Could somebody explain me, what the whole "camming" the exhaust or engine is? (For example: Corvettes) Why is it making the car sound like a 2 stroke engine?

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littledevil3

sounds like a rotary

07/19/2015 - 13:57 |
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Anonymous

In simplest terms, bigger cams have larger intake and exhaust lobes than stock = intake and exhaust valves open longer = more airflow in and more exhaust gas out. They’re esp. effective at higher RPMs because the gasses have more velocity behind them, and you can obviously burn more fuel and make more power. However, it comes at the cost of lower end torque, because the gasses in the system do not have as much velocity. The longer duration openings and larger separation of the lobes gives you that "lopey" sound at idle.

I have a more mild cam in my car, but it makes the power band so incredibly smooth and raised my redline by about 700 rpms with stock valve springs. And when it lopes hard, the whole car shakes :) nothing quite like it, completely changed the way the car drives

https://www.youtube.com/watch?v=5kmMdn8A8EA))

07/19/2015 - 14:03 |
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Beneto

In reply to by Anonymous (not verified)

Thanks!

07/19/2015 - 17:54 |
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Samniss Arandeen

"Camming", or replacement of the engine’s camshaft(s), helps the engine make more power by altering valve lift, timing, and duration. Certain camshaft profiles help the engine breathe better at certain RPM ranges, usually up high in the case of a performance cam. However, there is a tradeoff: at lower RPM such as at idle, the camshaft’s altered characteristics actually impede the engine’s ability to intake and exhaust efficiently. In the case of the LS series engine, the crossplane V8 sends uneven exhaust pulses, thus the characteristic sound. It’s magnified by the low-RPM breathing inefficiencies of the camshaft, resulting in the sound you compared to a two-stroke.

Long story short, the engine sounds like it does at idle because the owner has prioritized high-RPM efficiency and throttle response.

07/19/2015 - 14:06 |
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The high RPM efficiency really helps to smooth the power bands of the V8 cars out. My torque band before cams looked like a "n". Now, once I hit peak torque, it stays there until I redline. Dramatic difference

Also, a cam with a large lobe separation angle primes the car for a supercharger/nitrous/turbocharger. Many of the supercharged Mustangs out there pick up well over 80 horsepower with a camshaft change alone.

07/19/2015 - 14:14 |
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Thanks for explaining this! :)

07/19/2015 - 15:23 |
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