My Camaro went home to Oshawa to die......

[2SSRS@Gen5diy]

Originally Posted by getarz4u15ster

I have the card somewhere i'm going to have to dig it up. I looked up the grind number you gave me, it has different spec on it.. however that doesn't mean it wasn't part of a bad batch that comp made of single bolt cams. Here's the scoop i got from my speed shop (Maryland Performance). The owner has been doing business with comp for a while, and they will NOT admit to the general public that they had a issue with a batch of cams, however they did admit to him that they have seen some issues with single bolt cams in with this type of failure are narrowing it down to single bolt grinds between certain dates.. Still there is no way tell which ones are bad, and which ones aren't... till this happens..

Problem is, these pins are not made to withstand the 500hp where demanding from them, a lot of machinist are putting a second dowl in the cam's just to be sure this doesn't happen even on three bolt cams.. Cheap insurance to keep from having this type of failure..

Here's my Cam card btw..
http://www.compcams.com/Company/CC/c...csid=1427&sb=0

Thanks for looking for the info, is there a way you can find the SN#?

[assasinator]

having read throught this thread, i have an opinion. on modulars, there is NO indexing pin on early 4v's and most big cammed 4v's. there is more than enough force on the gear to cam interface to hold 8,000 rpms.

IMO something stopped the cam and tweaked its phasing. banging valves finished the rest. in the old days SBC will break the cam in two.

it would be very easy to broach the gear and end mill the cam to eliminate the possibility of the cam moving. of course if a lifter sticks it will snap the cam.

[IROCanSS]

Originally Posted by assasinator

having read throught this thread, i have an opinion. on modulars, there is NO indexing pin on early 4v's and most big cammed 4v's. there is more than enough force on the gear to cam interface to hold 8,000 rpms.

IMO something stopped the cam and tweaked its phasing. banging valves finished the rest. in the old days SBC will break the cam in two.

it would be very easy to broach the gear and end mill the cam to eliminate the possibility of the cam moving. of course if a lifter sticks it will snap the cam.

Did you read the whole thread? Its pretty obvious what happened from looking at the pictures. The cam bolt was tightened onto the pin. You can see in one picture exactly where it was tightened to on the back of the bolt shoulder. This would cause uneven force on the cam gear and cause a slight vibration. That vibration would be enough to weaken the pin and eventually lead to this.

I am in complete agreement that the gear to cam force would have been enough to hold your claimed 8000 RPM. In this case, the pin isnt there to hold anything, just to line it up. The torque on the bolt holds the gear to the came. The force was not evenly distuributed over the gear in this case.

I'd say its cut and dry... only question now, whos to blame???

[Huggerorange73]

Originally Posted by getarz4u15ster

To the OP.. Woah... looks you had a case of me... only at higher RPM.. ( i was sitting at idle). "DID NO ONE READ MY POSTS ABOUT NOT BUYING A SINGLE BOLT CAM!!!!" I was the "the other guy" someone posted pics of an my cam pin that broke off) What happens on single bolt camshafts (or at least in my case) was when the pin broke the cam spun 90 somthing degrees advance.. soo on our cars the rotating assembly turns clockwise, which happens to be also righty tighty.. welllllll.... when the cam spun after the pin broke the bolt tightened up on the cam again causing the cam to rotate out of sync with the crank.. we all know what happens next (interference) with everything.. Lifters, Pushrods, Pistons, Valves, Cam lobes, you name it's toast.. you get the point.. i'm guessing the reason your lifter is stuck in the lifter bore is is because the one of the cam lobes smacked the side of the lifter at the same time your piston hit the valve causing the lifter roller assembly to get lodged in the bore...

So hugger... here's the good news.. you get to build it bigger and better than before.. here's the bad news... it's gonna cost some money !!! If your cam gear looks like mine you need to call comp and demand they replace the Cam with a "Cam of your choosing", 3 bolt this time. I talked to "red" from the warranty department (he is the warranty manager at comp).

I'm sorry this happened to you... I know that sickening feeling you have in your gut when this stuff happens.. if you have any questions... anyone let'em fly..

I may need some more info from you in the near future.....I'll be on the phone with Comp tomorrow morning.

Originally Posted by Ajaxx

Thats why I went with a three bolt.....

Lesson learned.

Originally Posted by 2SSRS

Thanks for looking for the info, is there a way you can find the SN#?

That would be huge if you could find that!

Originally Posted by assasinator

having read throught this thread, i have an opinion. on modulars, there is NO indexing pin on early 4v's and most big cammed 4v's. there is more than enough force on the gear to cam interface to hold 8,000 rpms.

IMO something stopped the cam and tweaked its phasing. banging valves finished the rest. in the old days SBC will break the cam in two.

it would be very easy to broach the gear and end mill the cam to eliminate the possibility of the cam moving. of course if a lifter sticks it will snap the cam.

