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weber DCOEs anyone???
- Thread starter ramajon
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Randy Forbes
Yoda
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I am.
anthony7777
Yoda
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randy,nice setup, very well adjusted,the carbs that is! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/cheers.gif
Randy Forbes
Yoda
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[ QUOTE ]
randy,nice setup, very well adjusted,the carbs that is! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/cheers.gif
[/ QUOTE ]
The Weber's have few emotional problems, and have cost me very little in therapy sessions /ubbthreads/images/graemlins/crazyeyes.gif
randy,nice setup, very well adjusted,the carbs that is! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/cheers.gif
[/ QUOTE ]
The Weber's have few emotional problems, and have cost me very little in therapy sessions /ubbthreads/images/graemlins/crazyeyes.gif
Randy Forbes
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[ QUOTE ]
Hi Randy,
Where did you get the “carbtune” I can’t make out the word underneath? I will need one of those in the near future.
Thanks,
Greg
[/ QUOTE ]
Here you go: https://www.carbtune.com/
Hi Randy,
Where did you get the “carbtune” I can’t make out the word underneath? I will need one of those in the near future.
Thanks,
Greg
[/ QUOTE ]
Here you go: https://www.carbtune.com/
JamesWilson
Yoda
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A useful site.
And they have a wry sense of humour:
[ QUOTE ]
Q. I have a 5 cylinder bike. How do I balance it?
A.
Ok Valentino, we don't make a 5-col Carbtune so I suggest you change to a 4-cyl bike.
[/ QUOTE ]
And they have a wry sense of humour:
[ QUOTE ]
Q. I have a 5 cylinder bike. How do I balance it?
A.
Ok Valentino, we don't make a 5-col Carbtune so I suggest you change to a 4-cyl bike.
[/ QUOTE ]
Randy Forbes
Yoda
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[ QUOTE ]
Hello Randy,
aren't the throttles on one DCOE linked? i.e. one throttle rod and two butterflies,? if so then one Carbtune would do the job?
Alec
[/ QUOTE ]
This is the way I have always balanced the independent (keyword) barrels of multiple carburation.
Hello Randy,
aren't the throttles on one DCOE linked? i.e. one throttle rod and two butterflies,? if so then one Carbtune would do the job?
Alec
[/ QUOTE ]
This is the way I have always balanced the independent (keyword) barrels of multiple carburation.
Hello Randy,
that's interesting, the answer to my question is a yes from the look of it.
The adjustment in question, I have to guess, as I have no experience of DCOE's, is necessary for a good idle as when the throttles are opened this compensation duct will have little effect.
I was interested as I have on my Triumph a fuel injected set up with three double bodied air intakes, each with a pair of throttle discs on one spindle. I balance them using just one of the two on each manifold, as there is no provision to compensate for a difference between flow into a common manifold. Any such difference is due to individual cylinder performance and if there is a large discrepancy it means a strip down to rectify.
Alec
that's interesting, the answer to my question is a yes from the look of it.
The adjustment in question, I have to guess, as I have no experience of DCOE's, is necessary for a good idle as when the throttles are opened this compensation duct will have little effect.
I was interested as I have on my Triumph a fuel injected set up with three double bodied air intakes, each with a pair of throttle discs on one spindle. I balance them using just one of the two on each manifold, as there is no provision to compensate for a difference between flow into a common manifold. Any such difference is due to individual cylinder performance and if there is a large discrepancy it means a strip down to rectify.
Alec
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Hi Alec,
Yes the throttle plates are linked. In Randy's case there is no common manifold. Each carb throat feeds one port. There are separate idle air bypass adjustments for each plate. Number 11 in Randy's pic. These will compensate for slight differences in the two throttle bores air bleed positions or throttle plate differences. Quoting from another source:
"(2) Air Compensation screws, Air bypass screws, etc. These are the needle screws with the locking nuts on them. They are used to "ensure identical vacuum below each throttle valve [plate, butterfly], and therefore ensure identical mixture during idling and progression." Lets call them Air Bypass screws."
D
Edit: Not all DCOE's have the idle air bypass adjustments, only the later models. I believe they are under the white plastic caps in Randy's seventh photo.
Yes the throttle plates are linked. In Randy's case there is no common manifold. Each carb throat feeds one port. There are separate idle air bypass adjustments for each plate. Number 11 in Randy's pic. These will compensate for slight differences in the two throttle bores air bleed positions or throttle plate differences. Quoting from another source:
"(2) Air Compensation screws, Air bypass screws, etc. These are the needle screws with the locking nuts on them. They are used to "ensure identical vacuum below each throttle valve [plate, butterfly], and therefore ensure identical mixture during idling and progression." Lets call them Air Bypass screws."
D
Edit: Not all DCOE's have the idle air bypass adjustments, only the later models. I believe they are under the white plastic caps in Randy's seventh photo.
Randy Forbes
Yoda
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[ QUOTE ]
...to "ensure identical vacuum below each throttle valve [plate, butterfly], and therefore ensure identical mixture during idling and progression."
D
[/ QUOTE ]
Therein lies the secret to perfect throttle response; whether a minute change in throttle opening, or straight to the floor.
