cam button for roller cam

[1987]

Hello, I ordered a comp roller cam and it came with a comp cams cam button that is to be shimmed to set up. Is this the only way to go with the roller cam? also, if so, does anyone have instructions on how to set it up or how much movement there should be?

 

[Just a Six??]

Some rollers use shims & some use a stock style button. Don't they include instructions on how to shim it?

 

[1987]

reply

i dont see any instructions. why not use a cam button with a spring?

 

[LOT]

billet or cast cam??

depends on which one you have as to how to set it up. I shoot for 005-.010 end play for either one .

 

[buickboy]

Comp Roller cam

Instructions that came with my comp roller kit say that the cam thrust spec is .005-.010 using the shims that come with the cam button. There is absolutely no way to get it exact as the front cover is installed when checking thrust. i did it by using a screwdriver and moving the cam down through the valley drain holes and if you see very slight movement then you are good. You must test fit the fron cover and then recheck the thrust several times unless you get lucky first time. If someone knows a fool proof way of verifying thrust with this setup, i am all ears. i asked the same question before i installed mine and no one chimed in with a fool proof accurate procedure.

Mitch

 

[1987]

thanks, i was wondering how to check the thrust with the cover on...

 

[Rodney87GN]

Instructions that came with my comp roller kit say that the cam thrust spec is .005-.010 using the shims that come with the cam button. There is absolutely no way to get it exact as the front cover is installed when checking thrust. i did it by using a screwdriver and moving the cam down through the valley drain holes and if you see very slight movement then you are good. You must test fit the fron cover and then recheck the thrust several times unless you get lucky first time. If someone knows a fool proof way of verifying thrust with this setup, i am all ears. i asked the same question before i installed mine and no one chimed in with a fool proof accurate procedure.

Mitch

The way I did it...and easiest way I know...is to use a dial indicator with a "see-saw" attachment. It's kinda hard to explain without actually seeing it in person. But basically set it up where one end of the see saw touches a cam lobe thru one of the valley drain holes. The other end of the see saw touches the dial indicator stem. When you move the cam fore and aft the see saw transfers the movement to the dial indicator. If set up all correctly it's just as accurate as reading it from the rear of the block.

I borrowed a Starrett dial indicator set at work. I can take a pic of it tomorrow if you want to see what I'm talking about.

 

[buickboy]

Thanks for that new attachment idea. Where would someone get that indicator attachment?

 

[Rodney87GN]

OK here's those pics as promised...


The "see saw" attachment-

Attached to dial indicator, one end contacting the indicator's stem-

A view of it all set up...make sure everything is straight and tight so you get consistent and repeatable readings. A magnetic base would make this A LOT easier! This particular kit uses a small C clamp which makes it a bit tricky to get it setup straight.

And the other end of the attachment at the front of the cam lobe at its high point...make sure it's not touching anywhere on the valley drain hole-

Starrett, Mituyomo and others carry this attachment. This set is from Brown and Sharpe, not Starrett as previously mentioned.

Hope that helps.

 

[DR BOOST]

plastiguage on the cam button?

you can also just put the dial indicator through the oil drain straight to the timing gear.

 

[Jeff Rand]

I install the cam, cam button and the timing chain gasket and cover. Then I push the cam forward with a screw driver (through the drain back holes) as far as it will go. I then carefully remove the cover and place a zeroed out dial gauge on the front of the cam ( in my case the indicator base is magnetic, so I attach it to the front of the block) and push it back to see the free play.
Jeff