The cam still spins freely...all the rollers on the lifters are in good working order without any marks.

Originally Posted by jrhaus76

Did you read the whole thread? Its pretty obvious what happened from looking at the pictures. The cam bolt was tightened onto the pin. You can see in one picture exactly where it was tightened to on the back of the bolt shoulder. This would cause uneven force on the cam gear and cause a slight vibration. That vibration would be enough to weaken the pin and eventually lead to this.

I am in complete agreement that the gear to cam force would have been enough to hold your claimed 8000 RPM. In this case, the pin isnt there to hold anything, just to line it up. The torque on the bolt holds the gear to the came. The force was not evenly distuributed over the gear in this case.

I'd say its cut and dry... only question now, whos to blame???

I say we blame Dan.

[getarz4u15ster]

Originally Posted by 2SSRS

Thanks for looking for the info, is there a way you can find the SN#?

Hmmm, now your asking me to move mountains.. i'm thinking not.. but i might have it in the garage somewhere...

[IROCanSS]

Originally Posted by Huggerorange73

I say we blame Dan.

... It was all Dan's fault from the beginning!

[skip_168]

Sounds like some people need to go back to "cam School"

Originally Posted by Toasty

LS3 pistons are flat top, L99's have reliefs or pockets in the piston head to accomodate the VVT range of timing.

good clue here...

Originally Posted by Camarowguy

^^^thanks! Alot of people are forgetting this. And it's my whole point. The l99 can accommodate a larger cam because of the valve reliefs in the pistons. Which is a large reason why we see more ls3 failures. Make sense?

warmer...

Originally Posted by mikeSS

wait so we will never know what happen first ?

absolutley not..

Originally Posted by GMGP5X

Web M.D. for engines.

and another website is born...

Originally Posted by Camarowguy

The pin breaking wasn't the cause. It was a result of what happened. My .02

warmer still!

[GEN-IV]

Originally Posted by jrhaus76

Did you read the whole thread? Its pretty obvious what happened from looking at the pictures. The cam bolt was tightened onto the pin. You can see in one picture exactly where it was tightened to on the back of the bolt shoulder. This would cause uneven force on the cam gear and cause a slight vibration. That vibration would be enough to weaken the pin and eventually lead to this.

I am in complete agreement that the gear to cam force would have been enough to hold your claimed 8000 RPM. In this case, the pin isnt there to hold anything, just to line it up. The torque on the bolt holds the gear to the came. The force was not evenly distuributed over the gear in this case.

I'd say its cut and dry... only question now, whos to blame???

If this is the case, the person that assembled it should have caught it. While parts like this shouldn't make it into the hands of customers, it is the aftermarket after all and quality varies enormously. A good engine builder would catch it, but an occasional builder may not.

Gather up all of the good parts, and build something better than GM ever dreamed of!

[getarz4u15ster]

Originally Posted by Huggerorange73

Dug a little deeper today....found # 1 plug wasted as well...chunks of metal in the intake as well.

I really need to figure out why the hell this happened.

According to your pictures.. looks like you had valve springs replaced.. GREAT.. on the other hand what spring set did you buy?

There were two contributing factors to my failure.. one caused the other i believe.

#1... When i put the springs on (didn't know at the time) the outter spring wasn't sitting completely flush with the spring seat. Why you ask.. come to find out the kit that comp sells for for our cars require the spring seats to be cut to correct diameter but doesn't say that in their spec sheet. Now we aren't talking a a huge gap between where the spring sat, and it actually resting on the spring seat however its enough to cause coil bind at even moderate rpm ranges. Instead of my getting my .630 lift on my exhaust site.. i was only seeing about .525 of it... (according to the machinist that took my head and redid after "the incident".

#2 Once i found out i had coil bind on every single valve.. it would stand to reason that the added stress all the way through the valve train (Cam, pushrods, lifters etc... put even more stress on cam pin (that is only used for alignment purposes anyway, because the bolt couldn't sit flush with the cam gear) cause it to loosen and shear off, the rest... well you know.

conclusion for me at least.. it was a combo between lack of information on the spring seat info (comps diameter specs show stock numbers), and a pin that was a couple thousandths to long... the combination of the two caused the pain. I feel for ya dude.. however we have learned some valuable lessons... if you want to be safe go with the following..

