A Simple Auto Engine Conversion

"Ernest Christley" wrote in message
...

http://www.rotaryaviation.com/PSRU Zen Part 2.html

Bad link.

Zebulon wrote:
"Ernest Christley" wrote in message
...
http://www.rotaryaviation.com/PSRU Zen Part 2.html

Bad link.




The link is correct, you just have to use the whole thing.

http://www.rotaryaviation.com/PSRU Zen Part 2.html


Charles

"Zebulon" @###@.^net wrote in message
...

"Ernest Christley" wrote in message
...

http://www.rotaryaviation.com/PSRU Zen Part 2.html

Bad link.




Ok, got it now, but what's your point?

Is this what you are referring to?

"At this point it should be obvious that our original assumption about the
intended purpose of the damper is wrong. The engineers in Detroit are not
stupid and they don’t put in relatively expensive parts for no reason, so
why do manual transmission equipped cars have a damper? The main reason is
to absorb unexpected torque overloads. This happens only on rare occasions
like when someone gets overly aggressive with the throttle and suddenly
releases the clutch. The springs store the energy of the shock load and
release it in a more controlled fashion in order to avoid breaking
drive-train parts. "

"Zebulon" @###@.^net wrote in message
...

"Zebulon" @###@.^net wrote in message
...

"Ernest Christley" wrote in message
...

http://www.rotaryaviation.com/PSRU Zen Part 2.html

Bad link.




Ok, got it now, but what's your point?

Is this what you are referring to?

"At this point it should be obvious that our original assumption about the
intended purpose of the damper is wrong. The engineers in Detroit are not
stupid and they don't put in relatively expensive parts for no reason, so
why do manual transmission equipped cars have a damper? The main reason
is to absorb unexpected torque overloads. This happens only on rare
occasions like when someone gets overly aggressive with the throttle and
suddenly releases the clutch. The springs store the energy of the shock
load and release it in a more controlled fashion in order to avoid
breaking drive-train parts. "



The damper, which is indeed a relatively expensive part, is on the other end
of the engine and is intended to eliminate resonance within the engine. A
breif treatise, which probably started as an an internal document at one of
the big three auto makers, has been included on this forum a number of times
and is probably in an issue of Contact! Magazine as well; but I can't find a
copy on my current computer.

I could easily be incorrect about the purpose of the springs, but another
article from Contact! regarding the development of the BD-5 drive train
(which I also can not find) does provide some food for thought.

Peter

"Peter Dohm" wrote in message
. ..

The damper, which is indeed a relatively expensive part, is on the other
end of the engine and is intended to eliminate resonance within the
engine. A breif treatise, which probably started as an an internal
document at one of the big three auto makers, has been included on this
forum a number of times and is probably in an issue of Contact! Magazine
as well; but I can't find a copy on my current computer.

I could easily be incorrect about the purpose of the springs, but another
article from Contact! regarding the development of the BD-5 drive train
(which I also can not find) does provide some food for thought.


I have seen the BD-5 article, and agree totally with it, and the article
referenced above. My only doubt is Detroit's intent when originally
implementing these spring mechanisms.

Years ago during my auto racing days, a custom clutch builder related to me,
that the springs served only to reduce or eliminate chatter during
engagement, and assist the smooth engagement of the clutch. Although I
didn't understand exactly how, especially at that time, I now suspect his
has a lot to do with resonance.

If the mechanisms were implemented to dampen shock loads during aggressive
driving, why would so many high performance clutch assemblies omit them?
They all seem to prefer solid clutch disks because these mechanisms are
prone to failure, especially in activities like drag racing.

Has anyone published actual tested results on the amount of torque required
to flex these mechanisms? Whatever it is, I would guess they would offer
little resistance to a V-8 crankshaft and steel flywheel assembly spinning
5000 to 8000 RPM, when someone dumps a clutch. I always assumed that's why
most of them have springs with a flat profile wire. It looks to me like the
springs are designed to be bottomed out regularly.

Zebulon wrote:

Has anyone published actual tested results on the amount of torque required
to flex these mechanisms? Whatever it is, I would guess they would offer
little resistance to a V-8 crankshaft and steel flywheel assembly spinning
5000 to 8000 RPM, when someone dumps a clutch. I always assumed that's why
most of them have springs with a flat profile wire. It looks to me like the
springs are designed to be bottomed out regularly.



