Shane,
I loved the answers, but thought I'd throw some more haze in the way
In my mind electronic ignition was developed first to get a hotter spark.
My dad put together one back in '67 or '68 for our Plymouth. He found one
problem in the spark coil though, the fire was so "hot" it would arc over
the top of the spark coil. Now days, driven by the left coast again,
emission requirements are so tight that pulse to pulse timing is a major
factor in controlling what comes out the tail pipe. This, of course, has
no relation to any increase/decrease of power out of the engine.
I personally don't think the manufacturers ever thought about costs (or is
it profits) Again thoughts go to Plymouth and my starter solenoid. It
broke one night and having a lathe we thought about building a new
contact. Got the thing apart and found it had a 5/16-18 stud attached to
a penny sized puck that in turn overlapped 1/16" with the other side of
the switch. Planned breakage at it's best!!
The air pump was put on to take out unburned hydrocarbons in the exhaust
stream. The concept was VERY hot, low oxygen exhaust exposed to a "oxygen
rich" external air flow would self-ignite and result in more complete
combustion. Then they started to think about Nitrogen-Oxides and
everything changed again. This was before the Catalytic Converter era.
If a car has a 5 speed gearbox isn't it a "real 5 speed"??? I think it's
more important to look at what is the ultimate performance target for the
car, also what can the power plant handle. A 12 cylinder engine with
smaller displacement/cylinder can turn higher sustained revs and has
different power bands (see I do read your stuff Shane) than a 6 cylinder
large displacement/cylinder engine. My thoughts here turn to my old Vol.
Fire Department and our number 2 Engine. Came out of Pennsylvania with a
870 cube straight 6. Top speed 55 but it would carry it's 35000 pounds
straight up at that speed.
I liked the math on the tire size, but one thing I found out when putting
the new tires on mine. I got a "old guy" at the shop. He'd actually sold
tires to TR6 customers when the cars were new. He went through all of the
tires they had in 215/70-15 to come up with one that had the correct
outside diameter he thought it should have. Did a good job though
according to the GPS my speed is only +/- 0.2 mph
This really is the FUN part of the list, hope everyone had a Happy
Thanksgiving
Steve
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net]On
Behalf Of Shane Ingate
Sent: Monday, December 02, 2002 7:24 AM
To: 6 Pack
Cc: jswarth1@tampabay.rr.com
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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