[Shotimes] M3 vs. GSX part 2 (long)

[Robert Bruce]

I used to race a dirt late model stock with a 250 cu in Chevy 6.  It had
14.5:1 compression, Crower cam, 390 carb(rules limit), extensively ported
head & ran lots of methanol.  Plenty of power for a 2450 lb car.  By no
means was it smooth running.  Would hardly even idle below 1000 rpm.
Biggest problem was the length of the crankshaft.  Over a season of racing,
the crank would eventually develop a twist.  This would throw the timing off
for the rear most cylinders.  :-(

Oh yea, also ..... the distributor had a 2 piece shaft that also drives the
oil pump.  Had problems breaking oil pump drives.
http://www.performancedistributors.com/ cured our problem with a custom one
piece distributor / oil pump driveshaft.

Robert Bruce
93 atx


-----Original Message-----
From: shotimes-admin@autox.team.net
[mailto:shotimes-admin@autox.team.net]On Behalf Of Marc Randolph
Sent: Monday, May 12, 2003 5:34 PM
To: shotimes@autox.team.net
Subject: Re: [Shotimes] M3 vs. GSX part 2 (long)


It's amazing, though, how much fun the straight 6 is when you put 10:1s in
it, an Offy intake, Clifford 3X3 headers, and a Holley 390. That '72
Chevelle was pretty fast.

Marc/Atl

----- Original Message -----
From: "Donald Mallinson" <dmall@mwonline.net>
To: <shotimes-admin@autox.team.net>
Cc: <shotimes@autox.team.net>
Sent: Saturday, May 10, 2003 9:32 AM
Subject: Re: [Shotimes] M3 vs. GSX part 2 (long)


> The old Chevy "Stovebolt" straight 6 was a super nice motor,
> just not very powerful.
>
> GM, in a moment of clear and innovative thought brought back
> the STovebolt with new features and that motor in my son's
> Trailblazer is a joy to listen to and drive.  Super smooth,
> lots of torque and in a first for factory GM straight six's,
> gobs of power.  This motor is a winner.
>
> Don Mallinson
>
> Ron Nottingham wrote:
> > 60-degree V6 - good balance, in phase (ex. Ford and GM 3.0L "small"
V6's)
> > 90-degree V6 - out of balance, out of phase (ex. Ford and GM 3.8L "big"
> > V6's)
> > 60-degree V8 - out of balance, out of phase (Ford SHO V8, Lotus V8)
> > 90-degree V8 - good balance, in phase (most all domestic small and big
block
> > V8's)
> >
> > I don't think the flat (horizontally opposed cylinders) engines are the
best
> > naturally balanced engines.  Ever drive most anything with an I6 or a
V12?
> > My vote goes to the V12, with the I6 a close 2nd.
> >
> > Ron N. - Dalton, GA
> > 90 SHO
> > 89 325i
> > 9? 750iL (driven more V12's lately than anything else :-)
> > "It takes a man to suffer ignorance and smile"
> >
> >
> > ----- Original Message -----
> > From: "Ron Childs" <rbchilds@pacbell.net>
> >
> >
> >>As I recall, Buick extended the life of their V6
> >>(which is today's GM 3800) by going to the "even fire"
> >>crankshaft. I think that many newer engines have
> >>offset cranks because of odd cylinder bank angles.
> >>
> >>As I had mentioned previously, the "even fire" cranks
> >>will make the engines smoother because the cylinders
> >>fire at even intervals but they will not help with the
> >>inherent imbalance cylinder bank angles mismatched
> >>with the number of cylinders. Balance shafts do.
> >>
> >>I think (somebody chime in if I am wrong) that
> >>horizontally opposed engines (Porsche, Subaru, etc.)
> >>are the best as far as natural balance.
> >>
> >>-Ron
> >>
> >>--- BJamesjr@aol.com wrote:
> >>
> >>>I spotted my 97 Helms manual on the bookshelf so I
> >>>did a bit of looking.  The
> >>>manual clearly shows offset crank journals on the V8
> >>>crankshaft.  I can't
> >>>tell if they offset them enough to even out the
> >>>firing pulses or not.  I
> >>>thought I remembered that GM offset the crank
> >>>journals on some of their 90
> >>>degree V6's to help with this.
> >>>
> >>>Also I found a diagram of the front of the engine
> >>>that would lead me to
> >>>believe that the balance shaft turns at crankshaft
> >>>speed.  The only diagrams
> >>>I can find that show part of the balance shaft
> >>>basically show a shaft with an
> >>>eccentric weight on it, sort of like a camshaft with
> >>>a single very long lobe
> >>>on it.
> >>
> > _______________________________________________
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> > Shotimes@autox.team.net
> > http://www.team.net/mailman/listinfo/shotimes
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