If you read the engineering texts you will find they are for reducing
shock loads and prevent gear chatter when idling or loafing around in
third gear on surface streets. Dan Horton who used to post hear did
measure them, though did not publish all of his data. They bottom out
well before the torque the engine is able to produce is reached, as you
would expect. In fact, I believe this is necessary to avoid a
longitudinal resonance during aggressive throttle changes.

Charles

On Sep 3, 11:03*am, Charles Vincent wrote:
Zebulon wrote:

Has anyone published actual tested results on the amount of torque required
to flex these mechanisms? Whatever it is, I would guess they would offer
little resistance to a V-8 crankshaft and steel flywheel assembly spinning
5000 to 8000 RPM, when someone dumps a clutch. I always assumed that's why
most of them have springs with a flat profile wire. It looks to me like the
springs are designed to be bottomed out regularly.

If you read the engineering texts you will find they are for reducing
shock loads and prevent gear chatter when idling or loafing around in
third gear on surface streets. *Dan Horton who used to post hear did
measure them, though did not publish all of his data. *They bottom out
well before the torque the engine is able to produce is reached, as you
would expect. *In fact, I believe this is necessary to avoid a
longitudinal resonance during aggressive throttle changes.

Charles

The reciprocating engine has power pulses, which the flywheel
is expected to damp out. That flywheel can't damp it all out, of
course, and so those springs will allow a bit of flex to minimize the
pulsations being transmitted to the drive train. In racing, component
life and smoothness are not prime concerns; strength and minimal
failure points are, so they're left out.

Dan

"Peter Dohm" wrote

The damper, which is indeed a relatively expensive part, is on the other
end of the engine and is intended to eliminate resonance within the
engine. A breif treatise, which probably started as an an internal
document at one of the big three auto makers, has been included on this
forum a number of times and is probably in an issue of Contact! Magazine
as well; but I can't find a copy on my current computer.

I could easily be incorrect about the purpose of the springs, but another
article from Contact! regarding the development of the BD-5 drive train
(which I also can not find) does provide some food for thought.

You are thinking of two different things.

The thing on the accessory end of the engine is the harmonic balancer, and
it does indeed dampen resonance in the crankshaft.

Dampeners also exist that go between the engine and the load, usually found
in industrial applications, or in marine applications.
--
Jim in NC

"Morgans" wrote in message
...

"Peter Dohm" wrote

The damper, which is indeed a relatively expensive part, is on the other
end of the engine and is intended to eliminate resonance within the
engine. A breif treatise, which probably started as an an internal
document at one of the big three auto makers, has been included on this
forum a number of times and is probably in an issue of Contact! Magazine
as well; but I can't find a copy on my current computer.

I could easily be incorrect about the purpose of the springs, but another
article from Contact! regarding the development of the BD-5 drive train
(which I also can not find) does provide some food for thought.

You are thinking of two different things.

The thing on the accessory end of the engine is the harmonic balancer, and
it does indeed dampen resonance in the crankshaft.

Dampeners also exist that go between the engine and the load, usually
found in industrial applications, or in marine applications.
--
Jim in NC

Very true, I had momentarily forgotten those. They would require some
mathematical analysis to specify correctly and I believe that Molt Taylor
may have used something of the sort on the IMP or Mini IMP. There are also
some so-called "dry fluid couplings" that I sort of understand, but not
completely.

Peter

Peter Dohm wrote:

"Morgans" wrote in message
...

"Peter Dohm" wrote


The damper, which is indeed a relatively expensive part, is on the other
end of the engine and is intended to eliminate resonance within the
engine. A breif treatise, which probably started as an an internal
document at one of the big three auto makers, has been included on this
forum a number of times and is probably in an issue of Contact! Magazine
as well; but I can't find a copy on my current computer.

I could easily be incorrect about the purpose of the springs, but another
article from Contact! regarding the development of the BD-5 drive train
(which I also can not find) does provide some food for thought.

You are thinking of two different things.

The thing on the accessory end of the engine is the harmonic balancer, and
it does indeed dampen resonance in the crankshaft.

Dampeners also exist that go between the engine and the load, usually
found in industrial applications, or in marine applications.
--
Jim in NC


Very true, I had momentarily forgotten those. They would require some
mathematical analysis to specify correctly and I believe that Molt Taylor
may have used something of the sort on the IMP or Mini IMP. There are also
some so-called "dry fluid couplings" that I sort of understand, but not
completely.

Peter




A coupling consisting of a pair of "wavy" plates and a dry fluid (like
bird shot) that does the actual connecting.

IIRC, it was adapted from an early automotive "automatic clutch" ??

--

Richard

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