Which will be more harmful on a motor?

1. Large cam and heads?

2. Supercharger?

I would think the cam and heads would put some strain on the valve train and the blower would be all of the above. But I'm not a mechanic so only guessing. What do you think?

Which will be more harmful on a motor?

1. Large cam and heads?

2. Supercharger?

I would think the cam and heads would put some strain on the valve train and the blower would be all of the above. But I'm not a mechanic so only guessing. What do you think?

The most stressful thing you can possibly do to a motor is spin it faster; inertial loads on your rods and bearings are exponentially related to engine RPM so you can break things very quickly when tempering with the rev limit. Seeing as camshafts make more power by moving the torque peak further up into the RPM range, a heads/cam engine can be highly stressed if you drive it at high RPMs or try to raise the rev limit to make use of that high end power.
Large camshafts are also very hard on the valvetrain. There are PLENTY of examples of bent pushrods, broken timingchains, broken springs, broken retainers, etc. The timing chain is particularly problematic on these cars when you try and put a big cam with heavy springs. When the chain breaks, the pistons impact the vaves and the engine can be completely destroyed.

With superchargers, on the other hand, you have a higher chance of detonation occuring, and a good knock event can break the pistons, again causing extensive damage. This can happen very quickly; I know of two supercharged cars that blew up right on the dyno before they ever saw the road. I also know of some going over 100K miles. Most of it is in the tune.

I think the real answer to your question is that it all depends on how much power you are trying to make, how it gets tuned, and how it gets driven. The bottom line is that making more power demands more from the engine; no way around that... A 540RWHP supercharged LS2 engine that is tuned very conservatively is probably going to be more durable than the same engine as a maximum effort high reving cammed beast. Now try to make 700WHP from the same engine with boost and things change.

Of course, supercharging allows more power and more torque to be made with none of the driveability issues that come with big cams, so for me its always been a no brainer which one I'd pick ;)

i have to vote supercharger,, i ve seen them blow off a motor at the drags don t remember seeing a camshaft fly out

i have to vote supercharger,, i ve seen them blow off a motor at the drags don t remember seeing a camshaft fly out

In that case you should remove your intake manifold as well. I've seen intake manifolds blow off cars too, if that is the golden standard by which we measure engine stress ;)... I don't remember seeing a turbo fly out of an engine, maybe turbos are safer because of that? :lol:

You probably don't realize that those drag cars are carburatted and the reason the supercharger blows off is because when they backfire the space between the supercharger and the engine is full of air and fuel, which burns and blows the supercharger off. This is no different than a normal backfire except when the blower is sitting there it has to come off. Most of the time there is no engine damage associated with that.

and so when it explodes theres no stess at all? superchargers make power but if the boost is all the time its stress i have a t-bird SC its supercharged from the factory but it only boosts on demand much less stress on motor its lasted 159,000 miles boost all the time is much different you still have the increased force on rod and main bearings all the time unless you think that increased combustion pressure has absolutely no effect on bearings and if that were true why bother using forged cranks and pistons wouldn t an old cast type be sufficient?

and so when it explodes theres no stess at all?

Actually, no. The explosion you are talking about is a backfire which means that the fuel is burning OUTSIDE of the engine, where it can't do anything to its rods or pistons ;) I know it might look mean and scary when you have no idea what is happening, but in reality backfires are a common problem with carburatted engines and one of the MANY reasons why you don't see modern cars running wet intake manifolds today :lol:

superchargers make power but if the boost is all the time its stress i have a t-bird SC its supercharged from the factory but it only boosts on demand much less stress on motor its lasted 159,000 miles boost all the time is much different you still have the increased force on rod and main bearings all the time

You really should try and learn a little bit more about superchargers before making these blanket comments. Every single supercharger kit on the market today has a bypass valve which is vacuum operated and therefore always open during idle and part throttle cruise. This is no different from a factory supercharger vehicle; all the boost is vented untill you go deep into the throttle, then the bypass valve closes and the engine goes into boost progressively. This is how supercharged Corvettes are able to retain near stock fuel economy.

unless you think that increased combustion pressure has absolutely no effect on bearings and if that were true why bother using forged cranks and pistons wouldn t an old cast type be sufficient?

It "be" sufficient up to a certain power level. Because the average increase in combustion pressure is not that great the factory components are reliable at modest power increases for many tens of thousands of miles. The vast majority of supercharged cars runs on completely stock internals, and all the offerings from names such as Lingenfelter and Callaway do so under warranties too. It is only when you try and go for very large power numbers that you begin to need the strength of forged components.

