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

[skip_168]

Originally Posted by SC2150

We check the pin depth...and I assumed every one else does as well. Very simple and obvious if it protrudes.

I had to go look again, on Porsche engines the pin has plenty of room given that we have infinite cam timing that we, as engine builders, have to set.. Porsche pins have a threaded hole in them to allow is to pull them out of the cam and gear assembly as well.
It is completely obvious if they are protruding, as well as a weird "feel" when torquing the nut down. Plus, we add blue lock-tite as well..

Originally Posted by SC2150

On the single blot, I agree that if the pin did protrude then the bolt will not hold as designed....but if correct we have single bolt cams on Ford mod motors holding 800-900 plus HP with never an issue....but that is an overhead cam design. On the Maseratti we have in the shop the cams are also single bolt and NO dowel pin....and the engine I am rebuilding right now is the same basic one used at Lemans in the day (early 60's).

I agree, single bolt applications are fine.. Porsche has had them since the late 60's.

Originally Posted by SC2150

I think most are missing the point here. Modifying and engine is not a simple "buy the part and bolt it on", these things are easy and obvious to check for and assemble correctly if you are an experienced engine builder so the failures I have followed to date (we have had zero....and we build race & performance engines all the time from scratch) have all appeared to be assemble error and not something I would blame on Comp or any cam manufacturer. The various timing chain/gear kits are all different (the after market ones) and it is standard to inspect fit , degree the cam, and check for proper PTV clearance. As stated before, there are far to many shops popping up that are taking on motor work w/out the properly trained engine builders in house. Many are "bolt on" techs. So I stand by my staement that the single bolt is fine and safe if installed properly. Make a mistake in ANY area of engine assy and you have catastrophic results.

I agree 100%.. there is a great deal of math when building engines.. I worked in an air conditioned clean room to build air cooled flat six Porsche engines. I could lock the doors, work uninterrupted, and it took me about 50 hours to build a 3.0 liter with no mods, or almost 100 hours on a 3.6 twin turbo with all the fixins.. which made us the exception in the industry. People would not even think of touching a Porsche engine, not even certified mechanics would experiment with a Porsche. But a small block chevy? anyone with a wrench would jump right in..

[skip_168]

Originally Posted by themossman

I was going to post this question the other day...but I had to cut out quickly...

As far as a hypothesis....could a rocker/rod/valve failure lead to the cam 'seizing' or becoming locked in place (even for a split second) and the force of the crank on the timing gear cause great enough force on the cam bolt(and pin) so that it would exceed the cam bolt torque?

Usually if you have a valve train failure, the cam will either break, or keep on turning & you will loose the cylinder where the valve train failure occurred.

When you have a breakdown in the timing relationship between the crankshaft and the valve train, the engine keeps turning and damages most or all of the valves in all of the cylinders, not just one...

[SUX2BU]

Everyone mentioning that other car companies use single bolt cams, are those set ups using timing belts or chains? There is a huge difference.

[Andy@Livernois]

I have not read the whole thread, but definitely saw all of the carnage. I must say I feel your pain on this one. Luckily we have never had a problem, but one thing I find odd is the amount of people defending a single bolt camshaft. While I know most of you are looking for the item that failed first, and I understand the reasoning behind it, it still remains that the single bolt cam COULD have caused this issue. Why anyone would want to run this risk is beyond me. For $40-50 dollars the cam bolts and sprocket wouldn't even be part of this discussion. And while we can't guarantee that it wouldn't have broken still, it would have been one less suspect in this investigation.

I think at this point, you will never know what really happened first. I know that is a hard thing to deal with, everyone wants to know why, we want (for lack of a better term) closure, we want to find that smoking gun. Could a valve have floated, and caused the initial problem, then causing the pin to fail? yes. could something else have failed first, causing this to happen? yes. but, I feel we have to look at the most probable cause here. Single bolt cams are never as good as a cam with multiple bolts. I posted this in another thread just this week, but ford guys have been fighting this forever. It's a real problem, unfortunately they have to solve it by adding a second pin as no manufacture makes a 3-bolt cam for a ford engine.

To those comparing it to a OHC engine, remember how much more force is on the cam in an LS engine as it is operating 16 valves, all the pushrods, lifters, and springs that have way more pressure than an OHC engine. plus the high ratio rockers on an LS puts a lot more pressure than normal. Simply put, it's not an apples to apples comparison.

Please let this be a lesson for all to learn from. As I said, while there is no guarantee that we wouldn't be reading this thread even if the OP had a 3-bolt cam, it would be one less possibility for a cause, and maybe would let us get a definitive answer on what caused the issue. Spend the small amount of extra money and convert over. There is a reason the LS7 still uses a 3-bolt cam.

[SC2150]

skip....your a breath of fresh air here with so many differing opinions! Our engine roomis a A/C'd clean room as well, lock me in and I get stuff done....but it is all very time consuming.

The Porsche motors are amazing the power I have seen them put out...and the durability. I have built many different european race/performance motors but never a porsche. I have owned a 911, a 928, and a 944 in my past years and rebuilt motors & transaxles on them with success....but never did much as far as the mods. I have a ton of respect for any that wrench on them.

