[Spridgets] new bugeye motor

[corvallis at peoplepc.com]

Very good read; Mr. Computer's gonna save us all. ...bill in Oregon

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-----Original Message-----
From: spridgets-bounces at autox.team.net
[mailto:spridgets-bounces at autox.team.net] On Behalf Of Glen Byrns
Sent: Tuesday, May 26, 2009 2:41 PM
To: Spridgets
Subject: [Spridgets] new bugeye motor

On the way back from LotO last July, I felt something ws wrong with Bugsy's
engine as I crossed over the Sierra.  I parked him for the summer since I
was
totally burned out and needed some time behind Austin's wheel while the
sunburn faded and the Morris got built.  By Christmas, I got around to
pulling
the motor and finding two shot pistons with HUGE wear pockets in their sides
where the pieces of broken ring were living like mice in a burrow.  A
beautiful silvery aluminum sheen covered the bottom of the oil pan.

The low GBPound inspired me to get some nice Mini racing pistons (Omega
Turbo,
11cc dish) and rebuild the motor.  Now the fun part.
The higher compression ratio made it a completely different motor, so how
would the EFI computer deal with it?  Megasquirt has software available that
autotunes the fuelling tables while you drive, based on the wide-band O2
sensor and the desired AFR tables(air/fuel ratio).
I set it for "Autotune" and set out slowly around the neighborhood.  Bumpy
and
a bit lean at times, it slowly adjusted the fuelling table until it was
running very nicely.  A few hot passes on the freeway to setup the "boost"
parts of the table and I'm back in business driving him to work today.  To
the
few Sprite guys whove ridden in Bugsy or lined up next to him over the
years,
BAD NEWS!
He's faster!!!!!!!!!  The rise in compression resulted in most every box in
the fuelling table bumping up a few numbers.  That makes sense when you feel
the extra HP its producing now.  No needles to file, no floats to adjust, no
springs to trim or stretch and no dark garage time with a Colortune.  The
plugs show perfect color.

Valuable tip if you're planning to run a turbocharger or supercharger:
Increase the ring gap a few thou. It really matters!

Glen Byrns
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