Actually, no. The explosion you are talking about is a backfire which means that the fuel is burning OUTSIDE of the engine, where it can't do anything to its rods or pistons ;) I know it might look mean and scary when you have no idea what is happening, but in reality backfires are a common problem with carburatted engines and one of the MANY reasons why you don't see modern cars running wet intake manifolds today :lol:



You really should try and learn a little bit more about superchargers before making these blanket comments. Every single supercharger kit on the market today has a bypass valve which is vacuum operated and therefore always open during idle and part throttle cruise. This is no different from a factory supercharger vehicle; all the boost is vented untill you go deep into the throttle, then the bypass valve closes and the engine goes into boost progressively. This is how supercharged Corvettes are able to retain near stock fuel economy.



It "be" sufficient up to a certain power level. Because the average increase in combustion pressure is not that great the factory components are reliable at modest power increases for many tens of thousands of miles. The vast majority of supercharged cars runs on completely stock internals, and all the offerings from names such as Lingenfelter and Callaway do so under warranties too. It is only when you try and go for very large power numbers that you begin to need the strength of forged components.
i m sorry was the question which is more stress big cams or LIMITED BOOST SOMETIME USED MODEST PRESSURE SUPERCHARGERS? did i not just see your motor all over the floor of your garage because your supercharged motor destroyed a piston? but i bet your cam was still good and no one with any experience would use a cast crank or piston with 11 pounds boost as you say you run which apparently was too much for your motor even in part time use and you say i should learn a little more about it my 500hp non-supercharged big cam motor runs just great hows yours running today?

I see more S/C cars grenade than H&C but it is a fallacy to compare them. First, it's pretty rare that a S/C stays below 500 HP, whereas it takes a max effort H&C (LS2 & LS3) to get above 500 rwhp. So you rarely see a S/C car that is comparable HP wise with your average H&C car. So HP wise, they aren't very comparable.

PL is right that rpm is major stress, but most mild H&C set-ups stay within a few hundred rpm of factory redline on LS2 & LS3 set-ups. Those that build for 500+ rpm higher shifts (e.g. 7000 or higher) start to see the impact of higher rpm and more issues with oiling and spun bearings. At least with the A4 transmission, rpm was proven to be a killer more often than a moderate HP increase.

Awesome information guys :coffeetime:

i m sorry was the question which is more stress big cams or LIMITED BOOST SOMETIME USED MODEST PRESSURE SUPERCHARGERS? did i not just see your motor all over the floor of your garage because your supercharged motor destroyed a piston? but i bet your cam was still good and no one with any experience would use a cast crank or piston with 11 pounds boost as you say you run which apparently was too much for your motor even in part time use and you say i should learn a little more about it my 500hp non-supercharged big cam motor runs just great hows yours running today?

How many miles on your motor? Is it over 65,000 yet?
Has it ever gone 203Miles an hour?
Do you take it to the track a couple of times a month?
Ever been on a roadcourse?
Do you redline it on a regular basis?

I'll bet you any money I could take your car, or any other modified car, on a road course and blow the engine within 30 minutes of hot lapping. ANYTHING breaks when you drive it hard enough; youtube "Corvette Z06 Blows Engine" and you will see even a bone stock, waranteed low mileage Corvette will blow when abused.

Now, to illustrate the complete pointlessness of your comparison:

"2008 Corvette Timing Chain Broke (http://forums.corvetteforum.com/c6-tech-performance/2205820-2008-ls3-timing-chain-failure.html)"
From that tread:
"This setup has had exactly 8k miles on it with mostly highway miles and the car has never been road raced. "
"Blown Timing Chain, UGH (This setup has had exactly 8k miles on it with mostly highway miles and the car has never been road raced.)"
From that tread:
"I have an '04 Goat with 55,000miles. have 400rwhp. It was my daily driver..ha

I broke my timing chain. I was in 3rd gear at about 80% throttle...going up a hill."

Sounds to me like big cam motors are a lot more fragile, while making a LOT less power :lol: ;)

In reality, ONCE AGAIN, NOW FOR THE 3RD TIME... It all depends on how it is put together, how much power it makes and how it gets tuned.
If you want more examples of heads and cam car failures just let me know ;) I see about one every other month on other forums :thumbsup3:

How many miles on your motor? Is it over 65,000 yet?
Has it ever gone 203Miles an hour?
Do you take it to the track a couple of times a month?
Ever been on a roadcourse?
Do you redline it on a regular basis?

