Rotary Engine Failure Discussion Discussion Of causes, diagnosis and prevention of engine failures

Strength Of Factory Blocks

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Old 10-17-2003, 09:57 AM
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Originally Posted by Travis R' date='Oct 16 2003, 10:27 AM
OK apparently there is a graph of what you are asking on page 454 of John Heywood's book "Internal Combustion Engine Fundamentals". We should have a copy of it at the shop. So I'll take a look tonight. They are probably for non-turbo piston engines though.
Yup... but still it will be helpfull to see...
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Old 10-17-2003, 10:23 AM
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Originally Posted by MaTT_FoULk' date='Oct 17 2003, 04:47 AM
That has what to do with the topic at hand?
i have an REW and solid bracing........the twisting breaks lots of expensive things. believe me i know!
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Old 10-17-2003, 11:22 AM
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Originally Posted by Travis R' date='Oct 17 2003, 04:56 AM
The book I mentioned wasn't down at the shop. Sorry I couldn't come up with numbers.

But a friend of mine brought up the point that there is only so much energy available because of the fuel. So assuming that you are getting a complete burn in your normal combustion cycle, the max chamber pressure should be the same as it is when it auto-ignites (detonation). The difference is that the auto-ignition will have a very rapid spike to that pressure, and the "normal" cycle will have a (relatively) longer build up to that pressure.

That's just talk though. Data from the book could tell us something else.
I agree, but from what I understand these large 'spikes' of pressures are caused when the rotating assembly of the engine has force against it, attempting to stop it and twist it backwards (yes, in the opposite direction). It makes sense if you consider very hard pre-ignitive knock that creates combustion, then a flamefront, and then torque on the opposite side of the rotor face that'll try and push it backwards.



B
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Old 10-17-2003, 11:23 AM
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Originally Posted by MaTT_FoULk' date='Oct 17 2003, 12:47 AM
That has what to do with the topic at hand?
He's just being Vosko, Matt.
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Old 10-17-2003, 11:25 AM
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Originally Posted by Hassan' date='Oct 17 2003, 06:56 AM
[quote name='j9fd3s' date='Oct 16 2003, 10:11 AM'] ah ok, so you know how fc's always have 1 borken engine mount? and its always the same one? i think when you drop the clutch it tries to twist the motor, too much twist = broken rear plate.



mike
Hmm... that is interesting.



Well we are now using solid motor mounts on our cars (Mine and 87GTRs) [/quote]

Same with me and mine never broke, either. Interesting. Maybe there's something involving torsional vibration here or some other field of physics that's well above my pay grade.



On another note, I believe one reason why the passenger side mount disintegrates and breaks is because it's directly next to the turbocharger which radiates gobs and gobs of heat.



B
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Old 10-17-2003, 01:52 PM
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Originally Posted by Travis R' date='Oct 17 2003, 04:56 AM
The book I mentioned wasn't down at the shop. Sorry I couldn't come up with numbers.

But a friend of mine brought up the point that there is only so much energy available because of the fuel. So assuming that you are getting a complete burn in your normal combustion cycle, the max chamber pressure should be the same as it is when it auto-ignites (detonation). The difference is that the auto-ignition will have a very rapid spike to that pressure, and the "normal" cycle will have a (relatively) longer build up to that pressure.

That's just talk though. Data from the book could tell us something else.
its the shock wave thats the problem



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Old 10-17-2003, 02:05 PM
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Originally Posted by j9fd3s' date='Oct 17 2003, 10:52 AM
[quote name='Travis R' date='Oct 17 2003, 04:56 AM'] The book I mentioned wasn't down at the shop. Sorry I couldn't come up with numbers.

But a friend of mine brought up the point that there is only so much energy available because of the fuel. So assuming that you are getting a complete burn in your normal combustion cycle, the max chamber pressure should be the same as it is when it auto-ignites (detonation). The difference is that the auto-ignition will have a very rapid spike to that pressure, and the "normal" cycle will have a (relatively) longer build up to that pressure.

That's just talk though. Data from the book could tell us something else.
its the shock wave thats the problem



mike [/quote]

Shockwave?



B
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Old 10-17-2003, 02:19 PM
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Originally Posted by BDC' date='Oct 17 2003, 11:05 AM
[quote name='j9fd3s' date='Oct 17 2003, 10:52 AM'] [quote name='Travis R' date='Oct 17 2003, 04:56 AM'] The book I mentioned wasn't down at the shop. Sorry I couldn't come up with numbers.

But a friend of mine brought up the point that there is only so much energy available because of the fuel. So assuming that you are getting a complete burn in your normal combustion cycle, the max chamber pressure should be the same as it is when it auto-ignites (detonation). The difference is that the auto-ignition will have a very rapid spike to that pressure, and the "normal" cycle will have a (relatively) longer build up to that pressure.

That's just talk though. Data from the book could tell us something else.
its the shock wave thats the problem



mike [/quote]

Shockwave?



B [/quote]

yah its the difference between a controlled burn and and explosion



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Old 10-17-2003, 02:19 PM
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Flame front during detonation moves much faster than regular combustion, hence shock wave.



Combustion is a very fast burn VS detonation which is closer to an explosion. Like gunpower VS TNT.







EDIT: Mike types MaD QUick yO!
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Old 10-17-2003, 02:26 PM
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Oh, you mean kind of like what I said?
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