I'm still confused by the mis-timing of my spitfire
1500.
To reiterate the problem. When I opened the gap on the
points (as far as .025" from the initial .016"), the
car would increase idle speed significantly. And my
car's signature sputter at 3k rpms decreased pretty
significantly. It turns out that, in effect the larger
gap was advancing (?) the distributor (i think). This
was with the static set to 10deg BTDC and plugs gapped
to .025".
But adjusting the distributor housing clockwise, moves
the static and dynamic timing even further out Before
Tap Dead Center (earlier) in the crank's rotation,
right? Which I would assume would make the car run
choppy. (e.g. combustion while the piston is on an
upstroke). but it doesn't.
To be specific, with the gap set correctly to .014"
and playing with the distributor housing adjustment,
vacuum port capped and vac advance unattached. I get a
drastic increase in RPMS around 30 deg BTDC using my
timing light (this is an estimation since the scale on
the timing chain cover only goes to 20 deg BTDC).
At 10 deg BTDC (static/dynamic) the car's idle speed
drops and occasional pops and the signature sputter at
3K rpms returns. BUT the car seems to have more
torque. But any further towards ATDC than 10 deg BTDC
and the engine stumbles and eventually cuts off around
the 0 deg TDC mark.
Is this normal, or is my 1500 engine possibly have a
mis-indexed camshaft, sticking valve, worn muffler
bearing, bent kanutsen valve?
Also, putting the timing light on the #4 plug wire, I
get the crank notch appearing in the same spot in the
cranks rotation as the #1 ignition. What's with that?
Once again, 138-140 lbs. compression across all
cylinders. New bottom end bearings about 10k miles
ago. New plug wires, cap, points assembly, condensor,
rotor, plugs. All above measurements were with the
vacuum advance unattached and the vacuum port
sealed/plugged. No hunting idle. No forward/rearward
movement in the crank (thrust washers in good shape).
This is a '77 engine with dual carbs. (the sparking
tips have become slightly tanned in the past 300 miles
of driving, but are slightly toward the white range).
Last night I enrichened the carbs a half of a flat.
Trying to figure out why the car increases idle speed
so far BTDC is making my head hurt. Any ideas?
-Terry
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