I'll bet you any money I could take your car, or any other modified car, on a road course and blow the engine within 30 minutes of hot lapping. ANYTHING breaks when you drive it hard enough; youtube "Corvette Z06 Blows Engine" and you will see even a bone stock, waranteed low mileage Corvette will blow when abused.

Now, to illustrate the complete pointlessness of your comparison:

"2008 Corvette Timing Chain Broke (http://forums.corvetteforum.com/c6-tech-performance/2205820-2008-ls3-timing-chain-failure.html)"
From that tread:
"This setup has had exactly 8k miles on it with mostly highway miles and the car has never been road raced. "
"Blown Timing Chain, UGH (This setup has had exactly 8k miles on it with mostly highway miles and the car has never been road raced.)"
From that tread:
"I have an '04 Goat with 55,000miles. have 400rwhp. It was my daily driver..ha

I broke my timing chain. I was in 3rd gear at about 80% throttle...going up a hill."

Sounds to me like big cam motors are a lot more fragile, while making a LOT less power :lol: ;)

In reality, ONCE AGAIN, NOW FOR THE 3RD TIME... It all depends on how it is put together, how much power it makes and how it gets tuned.
If you want more examples of heads and cam car failures just let me know ;) I see about one every other month on other forums :thumbsup3:
the question was not if motor has 65,000 mi or it goes on a road race track or if it belonged to the amazing powerlab .! I maintain 2 new stock motors 1 modified w/ supercharger ,other big cam, heads the supercharged motor has more stress on bottom end and will fail first ! again my motor is still running how about yours? and the only thing pointless is having a dicussion with someone who thinks they know everything about everything but yet isn t sure if they are going to rebuild their busted motor themselves. how could you possibly expect any shop to know anywhere near what you think you know? Your argument might be slightly more convincing if we all had not seen the pictures or your blown piston and motor all over your floor. and i ve had several N/A big cam motors w/ 450-550hp go 100,000mi and do you think you re the only one who runs them hard? i twist mine up 6500rpm regulaly

the question was not if motor has 65,000 mi or it goes on a road race track or if it belonged to the amazing powerlab .! I maintain 2 new stock motors 1 modified w/ supercharger ,other big cam, heads the supercharged motor has more stress on bottom end and will fail first ! again my motor is still running how about yours? and the only thing pointless is having a dicussion with someone who thinks they know everything about everything but yet isn t sure if they are going to rebuild their busted motor themselves. how could you possibly expect any shop to know anywhere near what you think you know? Your argument might be slightly more convincing if we all had not seen the pictures or your blown piston and motor all over your floor. and i ve had several N/A big cam motors w/ 450-550hp go 100,000mi and do you think you re the only one who runs them hard? i twist mine up 6500rpm regulaly

Talking to you, is like talking to a child. Look at your argument for a second: If we had this discussion 3 weeks ago, when my car had 65,000 miles on a supercharged motor that was making 600rear wheel horsepower without as much as throwing a check engine light, would that mean that supercharged engines can't and don't ever break?
If I was any one of several people who have had a timing chain snap or a pushrod bend because of the added stresses posed by a big camshaft, would you still be having this argument with me?
In your mind, you have already answered your question; your big cam motor making mediocre power is the be-all, end-all off to making horsepower. In reality big cams are the most ghetto way possible to make power. When GM Engineers are designing a new engine, do you think they sit around and say: "Gee billybob, what is the biggest darn camshaft we can put on that engine? Lets make it surge and lope and buck and blow raw fuel out of the exhaust, it will sound sweet, just like one of them muscle cars from back in the day". No, they add displacement (Z06), or they add forced induction (ZR1), because that is how reliable horsepower is made while retaining driveability, fuel economy, and street manners.
I already answered your question: The answer is that it depends. At the same power level a supercharged engine will be MUCH less likely to experience any valvetrain failures, as you up the power level an agressive tune or a bad tank of gas can take out factory pistons on an aftermarket FI application. That is the FOURTH time I said this, but you are not listening because, again, in your mind you already have the answer.
And since you care so much about my engine; the rebuild is already paid for, I am having Late Model Engines rebuild it for me. The question on rebuilding has nothing to do with how much I know but rather on how much time I want to spend on it and wether I wanted to buy all the tools. Since I am spending the next month in Australia I decided I won't have the time to do it myself.