And the post above that:

"This. None of the top LS builders use one bolt cams, they all switch the LS3 to 3 bolt style. Its a known weakness in the LS3."

has me a little confused, but I don't know who is on that list.....certainly not myself or many of the other race shops I know & respect.....I stand firm that the single bolt is NOT a weakness....only the proper installation.

[skip_168]

Originally Posted by SUX2BU

Everyone mentioning that other car companies use single bolt cams, are those set ups using timing belts or chains? There is a huge difference.

Porsche uses two and sometimes three chains..

Originally Posted by SC2150

skip....your a breath of fresh air here with so many differing opinions! Our engine roomis a A/C'd clean room as well, lock me in and I get stuff done....but it is all very time consuming.

The Porsche motors are amazing the power I have seen them put out...and the durability. I have built many different european race/performance motors but never a porsche. I have owned a 911, a 928, and a 944 in my past years and rebuilt motors & transaxles on them with success....but never did much as far as the mods. I have a ton of respect for any that wrench on them.

And the post above that:

"This. None of the top LS builders use one bolt cams, they all switch the LS3 to 3 bolt style. Its a known weakness in the LS3."

has me a little confused, but I don't know who is on that list.....certainly not myself or many of the other race shops I know & respect.....I stand firm that the single bolt is NOT a weakness....only the proper installation.

Porsche was fun... a history of 1100 hp out of 3-4 litre engines that needs to run all out for 24 hours... good times..

the 944 & 928's were fun cars too...

the 944 was designed by Audi, and the 928 by Mercedes.. Porsche always wanted to stay away from water cooled engines until they had to due to emissions concerns... but they needed to because of the design limitations of air-cooling..


A lifetime spent with Porsche cars and boxsters, but I always loved american muscle cars.. so here I am in the camaro world...


I gotta say I was very impressed with the 3.6L engine in the camaro..

[Nvincent4708]

Originally Posted by SC2150

Nvincent, you are lucky to have had a Dad pass that along. Exactley how I got my start. It's a lost art though, very rare that Father/Son talents are passed down anymore....and the tech schools teach parts changing as that is the efficient way for a dealer service dept to get cars in & out.

My grandfather was a mechanic all his life, from the 1920's to the 80's when he retired and my Dad was a stockcar driver in the 50's.

You have knowledge that is hard to be taught even today unless at a specialty school.

Thanks!

I'm trying to keep it alive. I'll try to teach one of my kids if i have one, or one of my friends kids.

For now, i'll use my knowledge to build a mean street machine.

[Huggerorange73]

Originally Posted by Andy@Livernois

I have not read the whole thread, but definitely saw all of the carnage. I must say I feel your pain on this one. Luckily we have never had a problem, but one thing I find odd is the amount of people defending a single bolt camshaft. While I know most of you are looking for the item that failed first, and I understand the reasoning behind it, it still remains that the single bolt cam COULD have caused this issue. Why anyone would want to run this risk is beyond me. For $40-50 dollars the cam bolts and sprocket wouldn't even be part of this discussion. And while we can't guarantee that it wouldn't have broken still, it would have been one less suspect in this investigation.

I think at this point, you will never know what really happened first. I know that is a hard thing to deal with, everyone wants to know why, we want (for lack of a better term) closure, we want to find that smoking gun. Could a valve have floated, and caused the initial problem, then causing the pin to fail? yes. could something else have failed first, causing this to happen? yes. but, I feel we have to look at the most probable cause here. Single bolt cams are never as good as a cam with multiple bolts. I posted this in another thread just this week, but ford guys have been fighting this forever. It's a real problem, unfortunately they have to solve it by adding a second pin as no manufacture makes a 3-bolt cam for a ford engine.

To those comparing it to a OHC engine, remember how much more force is on the cam in an LS engine as it is operating 16 valves, all the pushrods, lifters, and springs that have way more pressure than an OHC engine. plus the high ratio rockers on an LS puts a lot more pressure than normal. Simply put, it's not an apples to apples comparison.

Please let this be a lesson for all to learn from. As I said, while there is no guarantee that we wouldn't be reading this thread even if the OP had a 3-bolt cam, it would be one less possibility for a cause, and maybe would let us get a definitive answer on what caused the issue. Spend the small amount of extra money and convert over. There is a reason the LS7 still uses a 3-bolt cam.

The bolded part is what concerns me.....it'll drive me INSANE!

[DevilsReject97]

Hugger,

I've read this entire thread from start to finish and every time I look at these pictures I just want to throw up. I know that I could not have handled it as well as you have apparently done so, as I would have definitely lost my cool oh....30 seconds after it happened....

I am very glad that you have been able to get relatively close to determining what really led to the problem. Granted, you may never be able to say 100 percent that this did that....but all the information you've been able to add, create, and update has been huge for the rest of us in the Camaro community.

To everyone who has been chipping in with quality knowledge and suggestions, I also want to say thanks. Your input and comments have given me a better understanding of my wonderful car, and in some ways, given me ideas of what not to do moving forward.

