75 HP Bristol engine.

[Lewis]

And thank you Brian Cuddigan. Christmas is early this year. I recognise Holden's carb. synchroniser and will have no trouble using it as my small bonnet lifts off, no hinges. I will discuss synchroniser and balancer with my local garagiste. A wild man in his youth (once apprehended by police for driving to work at 130 mph in a 60 zone; having set up roadblocks to catch him they couldn't prove his speed and he got off) he has endured years of servicing Japanese jelly moulds and was intrigued when I came along with the eccentric HRG Bristol. He now looks after six Bristol engined cars, says they are beautifully built and easy to work on and plans to expand his business. Minions will endure the bread and butter work while he plays with proper cars.

Regards,

Lewis

[Geoff Dowdle]

Lewis,
it is quite a lengthly process to try and correct 50 plus years of abuse on
those old Solex . The most important things to look for before you start
tuning as per the manual is ......

1. Are the 3 carbs the same , especially the throttle bases, make sure they
all have the same number of progression holes ie 2 for 401 - 405 , 3 for
406 & D2 . All faces must be flat including the adapter the carbs bolt to.

2. Float levels MUST be at 16mm down from the top of the main body when the
engine is idling, this can only be measured by making up an external plastic
sight tube attached to a spare main jet holder.
The levels are adjusted by shimming the needle & seat unit in the carby top
. Note machining of the carby tops can be different different for different
Solex applications.

3. Make sure the jetting is correct , ALL JETS & Emulsion tubes. Check the
diameters with various size metric drills. Many original jets have been
incresed in size over the years by drilling out .
As a rule you should need slightly leaner jets than STD as the quality of
modern petrol is so much better than the very poor petrol of the late 40's
and early 50's

4. I usually replace the nice brass AMAL throttle rod ball joint
ends(usually badly worn) with new ones to allow the throttle butterfly's to
go back evenly on the adjustment screws.

5 Although not directly related to Carby tuning , valve clearance must be
correct, distributor MUST be in good working order , advancing correctly .
Very few Lucas distributors work well even when new, they were poorly made.
(BAC used Delco Remy twin point for all the BS engines) I usually replace
the Lucas with a modified Malloy twin point unit, thats is fully adjustable.
There is no point in converting your Lucas to electronic operation while the
advance curve is no where near correct. You must have a TDC make on either
the flywheel or fcrankshaft fan belt pulley to operate a timing light .

6 Unless you do most or all of the above you will never get a 6 cylinder
Bristol running nicely.

Must go, Good Luck
Geoff Dowdle
I

[Claude]

This Needs To Go In The Bristol Car Owners Book!!!

[Ashley James]

It's taken me months of alternating between Geoff and Samaritans
before I got it somewhere handy. At one point i think Geoff wanted
Samaritans number too!

Ashley

[Lewis]

Panic over. The little HRG Bristol is running like a Swiss watch. I downloaded
the JEL450 Bristol Carburetor Tuning manuel and employed the Holden Vintage and Classic UK balancer that arrived in the mail this morning.

The years fell away and I was back playing with my first 403 in 1964. So simple; disconnect everything, wind it all back to scratch, factory settings, reconnect linkages identically with finest possible tolerances, a little adjustment and I might have a turbine under the bonnet.

Only two snags, the local garagiste, who is now caring for four Bristols, has appropriated the balancer and I have had to order another from Holden, who are terribly excited and have sent me twenty emails in as many minutes.

Lewis.

[Ashley James]

I just bought one! I've the car almost perfect but know from
balancing motorcycle carbs how important it is to get the throttles
exactly the same. I was going to use a Morgan Carbtune through holes
in the pilots jets, but this is easier.

Holdens are the most expensive company on the planet along with
Frosts, but they do sometime have things you can't find elswhere.

Ashley

[Geoff Dowdle]

To tune the Solex correctly you have to balance the air flow of each carb
, and balance the vacuum on the idle system with in each carb .
If you have a 404/405 Workshop Manual there are details on how to do this .
Most owners use a Holden type air flow balancer and then just screw the
idle mixture screws in or out until the beat of the engine changes then
screw it out about half a turn ,this gets the idle mixtures pretty close.

But the 404/405 manual has detail instructions of how to make your own
triple Manometer , using this the airflow of the three carbs can be adjusted
together (as adjustment of the airflw of one carb can slightly adjust the
air flow of the other two ) . Once the airflows are matched you use the
triple manometer to balance the vacuum at the pilot jets , this is adjusted
by screwing the idle mixture screws in or out .
Then if the carbs are a matched set , jetted correctly and in good condition
you have a chance of tuning the old Solexes correctly .
IT IS WELL WORTHWHILE TAKING THE TIME AND VERY LITTLE MONEY TO MAKE YOUR OWN
TRIPLE MANOMETER.
Every 6 cylinder Bristol owner should have one.

Geoff