weber carbs
Posted By : Nigel Gibbins, 18-Nov-2005, 04:50pm
Webers or Dellorto carbs are probably one of the best carbs you can fit to your triumph (and others). They are far more reliable than
SU/Stromberg/Solex (whatever). I expect the 'horror' shories you are hearing are from people who fittted them for the wrong reasons and just expected
them to work without setting up.
There are a few very important considerations to make here before you continue.
They are expensive to fit (even second hand ones) and you'll need to correct manifolds to fit them.
They will not give you instant power. If you do not get them set up on a rolling road you will most likely find they simply out your fuel bills up.
You absolutely MUST budget for a two hour rolling road session after you have fitted them - there are many components that can be changed to get them spot on - this will take time.
Once they are set-up, DO NOT TOUCH THEM AGAIN! even taking them off and re-fitting them can affect them (balance)
With triple carbs, the real challenge is to balance the throttles properly and only the right equipment will do.
You will probably not see much of an improvement unless you are adding modified cams, porting the head...etc etc as well.
But the good news... with the correct set-up you should see a power figure that can match a fuel injection setup (about 99%).
However, twin HS6s would also give a good return and at the bottom end there really isn't much to choose from, when you get to the top of the rev range though the webers will definately be better. A compromise would be a triple SU set up... this should give the best overall balance of power economy a drive-ablility and still looks great!
Hope this helps...
There are a few very important considerations to make here before you continue.
They are expensive to fit (even second hand ones) and you'll need to correct manifolds to fit them.
They will not give you instant power. If you do not get them set up on a rolling road you will most likely find they simply out your fuel bills up.
You absolutely MUST budget for a two hour rolling road session after you have fitted them - there are many components that can be changed to get them spot on - this will take time.
Once they are set-up, DO NOT TOUCH THEM AGAIN! even taking them off and re-fitting them can affect them (balance)
With triple carbs, the real challenge is to balance the throttles properly and only the right equipment will do.
You will probably not see much of an improvement unless you are adding modified cams, porting the head...etc etc as well.
But the good news... with the correct set-up you should see a power figure that can match a fuel injection setup (about 99%).
However, twin HS6s would also give a good return and at the bottom end there really isn't much to choose from, when you get to the top of the rev range though the webers will definately be better. A compromise would be a triple SU set up... this should give the best overall balance of power economy a drive-ablility and still looks great!
Hope this helps...
weber carbs
Posted By : David Thompson, 18-Nov-2005, 08:34pm
Hi John,
I can't speak for the 2.5l engine but have quite a bit of experience with the 2l unit in a GT6. I have at various times run Stromberg 1.2", SU 1.75" and triple Webers. It all depends what you are trying to achieve. The Strombergs in good condition are great carbs for a standard road going engine. They are not however, easily tuned. If you want a mild tune go for twin SUs. They are readily available, comparatively cheap (compared with webers) and as you only have needles and jets to change, tuning is quite straight forward and cheap. Don't expect a big advantage over the Strombergs though - just greater flexibility in tuning. You don't state what else you are doing with the engine so it's difficult to match carbs to your requirements. I wouldn't bother with triple SUs - if your going full house go for triple Webers. And on to Webers. These are expensive! You will absolutely have to have them tuned on a rolling road or dyno. Remember with a triple Weber set up you have to consider the cost of the carbs and manifold and linkages. On top of that you may need to change the venturis (x 6), the emulsion tubes, accelerator pumps, jets etc etc. Also if you buy second hand you must ensure that the carbs are a matched set. You could end up spending &163;1000 for the whole set up and unless you have the head, cam and exhaust to match you won't see any real benefits.
It really depends upon what you are doing with the engine tune. Standard road car - keep the Stombergs, mild tune - go for SUs, full house head, cam, exhaust - go for webers - but don't forget to budget for the extra fuel bill!
Cheers!
I can't speak for the 2.5l engine but have quite a bit of experience with the 2l unit in a GT6. I have at various times run Stromberg 1.2", SU 1.75" and triple Webers. It all depends what you are trying to achieve. The Strombergs in good condition are great carbs for a standard road going engine. They are not however, easily tuned. If you want a mild tune go for twin SUs. They are readily available, comparatively cheap (compared with webers) and as you only have needles and jets to change, tuning is quite straight forward and cheap. Don't expect a big advantage over the Strombergs though - just greater flexibility in tuning. You don't state what else you are doing with the engine so it's difficult to match carbs to your requirements. I wouldn't bother with triple SUs - if your going full house go for triple Webers. And on to Webers. These are expensive! You will absolutely have to have them tuned on a rolling road or dyno. Remember with a triple Weber set up you have to consider the cost of the carbs and manifold and linkages. On top of that you may need to change the venturis (x 6), the emulsion tubes, accelerator pumps, jets etc etc. Also if you buy second hand you must ensure that the carbs are a matched set. You could end up spending &163;1000 for the whole set up and unless you have the head, cam and exhaust to match you won't see any real benefits.
It really depends upon what you are doing with the engine tune. Standard road car - keep the Stombergs, mild tune - go for SUs, full house head, cam, exhaust - go for webers - but don't forget to budget for the extra fuel bill!
Cheers!
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weber carbs
Posted By : Steve Smith, 18-Nov-2005, 10:51pm
All good points made above and I have little to add. I had to learn setup and balancing these things and it's important to know how. On our side of the pond I find ordering ANY tuning parts an aggravation as they never stock six of anything, only four naturally enough. I don't think I would do it for a street car but I'd not consider anything else for a racer.
Finally, if you're not discouraged yet I have a Cannon manifold for a TR6 that you can get pretty cheaply. Steve-
weber carbs
Posted By : John Schwartz, 18-Nov-2005, 11:11pm
Hello -------wow i realy love the response all you guys left and the info ----this club is already worth my dues ------well to go on further my plan was to build a nice healthy 2.5 tr6 --engine --kent cam --headers --free flowing exhaust --and i just love the webers look and performance --realizing of course the tunning essues ---but i do have acccess to a dyno ---now aint that a great plus ---he he ---and balance the setup --well agian i do thank you all -----cheers ------John
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weber carbs
Posted By : John Schwartz, 18-Nov-2005, 11:31pm
i realy thank everyone for the response ---thank-you agian ----im going with webers --cheers -----John
weber carbs
Posted By : John Schwartz, 19-Nov-2005, 01:09pm
hi ------thank you everyone -----great info cheers John