I'd also like to say to Kelly, that you sir, are a freaking awesome individual. Not only is your car one of my favorite Camaros in the world, but you are just a great overall person. Just your sacrifice alone as a soldier is worth a cold beer and a handshake. What you did for Hugger by bringing him home is truly a step beyond. Thanks...

[Elykson]

Just wanted to bump this to keep it fresh and wondering if there are any updates? I missed you at the movie, Mike.

[Huggerorange73]

Originally Posted by DevilsReject97

Hugger,

I've read this entire thread from start to finish and every time I look at these pictures I just want to throw up. I know that I could not have handled it as well as you have apparently done so, as I would have definitely lost my cool oh....30 seconds after it happened....

I am very glad that you have been able to get relatively close to determining what really led to the problem. Granted, you may never be able to say 100 percent that this did that....but all the information you've been able to add, create, and update has been huge for the rest of us in the Camaro community.

To everyone who has been chipping in with quality knowledge and suggestions, I also want to say thanks. Your input and comments have given me a better understanding of my wonderful car, and in some ways, given me ideas of what not to do moving forward.

I'd also like to say to Kelly, that you sir, are a freaking awesome individual. Not only is your car one of my favorite Camaros in the world, but you are just a great overall person. Just your sacrifice alone as a soldier is worth a cold beer and a handshake. What you did for Hugger by bringing him home is truly a step beyond. Thanks...

To all of it!

Originally Posted by Elykson

Just wanted to bump this to keep it fresh and wondering if there are any updates? I missed you at the movie, Mike.

Kyle...I was working Friday night, couldn't make it!

The only update I've got to offer at this point is the direction I'm moving in to get the car back on the road. A crate LS3 is going back in the car....as tempting as it is to stuff a cam in it before I drop it in there...I'm going to pass. With the recent run of luck I'm on, something would let loose and I'd be screwed again. I'm going to leave the car alone until the 2 yr/24,000 mile engine warranty expires....bolt ons only for now!

[Huggerorange73]

So I thought about this one last time....I think I may have a possible chain of events.

When the car was shifted into second it was at or very close to redline, at this point, I think the connecting rod for piston # 1 broke in the middle of the rod. The piston kissed the valve while the remainder of the rod still attached to the crankshaft whipped around and took out the lifters for cylinder # 2 causing the valvetrain to lock up and shearing the locating pin off the crankshaft....once the cam timing was lost all the valves then kissed the pistons, the worst case being cylinder # 7 which broke apart the piston while leaving the connecting rod & wrist pin still intact and operable.

If you keep in mind all this was happening @ 6400 RPM I think this fits the carnage that I'm seeing. What do you guys think?

I'm hoping to have the car back on the street by the third week of July....I've had an enourmous amount of help from my Camaro brothers & sisters and my family...there's no way I can thank everyone enough.

Hopefully this thread & images helped alot of people learn more about what's under the hood and how it works, not to mention the destruction caused when things go south!

[Toasty]

Originally Posted by Huggerorange73

So I thought about this one last time....I think I may have a possible chain of events.

When the car was shifted into second it was at or very close to redline, at this point, I think the connecting rod for piston # 1 broke in the middle of the rod. The piston kissed the valve while the remainder of the rod still attached to the crankshaft whipped around and took out the lifters for cylinder # 2 causing the valvetrain to lock up and shearing the locating pin off the crankshaft....once the cam timing was lost all the valves then kissed the pistons, the worst case being cylinder # 7 which broke apart the piston while leaving the connecting rod & wrist pin still intact and operable.

If you keep in mind all this was happening @ 6400 RPM I think this fits the carnage that I'm seeing. What do you guys think?

I'm hoping to have the car back on the street by the third week of July....I've had an enourmous amount of help from my Camaro brothers & sisters and my family...there's no way I can thank everyone enough.

Hopefully this thread & images helped alot of people learn more about what's under the hood and how it works, not to mention the destruction caused when things go south!

Leaving out the cam bolt tightened against the alignment pin? I don't think I can buy into an argument that leaves that out of the equation completely...Or are you thinking that the rod going south was contributed to by the extra vibrations in the rotating assembly? I guess it's possible that the rod fatigued/stretched enough to break, but find it far less likely a scenario in my head... any thought to measuring the rods that are still complete in the motor to see how they compare to spec?

[Huggerorange73]

Originally Posted by Toasty

Leaving out the cam bolt tightened against the alignment pin? I don't think I can buy into an argument that leaves that out of the equation completely...Or are you thinking that the rod going south was contributed to by the extra vibrations in the rotating assembly? I guess it's possible that the rod fatigued/stretched enough to break, but find it far less likely a scenario in my head... any thought to measuring the rods that are still complete in the motor to see how they compare to spec?

The pin may have been touching the pin...but it's unlikely that the engine was beat to death on the street, strip and dyno for 1,000 miles before that pin broke.

The LS3 is mass produced....it's not unheard of for a rod to fail. It just seems like a reasonable chain of events that lead to the mess that is currently my engine.