Continued from Part 1.......
EFFORTS TO SOLVE THE PROBLEM: Eventually, at the hands of a mechanic who
races a Bugeye, we got it sounding about right. But, when I drove it down
the road at 4000 RPM for a few moments, the EGT on the rear header tube went
to 1400 degrees and rising-- (I didn't wait to see where it leveled out).
Richening the rear carb seemed to make a difference in rear EGT, but then
the car ran like it was overly rich, eventually loading up and fouling at
least one spark plug. If I got it running pretty good at high idle and the
lower RPM ranges, I could make it accellerate okay IF I pressed the throttle
SLOWLY. If I nailed it, it would again act rich and miss and load.
Began substituting carb jet needles and experimenting with needle height a
bit. Not much improvement, although it seemed to run best with #5 needles.
.... And then I tried the following, some things several times and in
different combinations:
-- dumped gasoline and refilled with fresh premium pump gas
-- valve adjustment to cam grinder's rec.
-- compression check- 145-155# cold across all 4 (seemed low, but new
rings?).
-- timing check- 31 degrees at full advance.
-- tried four different heat ranges of NGK plugs including some sort of
racing snow mobile plugs that made Gary Kropf's Bugeye run like gangbusters.
-- replaced Pertronix with new points and condenser.
-- substituted a different coil.
-- replaced high-tension ignition wires.
-- measured float bowl fuel levels.
-- replaced Grosejets with float needles and back again.
-- checked size of float bowl inlet valve
-- checked float-to-jet fuel tube for hidden kink
-- checked fuel pressure and tried various pressures between 1.75 and 4 psi.
-- took out and put back the dashpot springs.
-- sprayed propane, carb cleaner, and WD40 around intake joints looking for
air leak.
-- replaced warped heat shield thinking it was bad karma.
-- replaced intake gaskets.
-- machined bakelite carb spacers for O-ring seals and put in place of
gaskets.
-- went back to gaskets, but schmeared RTV on them a bit.
-- substituted a pair of 1/1/4 carbs (not rebuilt, unknown quality but
looked stock) from a Mini Cooper. This got rid of the richness
NO CONSISTENT IMPROVEMENT. OUT OF MONEY. OUT OF FRIENDS. By now, racing
season was over in Michigan.
Pulled the motor.
Checked cam timing using #1 intake lobe. Cam grinder's spec is 107 degrees.
I measured right at 107 degrees using a straight-up woodruff key and stock
cam sprockets.
Did a leak-down test. A little hissing past a couple of valves, none into
water passages.
Pulled the head.
Some mild discoloration around #2 and 3 bores fanning out toward the pushrod
holes. Gasket looked good.
Had the head pressure tested for cracks. No cracks. No significant leakage
around valves. Valves removed and guides inspected. Nothing broken or
loose.
Had the head milled. Machinist said he took very little off to make it flat
and did not think that was the problem.
I have a pistol.
It's loaded.
Don't make me use it!
What do you REAL gearheads think I should try next (before I pull the
trigger)?
JohnD
#49 Works Midget Vintage Racer what don't work
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