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From: steve sage
>Hello Everyone:
>I need some Alpine advice for my '67 Series V. I had my 1725 engine
>rebuilt a few months ago and it has been quite "zippy" until recently,
>the only problem was that I couldn't get it to idle smoothly below 1200
>RPM.. I started having problems starting it when cold, and got a couple
>of backfires through the Strombergs.
Look at yer plugs. that will tell you which carb is puking.
>I wonder if I've got the valves set too loose now (would this cause
>sluggish acceleration?) and should instead only adjust them when "very
>hot" as the shop manual advises. What are the performance results, if
>any, of valves being on the looser or the tighter side? Could that start
>up "stumble" be a bad PCV valve?
I am assumimg that Dan Walters gave you your advise on the valves.
I have never adjusted them cold, except to rough them in for running
an engine to temp, then adjusting them proper.
The valve clearances decrease with temperature, so adjusting them
cold can get you into trouble if the clearances go away and leave
the valves never seating.
Also, rockers tend to wear on the face, so be certain that you dont
have a groove where the stem contacts the rocker. This makes
valve clearance measurment impossible.
Trust me here, Ive been there.
Stombegs are persnickety little critters.
Sounds like you have a sticking piston.
If you can lift the pistons and allow them to drop, there should
be a click when the piston strikes the carb. Both pistons should
fal at the same rate, and should not get hung up along the way.
This test should be perfomed both hot and cold to account for
the differential of expansion of all materials.
If it doesnt pass above test, (probably wont), you will need
to remove the piston cover screws, then carefully tighten the screws
little by little crisscross till you can torque it all down.
Never touch those screws again.
Next, centralize the needles to the main jet using the rootes
procedure. Dont know it, ask.
Last, synchronise the jet positions by screwing the jets all
the way in (jet centralization proc will ask you to do this), then
back out XC number of turns.
The above proceedure is important because of the close
clearances of the pistons to the carb, and the needle to the
jet.
Put some damper oil in the tops, then retest for bind and
rate of fall.
If the carbs are in reasonable shape, the car should run great.
Lastly, verify that ubrupt openings of the throttle result in
the same rate of piston opening, and the same static
piston positions.
The stromberg carbs are persnickety, but once setup
properly, run troublefree for years.
Jarrid Gross
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