OK. Now you guys are REALLY scaring me.
----- Original Message -----
From: "Shane Ingate" <madmax_xx@hotmail.com>
To: "6 Pack" <6pack@autox.team.net>
Cc: <jswarth1@tampabay.rr.com>
Sent: Monday, December 02, 2002 11:24 AM
Subject: Answers to TR6 questions
> All,
>
> I'm such a sucker. If the Hare-Krishna stop me on the street, I will
always
> politely answer their questions. So now Jim Swarthout asks some
questions,
> so I'm going to have a bash at answering some of them. WARNING: I'm
> probably wrong on most of them, but would appreciate some kind souls to
set
> me right.
>
> > 1) There were 2 reasons why electronic ignition was developed? Both
> > answers pertain to the consumer, or auto owner.
> It is cheaper to manufacture, install and maintain. Car manufacturers
will
> bend over backwards to save 1 cent on an item. An added benefit is that
> distributor-shaft wobble is no longer a main issue.
>
> > 2) Upon introduction: Hydraulic Camshafts were touted to be a technology
> > breakthrough. Why? Was it really a ruse? Today many people believe that
> > hydraulic cams have a grind profile that is far superior to anything
> > that could be achieved in a mechanical cam. Is this True or False?
> Hydraulic cams were introduced because they did away with the valve
re-shim
> at 500 miles on every new car. I don9t really know the answer to this,
but
> I would guess False.
>
> > 3) What does an air pump, (smog pump), do? Explain the entire
> > cycle...peripheral equipment!
> Sorry, I ripped off all smog gear on my car. The air pump is a notorious
> consumer of hp!
>
> > 4) Why will roller rockers of an equal ratio open the valves further?
> I thought we covered this in a thread last week? And I'm not convinced
they
> do. (Nomex suit on!).
>
> > 5) What performance gains will you achieve by installing a long
> > duration...(extended period of valve opening)..., high lift, camshaft in
> > an otherwise stock engine?
> The gains will come at high-rpm, because more gas-air mixture can enter
the
> combustion chamber than with the stock cam. Air has mass, and it takes a
> finite duration to move it. The hi-po cam allows the valve to open wider
> and for a longer period of time, allowing this mass to slide on in.
>
> > 6) Why does an early Ferrari have a "true" 5-speed gearbox, but a 2003
> > Toyota does not?
> Why is an apple not an orange? Trick question? Ferraris built for
mountain
> passes, and Toys are built for freeway commuting?
>
> > 7) Suppose you have two 152ci TR engines side-by-side; same, make,
> > model. One engine has a compression ratio of 12:1 with a static
> > compression of 90. The other engine has a compression ratio of 7.5:1
> > with a static compression of 200. Which engine would you want in your
> > car? Why?
> Anyone on this list knows my love for power-bands and zero torque at low
> revs. The 12:1 motor of course!
>
> > 8) Is compression ratio related to static compression? Yes or No, and
> > why?
> Ooops. Better go back and read my books.
>
> > 9) You're speedometer shows 60MPH. You're Tachometer shows 3000 RPM's.
> > You're in 4th gear at 1:1 with a final drive ratio of 4:10. What is the
> > outside diameter of your tires?
> 27.56"? (I can only remember PI to 3 significant figures). If that9s the
> case, this is pretty close to a 215/70-15 tire.
>
> > 10) What are the differences between a machined part, a forging, and a
> > casting? Which is better? For what application? Be specific!
> I'll take the machined forged part, please. Forging aligns the crystals in
> the metal, for a much stronger part. But that does not mean it will fit
or
> look any better. Machining puts chunks of stuff on a lathe and turns
them
> for fit and finish. Sand casting can produce beautiful, but brittle
shapes.
>
> > 11) How are engine firing orders determined by the engineers? Is it
> > rhyme or reason?
> I always figured it was to minimize harmonics in the crankshaft, but I'll
> defer to the engineers. But this is a good question: why do BMW & Toy
> straight 6s have different firing orders? Length of crankshaft?
>
> > 12) If the piston to be fired is approaching compression...(15 degrees
> > BTDC)... and you have the timing set to fire at 10 degrees Before
> > TDC...why doesn't the piston travel back down...moving in the direction
> > from which it just came...?
> Ummm, inertia from all the rotating mass?
>
> Ok Folks, now tell me the real answers! A Man's got to know his limits!
>
> Shane Ingate in Maryland
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