Talking to you, is like talking to a child. Look at your argument for a second: If we had this discussion 3 weeks ago, when my car had 65,000 miles on a supercharged motor that was making 600rear wheel horsepower without as much as throwing a check engine light, would that mean that supercharged engines can't and don't ever break?
If I was any one of several people who have had a timing chain snap or a pushrod bend because of the added stresses posed by a big camshaft, would you still be having this argument with me?
In your mind, you have already answered your question; your big cam motor making mediocre power is the be-all, end-all off to making horsepower. In reality big cams are the most ghetto way possible to make power. When GM Engineers are designing a new engine, do you think they sit around and say: "Gee billybob, what is the biggest darn camshaft we can put on that engine? Lets make it surge and lope and buck and blow raw fuel out of the exhaust, it will sound sweet, just like one of them muscle cars from back in the day". No, they add displacement (Z06), or they add forced induction (ZR1), because that is how reliable horsepower is made while retaining driveability, fuel economy, and street manners.
I already answered your question: The answer is that it depends. At the same power level a supercharged engine will be MUCH less likely to experience any valvetrain failures, as you up the power level an agressive tune or a bad tank of gas can take out factory pistons on an aftermarket FI application. That is the FOURTH time I said this, but you are not listening because, again, in your mind you already have the answer.
And since you care so much about my engine; the rebuild is already paid for, I am having Late Model Engines rebuild it for me. The question on rebuilding has nothing to do with how much I know but rather on how much time I want to spend on it and wether I wanted to buy all the tools. Since I am spending the next month in Australia I decided I won't have the time to do it myself.
like i said IF YOU ARE SUCH AN EXPERT AT THIS WHY IS LATE MODEL ENGINES FIXING YOUR MISTAKE? and the "i m going out of town" excuse please! lets just agree to disagree and let it go cause you are right about one thing YOU WILL NEVER CONVINCE ME THAT YOU HAVE A CLUE

like i said IF YOU ARE SUCH AN EXPERT AT THIS WHY IS LATE MODEL ENGINES FIXING YOUR MISTAKE? and the "i m going out of town" excuse please! lets just agree to disagree and let it go cause you are right about one thing YOU WILL NEVER CONVINCE ME THAT YOU HAVE A CLUE

You don't have to be convinced that I have a clue. I have a Mechanical Engineering degree and work on an Engine research lab; the only person that really needs to be convinced that I have a clue on Engines is my employer ;)..
But that's not why I replied. I was going to let this one go but I just had to:

"Why is late model engines fixing my mistake"?
Blowing my engine up was not a mistake; it is just what happens when you drive something hard enough for long enough. If you've never broken a car then you either drive like my grandmother, or you don't put on enough miles. If you don't believe me, you can take me up on my bet: YOUR car, 20 minutes on a roadcourse, and me driving. I will not bounce the rev limiter, hit anything, slam gears, or dump the clutch. And I bet you $1000 that before 20 minutes is up, something breaks.
Check this out: 2008 Corvette Z06, bone stock, low miles. It broke a piston. Didn't even need boost or impressive power numbers :lol: :
ZLT7DjnKvnY

Its just how it goes. And yes, I'm out of town ;) Sidney and Melbourne untill Jan 7th. Didn't really think I could fly there with the motor and try to rebuild it while on vacation :lol:

You don't have to be convinced that I have a clue. I have a Mechanical Engineering degree and work on an Engine research lab; the only person that really needs to be convinced that I have a clue on Engines is my employer ;)..
But that's not why I replied. I was going to let this one go but I just had to:

"Why is late model engines fixing my mistake"?
Blowing my engine up was not a mistake; it is just what happens when you drive something hard enough for long enough. If you've never broken a car then you either drive like my grandmother, or you don't put on enough miles. If you don't believe me, you can take me up on my bet: YOUR car, 20 minutes on a roadcourse, and me driving. I will not bounce the rev limiter, hit anything, slam gears, or dump the clutch. And I bet you $1000 that before 20 minutes is up, something breaks.
Check this out: 2008 Corvette Z06, bone stock, low miles. It broke a piston. Didn't even need boost or impressive power numbers :lol: :
ZLT7DjnKvnY

Its just how it goes. And yes, I'm out of town ;) Sidney and Melbourne untill Jan 7th. Didn't really think I could fly there with the motor and try to rebuild it while on vacation :lol:

:thumbsup::thumbsup: Nice!!