Thoughts on my cam/timing gear issue.....*Update

[Mike T]

This may be something to look out for, or maybe someone has the solution?

Short block together, new comp roller cam installed, new .005 chain due to line bore for main caps.

After installing the chain I noticed it has 3/16-1/4 slop. This made no sense because the prior .005 chain was actually too tight.

I began rotating the motor to evaluate what was going on and noticed that on the 2nd revolution of the crank the chain slop was at zero (actually in a little bind). I repeated the process and it tightened again on the second revolution of the crank so I knew it was the cam or cam gear.

Fast forward after measuring several cams and gears finally determined that the new comp cam is .011 undersized where the cam gear centers. This causes it to favor whatever side the chain pulls it to before you tighten the bolts.


Tried several times to center it but I'm chasing my tail at this point.....not to mention what a PITA it would be to degree the cam.

This could have been easily overlooked so I'm glad I caught it.

Anyone ran into this before?

 

[haywire4130]

If you have access to a lathe you could have a thin sleeve machined to center it. If you strike out and have access to accurate measuring tools pm me the id and od and length and ill make you one for whatever it costs to mail it to you-

 

[BEATAV8]

At the top of the list is "Factory Engineered Parts". At the bottom of the list we have "Aftermarket Parts".
In the middle we have various levels:
1. Factory Engineered
2. Factory Remanufactured
3. Iron Ore still in the ground
4. Whale Shit on the bottom of the ocean.
5. Aftermarket parts...

As you can see, somewhere below the whale shit is where we find aftermarket parts.

 

[ek02]

If the cam is .011 undersize from a stock cam, maybe return it to Comp if you bought it new. Cam gears are usually a tight fit on the cam. If you bought it used, try a .004 or .005 strip of shim stock available from Goodson.

 

[TURBOELKY]

Wow. Something to tuck away for future reference. Who would have thought!

 

[Mike T]

If you have access to a lathe you could have a thin sleeve machined to center it. If you strike out and have access to accurate measuring tools pm me the id and od and length and ill make you one for whatever it costs to mail it to you-

Very nice offer haywire, it's not often someone will jump right in willing to help like that.
Your offer is much appreciated but I will be getting a replacement cam for the defective one.

It was purchased new a little over a year ago and like so many other things I just got back on it and discovered the problem.

 

[Mike T]

If the cam is .011 undersize from a stock cam, maybe return it to Comp if you bought it new. Cam gears are usually a tight fit on the cam. If you bought it used, try a .004 or .005 strip of shim stock available from Goodson.

Shim of some sort or a cam gear with a smaller ID (probably no such animal) would have been the only to fix it.

 

[Mike T]

Wow. Something to tuck away for future reference. Who would have thought!

Anymore I check, re-check and triple check every new part, more often than not there will be a little problem of some sort.
This one could have been easily overlooked and caused real problems down the road.

 

[haywire4130]

My pleasure, and my offer stands if the cam company gives you the runaround-

 

[Chuck Leeper]

Timing chain "kit".
Kit definition at my shop: "One size fits nothing".
Cc is slowly getting a bad rep from the junk they fail to qc, prior to selling it.

I had a similar exp, w/ a well known cam grinder. Location pin was 12* off. I ran it on the cam Dr, mailed it back, and received a shitty fone call. The asshat said, "who are you, Bob Glidden?". Cancelled the cc charge, and left a shiity review at several forums. Done...

Hopefully, CC will step up...

 

[haywire4130]

Hahaha "Bob Glidden"... classic!

 

[Mike T]

I had a similar exp, w/ a well known cam grinder. Location pin was 12* off. I ran it on the cam Dr

Wasn't sure what the Cam DR was until I googled it. Looks like a handy device you had there Mr Glidden

 

[bison]

Wasn't sure what the Cam DR was until I googled it. Looks like a handy device you had there Mr Glidden

You can check camshafts with a large degree wheel and an indicator. No need for anything else. If the cam is machined wrong send it back. I've had cams re-ground that were off a little and they did so with no problem. The analysis was included when I sent the cam back


Sent from my iPhone using Tapatalk

 

[1952ray]

Timing chain "kit".
Kit definition at my shop: "One size fits nothing".
Cc is slowly getting a bad rep from the junk they fail to qc, prior to selling it.

I had a similar exp, w/ a well known cam grinder. Location pin was 12* off. I ran it on the cam Dr, mailed it back, and received a shitty fone call. The asshat said, "who are you, Bob Glidden?". Cancelled the cc charge, and left a shiity review at several forums. Done...

Hopefully, CC will step up...

Chuck, I have to hand it to you your shit doesn't stink!!!!!

 

[achalmersman]

At the top of the list is "Factory Engineered Parts". At the bottom of the list we have "Aftermarket Parts".
In the middle we have various levels:
1. Factory Engineered
2. Factory Remanufactured
3. Iron Ore still in the ground
4. Whale Shit on the bottom of the ocean.
5. Aftermarket parts...

As you can see, somewhere below the whale shit is where we find aftermarket parts.

This reply is epic and so true about so many things lmao

Sent from my VS990 using Tapatalk

 

[earlbrown]

Interesting tidbit I learned working at a machine shop....

Heavy Duty Reynolds wrap is exactly .001" thick. After drunkenly measuring the foil while grilling at the shop there's always a big chuck next to the surfacing machine now.

I don't know if it would take exactly .002" to make your gear run concentric, but 1 thou is a nice even number.

 

[Mike T]

Good info Earl. My situation would have actually required .005 to center the gear.
The good news is that Comp replaced the cam after verifying my findings. There was no "song and dance" they simply sent me a new one.
My vendor set it up so that I sent the defective cam to Comp and they sent me a new one.


This exchange was a nice gesture because it was purchased over a year ago and the problem was only recently discovered.
For others interested in this thread it sounds as if this defect is not going to be a widespread problem. A while back they discovered a few cams with this defect and they never left the facility. The defective cams were accounted for and it is quite possible this was the only one that got through.

 

[Pronto]

I've been the "lucky" one that got the defective parts that slipped though "inspection". Not fun.

 

[earlbrown]

G The defective cams were accounted for and it is quite possible this was the only one that got through.

That's Comps 'go to' reply when they are forced by facts to admit a mistake.

Glad you got it sorted out without a bunch of BS

 

[BEATAV8]

I've also been a lucky one that received a one of a kind defective roller cam.....

Here's a hint that might help. Slide the cam into place nice and flush up against the thrust. install your lifters and rotate the camshaft. inspect for any instances of lifters hitting adjacent lobes. if the thrust surface is machined incorrectly you will find some unwanted hits.