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I do that sort of stuff all day - every day to earn a living.
I swap my Cvt to a manual transmission
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I totally forgot I was arguing with an engineer...
As much as I hate bringing math into any situation, math is hard to beat with a hammer... On top of that, I should have remembered that it's typical to design a component to take twice the beating you expect it to.
I'll concede the point that that 3k is about where the engine should live for minimal stress on internal components, but I still say that even around an average RPM of 4k or a bit higher won't significantly impede engine life.
Thanks for breaking it down.
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Yes - you hit the nail on the head with the word stress.
Almost everywhere speed and mass are involved there is also an exponent involved, so slight changes in either will cause huge increases in forces acting on the parts.
Almost all overspeed failures (throwing a rod or the like) are due to too much force acting on a part.
Operating at very high RPM's over long periods of time tends to cause the parts to weaken or distort. Under these conditions, it is impossible to predict exactly how long an engine will last, but sudden failure could happen at any time.
Operating in the "safe range" keeps forces acting on the parts well below their strength limits, so sudden failure is not very likely.
Wear is typically not a factor. As you said and most of us know, today's engine parts are machined to near-perfect tolerances, and today's oils are infinitely better than they were even a few years ago.
One other thing I do wonder about, is the cooling system.
On a test stand in a lab, the engine can get supplied with however much coolant it needs to run at full power and stay at the correct operating temperature.
In a car, I don't know if the cooling system can transfer and dissipate all the heat the engine makes when it is running under a full power, full load condition.
Almost everywhere speed and mass are involved there is also an exponent involved, so slight changes in either will cause huge increases in forces acting on the parts.
Almost all overspeed failures (throwing a rod or the like) are due to too much force acting on a part.
Operating at very high RPM's over long periods of time tends to cause the parts to weaken or distort. Under these conditions, it is impossible to predict exactly how long an engine will last, but sudden failure could happen at any time.
Operating in the "safe range" keeps forces acting on the parts well below their strength limits, so sudden failure is not very likely.
Wear is typically not a factor. As you said and most of us know, today's engine parts are machined to near-perfect tolerances, and today's oils are infinitely better than they were even a few years ago.
One other thing I do wonder about, is the cooling system.
On a test stand in a lab, the engine can get supplied with however much coolant it needs to run at full power and stay at the correct operating temperature.
In a car, I don't know if the cooling system can transfer and dissipate all the heat the engine makes when it is running under a full power, full load condition.
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In general, I'd assume lab tests run a far more efficient cooling system. Think about it, changes in air temperature not only affect the airs ability to disapate heat, but the change in air density also matters. Air density also comes into play when you deal with altitude etc. Even the little insignificant things, like bugs and rocks getting into the radiator fins can make a difference in cooling efficiency over 30,000 miles. A/C systems also make a huge difference. Not only does the engine get loaded by the compressor, but the A/C condenser gets first dibs on fresh air.
99% of the engines I've seen on test rigs have NEVER had an A/C condenser on front of them.
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Well played Aleks!!....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
That's where I'm from!! Good ol Pocono Mountain. You familiar with Brodheadsville at all? My step-mom's family are the Kinsley's and own the grocery store there. I was there a couple of weeks ago when I had just gotten my Caliber and learned quickly about which gear has best ratio/power lol. And learned how to heel/toe shift better because we're known of our curvy roads up there.
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Hi Cheekyboy21,
Cheers! I was interested in your project, I don't know if it's too late to ask, but could you show us how you did it and what parts did you buy to do it? I have the same thing in mind but I don't really know where to start. It would be very helpful if you can reply to this message with everything you need and the process. Thank you very much!
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