Weber Manifold

[cord]

Working on a UK TR6 head, are there different weber manifolds available or are all the suppliers selling the same?

Thanks in advance.

[Guest ntc]

Yes two types one good and one not so good avoid the one with rose linkage bar mounts

[cord]

Thanks Neil.

Any idea who supplies the better one?

[Guest ntc]

You need to find a TWM like this solid linkage not bell crank

[cord]

Thanks Neil for the advise

[stuart]

That will mean finding a s/hand one as the new TWM ones are on the rose joints.

Stuart.

[cord]

Thanks again for the advise. Is there a major problem with the rose jointed pedestals? It looks, as far as I can make out, that Moss are selling the TWM manifold. Is there difference between what Moss are selling and the Webcon manifold?

[roy53]

There is another option BASTUCK but would avoid as poor casting and fit.That should have been very very poor.

Rose jointed ??? await the reply on these as i have had no problems YET

[Guest ntc]

Roy

They are shipped without a lock nut ( Metric) and do work loose and knacker the threads,also without you will not be in sync for long

[Tom Fremont]

CANNON make a manifold which is popular over here; I've put over 100K miles on one which happened to have TWM linkage arms and a ball-bearinged bell crank. The Cannon has balance tubes where I believe the TWMs don't. This should make synching the throttles less critical.

 

My cars are LHD however, and I don't know what implications RHD would have for a CANNON manifold.

 

If anyone is wondering, CANNON make versions for both the early carb heads and the later, wide-port-spaced type.

Edited September 4, 2013 by Tom Fremont

[foster461]

I also have the Cannon manifold and the cheap cannon pressed steel linkage. I'd like to move up to a larger diameter stainless bar, better quality posts and the alu cantilever arms but I'm not sure there is enough meat on that manifold to dril and tap for the larger diameter post threads.

 

Stan

[Tom Fremont]

I think I have what you want, Stan - see if Pierce can furnish the same stuff to you as he did for me.

 

[Guest ntc]

The Cannon has balance tubes

 

No Idea Tom? If they are how on earth do you guys set the air mixture screws on each pot

Edited September 4, 2013 by ntc

[Andy K]

Thanks again for the advise. Is there a major problem with the rose jointed pedestals? It looks, as far as I can make out, that Moss are selling the TWM manifold. Is there difference between what Moss are selling and the Webcon manifold?

Hi. I have a rose jointed TWM manifold with 3 X Dellortos and a Revington airbox. Set up over ten years ago now, no problems, doesn't work loose or go out of sync. Occasional adjustment of the group for the idle. Threadlocked everything and joints occasionally lubricated.

[foster461]

I think I have what you want, Stan - see if Pierce can furnish the same stuff to you as he did for me.

 

 

 

I actually have all the bits from Mike, what remains is to drill and helicoil the manifold for the bigger posts. I had to go up a size in the thread on the posts to get the posts that fit the larger diameter bar. At least I think thats whats happend, the TR3 project interrupted my TR6 plans and I never got back to it !.

 

Stan

[Guest ntc]

There is no wonder you guys over the pond struggle

[Tom Fremont]

No Idea Tom? If they are how on earth do you guys set the air mixture screws on each pot

 

These have been around for quite a while, decades I reckon so have stood the test of time. Good chance there are more of these out there than the TWMs for 6-pot TRs since 10X as many came over here.

 

If by " air mixture screws " you refer to the bypass on 151 series late-model DCOEs I don't know why it would matter much. Perhaps the balance tubes obviate the feature; many just leave them closed. None of my carbs have the feature anyway, and they do register differently from barrel to barrel with a synchro meter so I adjust the throttle stop screws to balance them. FWIW, my driver with its P.I. cam will hold a 550 rpm idle if I want it to ( o/p drops below my pain threshold when hot hot hot however ).

 

As for struggling, when all else is as it should be joy is not hard to come by; just takes perseverance. As I've posited before, Weber conversions on TR250/6 U.S. spec cars were virtually prohibited for road use due to emissions controls which, if I understand correctly, are still applicable to the last year or two of production in California at least. Without a higher duration cam there isn't much you can do with one of these unless supercharging. So Weber-wise we're way behind the RoW in TRdom for the 6-pots anyway.

[Tom Fremont]

 

I actually have all the bits from Mike, what remains is to drill and helicoil the manifold for the bigger posts. I had to go up a size in the thread on the posts to get the posts that fit the larger diameter bar. At least I think thats whats happend, the TR3 project interrupted my TR6 plans and I never got back to it !.

 

Stan

 

I didn't have to enlarge any threads on mine. It's been several years ago, so maybe they forgot something...

[Guest ntc]

Tom

If only yours and Stan's car's was here

[stuart]

With the amount of money spent so far trying to get them right it might have been cheaper to ship them over and sort them out here

Stuart.

[foster461]

With the amount of money spent so far trying to get them right it might have been cheaper to ship them over and sort them out here

Stuart.

 

No kidding. I'm 5 years into the Weber project and still working on it.

 

Stan

[Stanpartmanpartwolf]

TWM: Excellent kit for motorsport; three issues:

Firstly: bin the double O ring mounts & use genuine 1-piece Misab rings. Loctite the studs in & use the PVC donut & cup kit, NOT Thackeray washers. Carburettor suspension is not really important, though, on a straight 6- it is absolutely crucial on a straight 4.

Secondly: the throttle action using the LHD rod linkage is savage, far shorter than original- consider redrilling the cross-shaft crank to reduce its arc of operation. This is not an issue on RHD cabled installations.

Thirdly: the servo take-off on #6 barrel alone soon ruins the non-return valve & renders the servo & brakes ineffective.

 

Cannon: Surprisingly good, despite the feeble-looking linkages. I would use the manifold unmodified on a road car, simply because the common chamber provides a steady vacuum for the servo & distributor.

On race engines, I have filled the balance tubes with, er, ahem, Sikkaflex, thus providing a stronger signal to each barrel's set of jets. Rightly or wrongly, set-up seems more straightforward.

 

Bastuck: yet another of their copies- notes as for TWM, but the stud holes are drilled by Clarence The Lion.

 

Triumphtune 3-piece manifold: no longer available, thank God. Avoid at all costs.

 

My latest silly TR6 "road" engine runs six Mikuni bike carbs on hand-made manifolds & has absolutely razor-sharp throttle response. We currently have 170RWHP @5500rpm with another 1200rpm to use once we can get sufficient top-end fuelling..

SPMPW

[Guest ntc]

the servo take-off on #6 barrel alone soon ruins the non-return valve & renders the servo & brakes ineffective Quote

 

Stan

It makes it click but that's it,put one inline,and Webers do not like a vacuum dizzy

Edited September 7, 2013 by ntc

[Stanpartmanpartwolf]

Not so. The chattering & audible clicking can damage the valve; I have seen it on two or three cars. You got anything useful to add?

[Guest ntc]

!

Edited September 8, 2013 by ntc