Posted By: gss
Comp Cams cam button - 03/03/15 05:11 AM
I can't find any information on how they are installed. What holds them on?
Comp Cams cam button
Posted By: Cab_Burge
Re: Comp Cams cam button - 03/03/15 05:21 AM
It depends on which motor and which cam gear, IE single bolt or three bolts on BB, Hemi or if your working on a L.A SB motor 
OOPS, not needed on LA motors with the stock cam retaining plates 
OOPS, not needed on LA motors with the stock cam retaining plates
Posted By: Stanton
Re: Comp Cams cam button - 03/03/15 06:03 AM
The timing cover holds them in !!!
Posted By: gss
Re: Comp Cams cam button - 03/03/15 06:07 AM
It's a 3 bolt Comp Cams XR280R
Posted By: gss
Re: Comp Cams cam button - 04/01/15 04:44 AM
Well this is starting to get a little aggravating. The cam/lifter/timing gear set I got from Comp cams didn't include the required cam button or the 3 cam bolts. So I get the recommended button from CC and the smallest head cam bolts I can find from ARP and the button still doesn't fit without hitting the bolt heads. Am I expected to put this button in a lathe and turn in down? There has got to be a better solution. What do you guys do with these?
Posted By: Cuda367
Re: Comp Cams cam button - 04/01/15 05:30 AM
Allen headed bolts worked just fine. Just finished one this week. The real problem is clearance. I like .004 to.006 cam end play. I install the cam with button and gear in place and nothing else. Then I bolt on water pump housing with gaskets in place using a feeler gauge I find the clearance between back of housing and button. Measure thickness of timing cover then find a washer that when tack welded to cover will give the clearance I want. Aluminum cover will not flex but steel cover will flex a lot.
Posted By: Stanton
Re: Comp Cams cam button - 04/01/15 03:53 PM
The only bolts I've found that a) have a narrow enough head for a button to fit and b) fit under the cover without hitting are called "low head socket head cap screws". These look like an allen head cap screw but are about half the height. You won't find these at Lowes or Home Depot - you'll need to go to a place that specializes in nuts and bolts.
Any time I tried, standard allen head bolts didn't fit under the cover.
Any time I tried, standard allen head bolts didn't fit under the cover.
Posted By: Stanton
Re: Comp Cams cam button - 04/01/15 03:59 PM
The topic was well covered a while back. Do a search on "cam walk"
Posted By: gss
Re: Comp Cams cam button - 04/01/15 08:46 PM
There is some good info in that thread, thanks
I tried allen head bolts but they only fit if I leave out the washers. I will check with Fastenal for low allen head bolts.
I tried allen head bolts but they only fit if I leave out the washers. I will check with Fastenal for low allen head bolts.
Posted By: AndyF
Re: Comp Cams cam button - 04/01/15 09:27 PM
Quote:
Well this is starting to get a little aggravating. The cam/lifter/timing gear set I got from Comp cams didn't include the required cam button or the 3 cam bolts. So I get the recommended button from CC and the smallest head cam bolts I can find from ARP and the button still doesn't fit without hitting the bolt heads. Am I expected to put this button in a lathe and turn in down? There has got to be a better solution. What do you guys do with these?
It is all application specific. I think most engine builder come up with a combination that works for them. I used to use Hex-a-just timing sets with my own cam button and ARP bolts. But as soon as you switch brands you run into issues. Everyone builds their stuff to slightly different dimensions. Typical hot rodding problem.
Posted By: Stanton
Re: Comp Cams cam button - 04/01/15 10:10 PM
Quote:
they only fit if I leave out the washers
Ditch the washers.
Posted By: gss
Re: Comp Cams cam button - 04/02/15 06:07 AM
After taking a closer look, even after removing the washers, the button still hits the ARP bolts. Allen head bolts are even larger in diameter than the ARP bolts. If someone here has installed a Comp Cams nylon button, I would like know how you cleared the bolts.