You've GOT to get the "progression" stage right if you want truly dependable throttle response. Naturally, main circuit fuel & air jets play an ultimate performance role, but the idle circuit jets are in "demand" 90% of the time (maybe more) and most of the engine's fuel diet is metered through them.
Here's a brief pictorial summary of the 45 DCOE's operating components:
...to "ensure identical vacuum below each throttle valve [plate, butterfly], and therefore ensure identical mixture during idling and progression."
D
[/ QUOTE ]
Therein lies the secret to perfect throttle response; whether a minute change in throttle opening, or straight to the floor.
You've GOT to get the "progression" stage right if you want truly dependable throttle response. Naturally, main circuit fuel & air jets play an ultimate performance role, but the idle circuit jets are in "demand" 90% of the time (maybe more) and most of the engine's fuel diet is metered through them.
Here's a brief pictorial summary of the 45 DCOE's operating components:
Randy Forbes
Yoda
Offline
[ QUOTE ]
where do you get the vacuum pick-up?
I have not seen DCOEs with a place to attach the rubber hose
Beaulieu
[/ QUOTE ]
where do you get the vacuum pick-up?
I have not seen DCOEs with a place to attach the rubber hose
Beaulieu
[/ QUOTE ]
anthony7777
Yoda
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randy,what kind of distributor is that in the picture? im thinking of going "petronics" . /ubbthreads/images/graemlins/cheers.gif
GregW
Yoda
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Hello Dave, Randy,
"Each carb throat feeds one port.",
Exactly as my injection manifold does.
I do find it difficult to understand that the air bleed passages have any effect once the throttle butterflies are opened, even by a small amount as the volume of air will be significantly higher down the main tract. Still looking at all the components that comprise a DCOE boggles my mind. Give me my plain simple old fashion mechanical injection system, same sort of intake roar though if I have my air cleaner off.
Alec
"Each carb throat feeds one port.",
Exactly as my injection manifold does.
I do find it difficult to understand that the air bleed passages have any effect once the throttle butterflies are opened, even by a small amount as the volume of air will be significantly higher down the main tract. Still looking at all the components that comprise a DCOE boggles my mind. Give me my plain simple old fashion mechanical injection system, same sort of intake roar though if I have my air cleaner off.
Alec
Randy Forbes
Yoda
Offline
[ QUOTE ]
Hello Dave, Randy,
"Each carb throat feeds one port.",
Exactly as my injection manifold does.
I do find it difficult to understand that the air bleed passages have any effect once the throttle butterflies are opened, even by a small amount as the volume of air will be significantly higher down the main tract. Still looking at all the components that comprise a DCOE boggles my mind. Give me my plain <u>simple</u> old fashion mechanical injection system, same sort of intake roar though if I have my air cleaner off.
Alec
[/ QUOTE ]
I guess it comes down to what you're used to; I don't find the Webers to be mind boggling, but looking at this illustration makes me dizzy...
Hello Dave, Randy,
"Each carb throat feeds one port.",
Exactly as my injection manifold does.
I do find it difficult to understand that the air bleed passages have any effect once the throttle butterflies are opened, even by a small amount as the volume of air will be significantly higher down the main tract. Still looking at all the components that comprise a DCOE boggles my mind. Give me my plain <u>simple</u> old fashion mechanical injection system, same sort of intake roar though if I have my air cleaner off.
Alec
[/ QUOTE ]
I guess it comes down to what you're used to; I don't find the Webers to be mind boggling, but looking at this illustration makes me dizzy...
beaulieu
Jedi Warrior
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"where do you get the vacuum pick-up?
I have not seen DCOEs with a place to attach the rubber hose" OK, I see now /ubbthreads/images/graemlins/smile.gif
Thanks for the photo, can you buy adapters to fit in the holes you show in the photo ?
if not what thread are they so I get the tubes off of something else ?
This looks like the correct way to adjust them , I have used the carb sync tool that you stick on the top of the carb , but its not very accurate,
The vacuum gauge looks like something the Honda 750 bike guys use !
Beaulieu
I have not seen DCOEs with a place to attach the rubber hose" OK, I see now /ubbthreads/images/graemlins/smile.gif
Thanks for the photo, can you buy adapters to fit in the holes you show in the photo ?
if not what thread are they so I get the tubes off of something else ?
This looks like the correct way to adjust them , I have used the carb sync tool that you stick on the top of the carb , but its not very accurate,
The vacuum gauge looks like something the Honda 750 bike guys use !
Beaulieu
B
BUNDYRUM
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Hello Randy, i had to chuckle and agree with your last comment, i don't like being dizzy either. All this talk of Webers reminds me of a trip to OZ i took a couple of years ago to visit family and Healey friends. One night my longest known Healey friend took me to see another Healeyite that had a 100/6 with a Weber setup. It was late at night when we went out to his garage to see his car and after he started it up and waited till the water temp showed on the gauge the car was then idling at a steady 700rpm or thereabouts. His next move was to open the throttles as fast as he could and it revved to 6000rpm without any hesitation whatsoever. With the throttles snapped shut it once again idled at 700rpm and just as smooth as can be, i was impressed to say the least. I don't remember what the cam or bore size was but i'm sure it wasn't stock. It all depends on where your priorities are and what you are willing to settle for. Thanks for the tips and also for taking the time to explain to people to help them understand. Regards, BUNDYRUM.