Three Bolt cam
Three Bolt cam gear (got mine from LFP) which comes with the LS2 chain tensior (another weak point in the LS3)
Katech's C5-R chain
XFI series cam (ramp rates are a little slower than the LS-R cam line (but better overall spring life).
A good set titanium springs, locks, and retainers (i have patriot .660's)
and while your at since you have to get a new short block anyway... (just build the bottom end forged.. =O)

[garcmol]

Just caught up. So, if I'm absorbing this right, the bolt was torqued against the cam pin and not the gear? I say this since the pin has obviously dug into the cam bolt. This would tell me that the cam bolt was NEVER really torqued flush against the gear. Wouldn't that throw the balance of that gear way way way off? I would have to agree that this started the whole thing.

I may be repeating a lot of conclusions. This is really so I understand correctly.

[2SSRS@Gen5diy]

Originally Posted by getarz4u15ster

According to your pictures.. looks like you had valve springs replaced.. GREAT.. on the other hand what spring set did you buy?

There were two contributing factors to my failure.. one caused the other i believe.

#1... When i put the springs on (didn't know at the time) the outter spring wasn't sitting completely flush with the spring seat. Why you ask.. come to find out the kit that comp sells for for our cars require the spring seats to be cut to correct diameter but doesn't say that in their spec sheet. Now we aren't talking a a huge gap between where the spring sat, and it actually resting on the spring seat however its enough to cause coil bind at even moderate rpm ranges. Instead of my getting my .630 lift on my exhaust site.. i was only seeing about .525 of it... (according to the machinist that took my head and redid after "the incident".

#2 Once i found out i had coil bind on every single valve.. it would stand to reason that the added stress all the way through the valve train (Cam, pushrods, lifters etc... put even more stress on cam pin (that is only used for alignment purposes anyway, because the bolt couldn't sit flush with the cam gear) cause it to loosen and shear off, the rest... well you know.

conclusion for me at least.. it was a combo between lack of information on the spring seat info (comps diameter specs show stock numbers), and a pin that was a couple thousandths to long... the combination of the two caused the pain. I feel for ya dude.. however we have learned some valuable lessons... if you want to be safe go with the following..

Three Bolt cam
Three Bolt cam gear (got mine from LFP) which comes with the LS2 chain tensior (another weak point in the LS3)
Katech's C5-R chain
XFI series cam (ramp rates are a little slower than the LS-R cam line (but better overall spring life).
A good set titanium springs, locks, and retainers (i have patriot .660's)
and while your at since you have to get a new short block anyway... (just build the bottom end forged.. =O)

Wow so there springs at 2X the cost need spring seats to be cut, And it does not say that any where, glad i did not buy a cam from them or springs.

[getarz4u15ster]

Originally Posted by 2SSRS

Wow so there springs at 2X the cost need spring seats to be cut, And it does not say that any where, glad i did not buy a cam from them or springs.

The specs from thunder racing (where i bought the springs show Comp's product description as the following)

Comp Cams 26926 Ultra Dual Valve Springs; Designed for GM LSr Camshafts, .675 Lift, 1.290" OD, set of 16

Developed in conjunction with the new LSR™ Camshaft Series for GM LS engines, the #26926 Ultra Dual Valve Spring is the most high-tech of all COMP Cams® valve springs. With a host of high-end race design features and Super Clean® wire material, this lightweight, small O.D. dual valve spring is capable of controlling extremely aggressive profiles with lift up to .675".

• Designed to fit the stock valve spring pocket (without machining) and stock valve length

• Super Clean® wire material for unsurpassed resistance to fatigue, load loss and breakage



however if you go to another place on their site.. same springs.. see the following link

http://www.compperformancegroupstore...Category_Code=

The inner spring also had the problem of fitting around the spring guide that's IN the head.. those would need to be replaced to something smaller to accommodate the smaller spring inside...again lack of CORRECT information here is a BIG problem.

So it's just as much my fault for not doing thorough research as it is comp's or whoever elses.. =o/

[f5journal]

Very informative thread...I've been reading all along. I feel for you, good luck

[Huggerorange73]

Originally Posted by getarz4u15ster

According to your pictures.. looks like you had valve springs replaced.. GREAT.. on the other hand what spring set did you buy?

I used the Patriot springs instead of the Comp springs...score one for me!

Originally Posted by garcmol

Just caught up. So, if I'm absorbing this right, the bolt was torqued against the cam pin and not the gear? I say this since the pin has obviously dug into the cam bolt. This would tell me that the cam bolt was NEVER really torqued flush against the gear. Wouldn't that throw the balance of that gear way way way off? I would have to agree that this started the whole thing.

I may be repeating a lot of conclusions. This is really so I understand correctly.

I think this is what happened.....still sorting through all the clues though.

Originally Posted by 2SSRS

Wow so there springs at 2X the cost need spring seats to be cut, And it does not say that any where, glad i did not buy a cam from them or springs.

Not a good thing when brand new springs need to be hacked up....

Originally Posted by f5journal

Very informative thread...I've been reading all along. I feel for you, good luck

Thanks!