porsches in my physics lecture, woo hoo

[Yargk]

Since I'm just starting college physics, most of the stuff isn't worth being awake for because it's so blatantly obvious. However, today in class I was given reason to pay attention. The professor was talking about torque and how on machinery things need to be torqued to specific values (duh!). The interesting part was the example... a transparency from a Porsche manual pertaining to the 4 cam carrera engines 1600 1600s and the spyder. A nice diagram was provided along with torque values for various things including the spark plugs. I found it kind of odd, and so did the professor that it was 25 foot pounds or 3.5 Kg/meters, which is confusing. Taken literary, the metric value is clearly wrong. It works out if you use 3.5 (KgX9.8(gravity))xmeters.

Keith
79 930

[Doug Zielke]

Ahhh...the 4-Cam.
The most beautiful motor Porsche ever made.



------------------
'81 SC Coupe (aka: "Blue Bomber")
Member: SCWDP
Canada West Region PCA
The Blue Bomber's Website
"If it ain't broke...we'll help you fix it 'til it is!"

[Jim Sims]

Sounds like the usual mixup between mass and force. Did the Prof. discuss the effect of fastener thread friction on the efficiency of torque conversion to fastener tension, i. e., using a dry fastener torque value on a lubricated fastener and thereby breaking it? The mkp (meter-kilopond) = 9.807 nt-m (newton-meters) torque unit in the older Porsche technical specification books is another interesting unit; it appears to be based on kilogram-meters since the conversion to newton-meters is basically the gravitational constant g.

[cim]

4cam... ...959 extension....3.5 (KgX9.8(gravity))xmeters.....yes...what do you think the scale does in the back (Nm)?

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www.angelfire.com/va3/vw

[Doug Zielke]

The "scale" provides a torque reading from the Schenck dynomometer the 4-cam is attached to.

------------------
'81 SC Coupe (aka: "Blue Bomber")
Member: SCWDP
Canada West Region PCA
The Blue Bomber's Website
"If it ain't broke...we'll help you fix it 'til it is!"

[trebor_911]

The vintage Schenck dyno measures in kp which is directly equal to kg ..
the formula for DIN horsepower is then ( force- kp x rpm) divided by 1000 = hp

[tazzieman]

Originally Posted by Doug Zielke

Ahhh...the 4-Cam.
The most beautiful motor Porsche ever made.

That's a lot of coils!

And now I get to drag this out again

[RWebb]

get him to talk about the center of gravity

[allaircooled]

This thread is almost 12 years old.

[James Brown]

Lets hope keith is now a engineer somewhere

[RWebb]

time for a re-visit with his prof.

[oscillon]

You're prof could be this guy...

This Porsche 912 Is A Classic AND It Will Baby

actually it's my car (and I'm a physics prof).

[redturbo911]

Wow almost 12 years.......

[Bob Kontak]

Originally Posted by oscillon

actually it's my car (and I'm a physics prof).

That's cool.

[Craig_D]

Originally Posted by oscillon

You're prof could be this guy...

This Porsche 912 Is A Classic AND It Will Baby

actually it's my car (and I'm a physics prof).

Way cool! Great looking car, and pretty neat that you got Jalopniked!

[RDM]

My high school physics teacher had a 912 from his time in the army. And now I... teach high school physical science to the kids of people in the military. Never underestimate the power of a teacher.

[Bob Kontak]

RDM - Love your 520.

They are so perfectly German looking (E28s)

[bfunke]

My high school physics teacher drove an old BMW Isetta - totally cool car.

[RDM]

Originally Posted by Bob Kontak

RDM - Love your 520.

They are so perfectly German looking (E28s)

Thanks! Theres's just something timelessly German about the cars from that age (as opposed to the hyperglandular BMWs, Mercedes, and even Porsches of today; all forced emotion on the surface, no class).

Mine was owned by a BMW salesman in a small town near here for 20+ years. When he died, it sat in the garage for a few years before his family sold it. The fabric seats, the color, the shape, the sweet nature of the drive; it's enrapturing. It is a real survivor, so it has all the charm intact. It's what I drive when the 911 is down (for an oxygen sensor or a voltage regulator or an alternator or an alternator again or the roads are salted- it's been a busy 4 months!). It's a nice choice to have, though I wish I didn't have to choose it quite so often....