[Healeys] FW: HD8 Slow Run Valve

[John Sims]

Before you do anything with the carbs you must be sure that your timing is
correct.

John Sims, BN6
Aberdeen, NJ
 
http://www.healey6.com


-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of Bob Spidell
Sent: Sunday, July 18, 2010 8:31 PM
To: Bob Johnson
Cc: Healeys
Subject: Re: [Healeys] HD8 Slow Run Valve

Bob,

I have one SU book that says to close the slow run valves and adjust the
idle with the throttle stops only, and one that says, essentially, that 'the
idle must be set only with the slow run valves.'  Go figure.

I split the difference.  In my experience, the SR valves will only give
600rpm without opening them what I consider an inordinate number of turns.
I like to open the SR valves 2 turns--this gives me some leeway if I want to
slow or speed up the idle depending on conditions (usually, altitude); i.e.
you can open each valve a half turn, then close them back without breaking
out the synchronizer (and removing the air cleaners--a major PITA).  I also
open the throttles a smidgen with the throttle stop screws.  I prefer to
have the stops stop the throttle plates--not the inside of the throttle
body.  I have seen where throttle plates have worn a groove inside the carb
throat, all but ruining the carbs.

The procedure is:

1) close slow run valves
2) adjust and synchronize the carbs with the throttle stops
3) open the SR valves 2 turns--check synchronization (should be pretty
close)
4) close the throttle screws until desired idle achieved (I like about
750rpm)
5) check synchronization
6) repeat steps 1-5 as necessary (then, you can start on the fast idle
settings)

All this notwithstanding, your car should idle steady--if a bit rough--at
600rpm on the slow run valves only.  Since your engine stalls, something
else is not right.  My guess would be timing, dwell and/or mixture.


bs