Posted By: RAMM
Re: Comp Cams cam button - 04/02/15 01:05 PM
Just went through this last week. Had to turn down the button in my lathe. PITA for an issue that should have been solved 20+ years ago. J.Rob
Posted By: MoParFish
Re: Comp Cams cam button - 04/02/15 03:49 PM
Quote:I went through the same thing on the first one I did. I turned the button around and machined(actually did it with drill and bench grinder when I didn't have access to a lathe) the big end to fit the timing gear and faced it so the large end step goes flush with the face of gear. Then the bolts and washers capture the button so it can't fall out. Now, I keep a 1" diameter piece of Delrin acetyl plastic around and make them as needed. Done a couple since. I machine the cover side of button small enough so there is no problem with bolt or washer interference. Like said, I did the first one with a drill and grinder. Not too sterile but that motor has been thrashed on with a ton of nitrous and still together sitting on the floor ready for it's next venture. Sorry, don't have a pic.
After taking a closer look, even after removing the washers, the button still hits the ARP bolts. Allen head bolts are even larger in diameter than the ARP bolts. If someone here has installed a Comp Cams nylon button, I would like know how you cleared the bolts.
P.S. As memory serves on that first one, the small end was too big to chuck in drill so I drilled a 1/4 inch hole through the center of the button as straight as possible, then pressed the appropriate size drill bit in to serve as a mandrel and worked slow. Again, not ideal but did what I did. For the others, I used a lathe, much nicer
Posted By: Stanton
Re: Comp Cams cam button - 04/02/15 03:51 PM
It doesn't have to be pretty ... hit it with a grinder or whatever. Nylon will not wear unless the contact surface (the timing cover) is rough so it doesn't matter if the end is round. You're likely going to have to grind the end to get the right clearance anyway.
Posted By: 68 HEMI GTS
Re: Comp Cams cam button - 04/02/15 04:41 PM
just take a die grinder and a burr and clearance the 3 spots where it hits the bolts. not a big deal.
Posted By: gss
Re: Comp Cams cam button - 04/06/15 03:13 AM
Quote:
just take a die grinder and a burr and clearance the 3 spots where it hits the bolts. not a big deal.
That is what I ended up doing. End play is .012". If I leave the gasket out, then I measure .009". I am surprised it is that loose. I would think they would make them oversize so they can be cut down for the desired end play. I'd rather not dimple the timing cover or weld to the inside so I may just go with the .012". Max end play is usually around .010" but I don't see another .002" causing problems. What do ya think?
Posted By: Stanton
Re: Comp Cams cam button - 04/06/15 03:34 PM
Cut a small piece of the appropriate thickness of feeler gauge and put it in behind the button. But .012 isn't the end of the world !!
Posted By: gss
Re: Comp Cams cam button - 04/20/15 01:13 AM
Ok finally have some time to get back to this engine build.
From what I have read, it sounds like I need to fill the gap between the water pump and the timing cover to keep the cam from bowing out the timing cover. I could tack on some sort of metal spacer to the timing cover with a MIG welder. Would that create some distortion that would alter the cam end play?
It wouldn't take much to mess it up when we are talking a few thousandths. Would a little duraglass or epoxy putty between the water pump and timing cover work?
From what I have read, it sounds like I need to fill the gap between the water pump and the timing cover to keep the cam from bowing out the timing cover. I could tack on some sort of metal spacer to the timing cover with a MIG welder. Would that create some distortion that would alter the cam end play?
It wouldn't take much to mess it up when we are talking a few thousandths. Would a little duraglass or epoxy putty between the water pump and timing cover work?
Posted By: Stanton
Re: Comp Cams cam button - 04/20/15 02:14 AM
Quote:
Would a little duraglass or epoxy putty between the water pump and timing cover work?
Absolutely !! Stick a piece of saran wrap to the timing cover first so it only sticks to the water pump.