On HD8s, cracking the throttle plates open works ok but bypasses the
purpose of the slow run valve, which is to give you a nice steady &
smooth idle. If you crack the throttle plates open, you'll have a
couple hundred RPM variation depending on temp / conditions, etc.
Incidentally on a car with triple HD8s like an S1 E-Type you'll never
get idle below 800 or so if you crack open the plates.
On 7/19/10, John Sims <ahbn6@verizon.net> wrote:
> 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@autox.team.net [mailto:healeys-bounces@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
> _______________________________________________
> Healeys@autox.team.net
> Donate: http://www.team.net/donate.html
> Suggested annual donation $12.75
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/healey.nut@gmail.com
>
--
Sent from my mobile device
_______________________________________________
Healeys@autox.team.net
Donate: http://www.team.net/donate.html
Suggested annual donation $12.75
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|