I'm having 'issues' !

I need too - and can not - find a Cam Button that will properly fit my Flat Tappet Camshaft. The diameter of the Cam Sprocket "hole" appears to be different on Flat Tappet Cams than it is on roller cams; I do not have a roller cam floating around to verify this,... but all the Cam Buttons I find are of the wrong outer diameter.

Has ANYONE EVER installed a Cam Button on a Flat Tappet Camshaft ??? If so,... could you tell me where to find / purchase one ??

** Before anyone posts: Flat Tappet + Gear Drive. ( You don't have to waste your time explaining why a roller cam needs a button and a flat tappet cam doesn't. )

 

I put one on a retrofit roller cam but never on a flat tappet.

 

Opps i elaborated

 

https://www.speedwaymotors.com/SBC-R...ors%20Products

or comp 200 works well. There are two sbc cam sprocket patterns roller and flat tappet. Who produces the gear drive ? Wonder if worth emailing the manufacturer.

 

Are you able to fabricate a button? I have made them out of aluminum and fiberglass rod.
You are going to have to set the clearance to the timing cover. .008" IIRC

 

Both the Speedway set and the Comp 200 are for Roller Cams:

The Gear Drive is a "quiet" DynaDrive from DynoGear and it appears that any flat tappet gear drive DOES come with a cam button that fits their Cam Gear; I just can't find a 'stand-alone' cam button to buy anywhere ! DynaGear got acquired by Cloyes in 2003; but I can't find a similar Cloyes gear right now ( Proform SBC Drive Gear looks right,... but says it's a "noisy" set). Funny thing is that my DynaDrive kit appears to be EXACTLY the same as Edelbrock 7890. ( same 78400 number on the dog bones, same cam gear and everything. )

https://www.summitracing.com/parts/edl-7890


.08 play would be perfect,.. it's getting there that's a problem right now. I can't find a Cam button that's .075 in diameter. ( Can't use an Aluminum thrust because it will cause 'galling' when it touched the Aluminum cover...... Nylon Preferred but Steel if I have too. ) I'd like to find a useable Cam Button off the shelf,.. but might have to resort to something *custom* if I can't find anything soon ! !

This Cam Button came with the Drive Gear kit - I need one that's a little longer.


The silver Cam Button above the caliper is a "virgin" duplicate cam button from a second DynaGear Gear Drive kit. You can compare it to the black AllStar Cam Button above it ( that one is made for roller camshaft-in-flat tappet blocks )

 

The reason you can't find one "for flat-tappet", is that no one uses them for that. Generally they're unnecessary because the lifters push the cam rearwards.

The cam doesn't determine the size you need, anyway. The timing set sprocket does. The front of the cam itself is flat, maybe with a small hole, maybe ¼" dia at most. The button doesn't go down into it regardless. A "retrofit" roller uses the same timing sprocket as a flat-tappet cam anyway, and that's what you'd typically need a button for to begin with, which is why they're specified as being "for roller cams". A factory roller, whose cam sprocket has a much smaller center hole, doesn't generally need one, because it has a retainer plate. Only a retrofit roller needs one, except if you're trying to put a factory-roller cam into a retrofit situation without a retainer plate (i.e. just a spacer). But if you wanted to use one for whatever reason, one made for retrofit roller would fit a flat-tappet setup since they're the same.

Sounds to me more like your gear drive (with which I'm not familiar) has a hole in its cam sprocket that's a different size from one for a chain, and that's what you're having trouble fitting to; NOT the cam itself.

However all that may be, it's not real critical how it fits into the sprocket. As long as it goes in, and is the right height, then it'll be fine. Take the plastic one, chuck it up in your drill press, and carve a little off of it with a utility knife or something. Or maybe some real coarse sandpaper.