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

[trm0002]

Originally Posted by Camarowguy

I'm not here to argue with you by any means, but I know for a fact that you are incorrect. I had a 350 that I had for a spare engine while I build my big cube motor. It had a pretty healthy cam in it (242/248@.050 .600+ lift) and so I fly cut the pistons. Evidently I didn't fly cut them enough. When I pulled the engine out to put my big engine in....I could clearly see where the valves contacted the pistons on a regular basis. Did mine sound like a diesel? Umm, not at all. So that goes to show what you "think" is not always correct. It ran just fine also. 12.05. @117mph on motor with hankook radials. Why didn't it fail? My guess is I didn't give it long enough. Why didn't it run like shit? Because Im guessing contact was only at higher rpm.

I don't disagree at all with what you're saying my friend. That said, I just made an opinion based on Mike's cam replacement- not overly aggressive from what he said- that valve clearance wouldn't have been an issue unless the timing was off. If the timing was off, wouldn't he have immediately noticed issues?

[BlackJacket]

[Camarowguy]

Originally Posted by trm0002

I don't disagree at all with what you're saying my friend. That said, I just made an opinion based on Mike's cam replacement- not overly aggressive from what he said- that valve clearance wouldn't have been an issue unless the timing was off. If the timing was off, wouldn't he have immediately noticed issues?

If cam timing was off, I doubt it would run correctly...or even run at all. I'm not so sure how "off" you can get the timing and the engine still run....but most engines I've encountered wouldn't run with a tooth off. My theory is this: the ls3 has no valve reliefs, so that right there would scare me to put a cam in without checking the valve to piston clearance. Also, it's a standard transmission car...you can over rev them easier and also accidentally mechanically over rev it...in which the rev limiter would do nothing to protect the engine in that case. The op never mentioned that he had ever done this so who knows. Also, the rev limiter had be raised. Another strike against the situation. I feel like there are many factors that come into play with this and make the ptvc issue a probable cause. Think about this one small tidbit. What if the valve springs weren't shunned to the correct installed height. Say the shop just put them on. Then it's missing say 20lbs of seat pressure and maybe 30-50lbs open pressure. Everyone knows the valves are huge and heavy, so that makes the spring setup that much more important.

He could possibly had acceptable ptvc, but factor in numerous redound shifts with incorrectly set up springs or possibly weak springs and that will explain why the valves were smacking the pistons. I also feel confident that if the pin broke and the valves contacted (which they would) it wouldnt be so pronounced as in his pics. To me it looks like it's been happening for Sind time now....not just a split second during the failure. I have no doubt the cause of failure is caused by the valvetrain.

[Huggerorange73]

I'm not sure I'm buying into the PTV theory as cause for failure 100%

My cam is a .571/.590 228/240 on a 113 LSA....that's more than enough clearance on PTV.

The car has never been overrevved outside of when the output shaft let loose.

I do agree that something went haywire with the valve timing.....Friday I'm yanking the balancer off and we'll have more info then. However, that will be all the info we'll ever have.....enough to solve the mystery? Who knows...

[Huggerorange73]

Originally Posted by Camarowguy

Out of curiosity, how many l99's have had a failure like this?

So far almost all of the blown engines have been LS3s....

[PQ]

L99s have the lifter issue. Maybe it's just because the L99s give more warning.

Mine is transforming into an LS3 right now.

[Huggerorange73]

Originally Posted by PQ

L99s have the lifter issue. Maybe it's just because the L99s give more warning.

Mine is transforming into an LS3 right now.

You'll be fine PQ!

[mikeSS]

i might be wrong on this, but i feel that more people are putting cams into LS3s then l99s. i am not sure about FI. as i do not read those threads that often. but maybe we are seeing more problems with LS3s right now because they are getting modded more. in term of internal mods.

[SUX2BU]

Originally Posted by mikeSS

i might be wrong on this, but i feel that more people are putting cams into LS3s then l99s. i am not sure about FI. as i do not read those threads that often. but maybe we are seeing more problems with LS3s right now because they are getting modded more. in term of internal mods.

Exactly.

[mercedestech]

Forgive me if it's been mentioned already, but has anyone had a failure like this with the three bolt cam setup? And @ Huggerorange73....hope everything works out...really sorry to hear about your car.

[S-eatin-grin]

I sure hope it's nothing LS3 specific...One thing to consider it that the driver of an LS3 can have a lot influence on the motor with lugging the car, shift points, overreving with down shift...The auto is a little more user friendly and thus may be more engine friendly. I'm not saying this had anything to do with Mike's case but it may be an influence in other LS3 drivers in general....

[Camarowguy]

Originally Posted by PQ

L99s have the lifter issue. Maybe it's just because the L99s give more warning.

Mine is transforming into an LS3 right now.

It won't completely be an ls3....you'll be a step ahead tho...you'll have valve pockets.

[Huggerorange73]

Originally Posted by mikeSS

i might be wrong on this, but i feel that more people are putting cams into LS3s then l99s. i am not sure about FI. as i do not read those threads that often. but maybe we are seeing more problems with LS3s right now because they are getting modded more. in term of internal mods.

I think you're spot on with this.

Originally Posted by mercedestech

Forgive me if it's been mentioned already, but has anyone had a failure like this with the three bolt cam setup? And @ Huggerorange73....hope everything works out...really sorry to hear about your car.

Thanks....I'm getting alot of help from my friends!!! It'll be on the road soon!

Originally Posted by S-eatin-grin

I sure hope it's nothing LS3 specific...One thing to consider it that the driver of an LS3 can have a lot influence on the motor with lugging the car, shift points, overreving with down shift...The auto is a little more user friendly and thus may be more engine friendly. I'm not saying this had anything to do with Mike's case but it may be an influence in other LS3 drivers in general....

It's very possible that all your points are right.....Friday when I get that cover off we'll have even more information to mull over.

Originally Posted by Camarowguy

It won't completed be an ls3....you'll be a step ahead tho...you'll have valve pockets.

As long as you do your homework the flat pistons don't hurt ya.....

[Camarowguy]

Huggerorange, I know your getting annoyed at my diagnosis. And I understand why. But the harsh reality is you don't know for sure you had clearance. You didn't check it yourself (no offense meant). You probably have alot of faith in your shop that did the cam install for you (I'm not bashing them either, I've made mistakes too.) and that's ok....but I feel confident what happened. It's not saying they don't know what they are doing either, they may have done this setup time and time again with no issue. But I'm here to tell you, even tho two engines are the same....they still are not exact. That's why some same cars are faster or slower.

Your cam may not have monster lift, but it does have a good amour of duration on the exhaust. A simple thing as not degreeing the cam could cause issues too. The cam manufactorer could have ground the cam a little off (I used to work for cam motion, and it's possible) bottom line is man, I'm sorry for your loss by all means, but after seeing your pics, I feel confident what happened because I have seen it a few times. I wouldn't be scared to put a cam in your new engine, I would however, degree it on the stand and check the piston to valve clearance. Also, make sure Your springs are correct. I myself, when setting up a set of heads, like to find a set of stiffer springs that what recommended. Let me elaborate slightly. Say your cam is recommended with 160lbs seat pressure and 350 open pressure. I like to add about 20lbs on the seat and around 30-50lbs open pressure. It makes me feel better. I do like to rev my engines to the moon. My 383sbc was shifted at 7800rpm on an everyday basis. I drove it everyday and smashed it more than I should have!