In a message dated 3/4/99 4:00:53 PM Pacific Standard Time, tburt@hirose.com
writes:
<<
Okay, okay! I've tuned up V8s before and never any had problems. I just
never handled high performance engines.
My '57 has a late 60's 327 that I had replaced coil, points, cap, rotor,
and added a complete set of Accel high performance ignition wires. Plugs
look okay and didn't need replacement.
It starts on first pop, almost like it has electronic ignition and idles
quite well. But, when I take it out on the road, it misses badly...dang!
I am a little frustrated with this one.
Q: Got any ideas?
Note: It has a Edelbrock 4bbl and idles about 1100 RPM and there is
commonly the smell of raw gas after shutting it down. When running idle
the exhaust fumes are quite rich (wife gets angry..says it chokes out the
entire neighborhood). It's set up with a Edelbrock hi-rise and headers, so
there's no flow restriction there. The mis-firing is not consistent and is
at times random.
Q: Could the fuel mixture be too rich and occasionally (maybe randomly)
fouling the plugs while on the fly?
Tom B. 57 Stepside 3200 >>
I'd be wondering about the high idle, 1100 is too high, IMO, maybe you're
running over on the idle circuits? Does adjusting the mixture screws have any
effect on the idle? If not, you need to do some carb work/adjusting.
Did the motor run good before the tune up? If so, recheck the dwell, and
verify the plug wire routing again, you'd be suprised how well a SBC can run
with a few swapped wires.
Which type of intake is the Edelbrock? Single plane manifolds give terrible
vacuum signal at idle, if you don't have a dual plane, you're losing a lot of
streetable HP and torque.
When you say hi-performance motor, do you know the CR, and cam specs?
Have you checked base timing and full timing? Base shoul be somewhere
between 8-12* BTDC around 700 rpms, full advance between 34 and 36* BTDC, all
in around 2800-3000 rpms.
Mike
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