Weber linkage

[Ade-TR4]

Afternoon All,

 

I have recently changed from a set of Manifolds for my DCOEs that were tipping the carbs too much (about 15-20 degrees and causing flooding) to a pair of Triumph Tune ones. These seem to hold the carbs much more "Orizontale", however, there is little provision for a linkage.

 

There is a drilled hole x 2 on each manifold, but this would require the bar to run in the aluminium casting, which I suspect would wear quite rapidly.

 

So, options:

 

1 - Adapt original SU/ Stromberg setup (is this possible?)

2 - Bodge a bracket and use the drillings for the bar and put up with possibility of wear?

3 - Convert to cable and have 1 or 2 cable controllers (having 1 would require me to lengthen the balance-bar between the carbs - I believe this is possible?)

4 - Bin the DCOEs and shove the Strombergs back on...(I'd rather not - I like the DCOEs!)

5 - ?

 

Comments, insights, photos (relevant please) etc etc.

 

Thanks, as always,

 

Ade

[TR 2100]

Ade,

 

I have 42DCOEs on both my TR4s, and both have (almost)

identical linkage.

 

I use period manifolds on each car - took quite a while to

acquire them, but worth the wait.

 

I don't like overhead linkage. Probably more effective, but

I just don't like the look of it. (as an aside, I don't like the

look of alternators either, so I have dynalites).

 

Cable linkage, again, probably more effective, but again,

I don't like the look.

 

I have used the original design linkage, although there

is a beefed up option for the rods in the US - thicker and

well bushed. Much stronger. Much less play.

 

I then used the original bell crank lever, so the last

problem was to connect the two webers in the middle.

This is where you need to have a) appropriate weber

fittings and fabricate a connection.

 

I don't pretend this is quite as effective as overhead

linkage and/or cable throttle but it works well on my

well modified engines.

 

The first time, (first car) I did this myself. Asked my

Uncle Heath for advice. Second time, TR Enterprises

fabricated something that was very similar in principle

but stronger.

 

Wish I could post a photo, but all the restoration photos

show the first setup that had overhead linkage, before

I got the manifolds and linkage sorted.

Will post/send a photo if I can find one - not back in the

UK until the middle of May.

 

AlanR

Edited April 11, 2016 by TR 2100

[Ade-TR4]

Thanks for the info Alan!

 

I too don't like the overhead version, and the cable option, although probably more accurate, isn't appealing either...

 

Cheers

Ade

[kob666e]

I made up a linkage from underneath based on the old SU set-up:

 

First I made a bracket to fit under the rear carb and is held on by the bottom two studs, used the same ball joints, just bought some UNF threaded bar. Getting the right-angle bracket was pure luck as a mate had a bunch of spares, I'm sure there would be something similar available. There is a bearing fitted into it for the linkage to pivot on:

 

Again the same SU linkage connects the right-angle to the rear carb and I extended the Weber bracket to reach the front carb (not my best welding but does the job!):

 

Added an extra spring:

Edited April 11, 2016 by kob666e

[Ade-TR4]

Like the angle bracket idea - Thanks!

 

The extension of the balance arm is what I was planning - Thanks for confirming

 

Ade

[stuart]

Thats pretty much what I have between my Dellortos, but I have the lower bracket between the two carbs with the original bell crank mounted on it.So just need to alter the length of the primary rod and then make the bracket and make a link bar between the two throttles.

Stuart.

Edited April 11, 2016 by stuart

[Ade-TR4]

Thanks Stuart, I think that will be the way to go

Ade

[kob666e]

Like the angle bracket idea - Thanks!

 

The extension of the balance arm is what I was planning - Thanks for confirming

 

Ade

The weld on the balance arm (couldn't think what it was called earlier) is for strength, they flex without added support.

 

I'm better with a stick welder and a 3.2mm rod!

[Mark1965TR4aBRG]

I had the same dilemma recently fitting my 45's, but went for the Webcon top mount as a starter.

 

I've kept the bosses on the Bastuck manifolds in case I want to mess about with crank arms and rose joints and had to extend the balance arm which was also strengthened. I've been advised to put a cross brace on the extension as well, so that will happen at some point as it's fine for now.

 

There's not a great deal of room for a lower mount and the top mount is so far working well and having lost a return spring once already it was quick to pop back on at the roadside..

Edited April 12, 2016 by Mark1965TR4aBRG

[Ade-TR4]

Thanks Mark,

 

Surprised Webcon etc don't do an extended balance arm. The TWM manifold conversion seems to have an extended female side, but I can't find it available separately.

 

Was the cable conversion simple enough? I thought I may clamp the cranked section of the throttle peddle assembly and bring the cable through the bulkhead?

 

Cheers again,

Ade

[Mark1965TR4aBRG]

Ade

 

Yes - simple enough.

 

The boys at TRGB modified my pedal with the Webcon twin throttle pull as per the pic.

 

Cables up through the bulkhead and modified in length to suit.

 

I was wanting originally to have a more 'fancy' system but this works a treat..

[Mark1965TR4aBRG]

Ade

 

Here's my cable route from the bulkhead to the throttle mechanism.

 

Need to cap the ends of the cable outers or get custom cables made up, but then I need to finish modifying my air box - then fit it, mount the air filter in the rad cowl & fit the ducting too!

Edited April 12, 2016 by Mark1965TR4aBRG

[Ade-TR4]

Nicely done

Thanks Mark!

Ade

[TorontoTim]

Hi Ade,

 

How did this turn out for you in the end?

 

Tim

[Ade-TR4]

Hi Tim,

Eventually settled on under-carb cable operated with link bar between carbs.

Seems fine so far. Tried several options!

 

Been to rolling road - all good, 120-125 BHP

Cheers

Ade