last word, if you decide to make a dowel pin, make sure it is a hardened piece of steel, I've seen guys try to make them from grade 8 bolts, only to have them break.

woodsnake · Feb 26, 2012

Also, you will have to rotate the gear so the "dot" on the cam gear matches the "dot" on the crank gear. The set needs to be installed "dot to dot".

HDTony · Feb 29, 2012

ihadagt500 said:
Looking at the picture, the install appears normal. The nose of the cam is not supposed to stick out or even be flush with the face of the sprocket. Put the bolt and thick washer on and tighten it up, as PoppyMod said, you should have .001 to .007 end play between the cam retainer plate (that is bolted to the block) and the back side of the sprocket. If you can't turn the cam, then it is too tight. As far as the dowel pin, it depends on whether you are using a fuel pump eccentric or not. Now if you are not using one, reinstall the counter weight slinger, its tab goes into the hole where the dowel is short. Since this is a smooth face sprocket, you can't use a 2 piece fuel pump eccentric. If you are using a fuel pump eccentric, it has to be an early 1 piece, so then yes, you need a longer pin to go into the hole in the eccentric. Or you can do like the police 351W's did. On this engine they used a 2 piece eccentric, but unlike most 2 piece units with a tab on the back, they were drilled for the dowel to come thru, only they still used a short dowel in the cam. Ford then installed another shorter dowel into the sprocket, butting up against the one in the cam, and that stuck out out just far enough to drive the eccentric. The large thick washer kept it in place, and yes it sounds hokey, but worked just fine.
One last word, if you decide to make a dowel pin, make sure it is a hardened piece of steel, I've seen guys try to make them from grade 8 bolts, only to have them break.

Thank you!! very informative post and you confirmed all my thoughts. it just so happened I also had a 2 piece with a tab in my stock pile of parts so I ended up using that. worked perfectly! thing is on and setup, water pump is on, now onto the manifold and carb.

And don't worry wood snake, that was just to take a pic, I made sure the timing was spot on

Cam gear question

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