weber 40 dcnf modify carb question?
- Thread starter bill
- Start date
re
that might not be a bad idea. pierce manifolds said allot of people have tried to get them to work on their fiat and the mods are internal. when i asked what they where i was told it was complicated. someone may be interested in them for there x just don't want to steer them in the wrong direction
that might not be a bad idea. pierce manifolds said allot of people have tried to get them to work on their fiat and the mods are internal. when i asked what they where i was told it was complicated. someone may be interested in them for there x just don't want to steer them in the wrong direction
bb4re
86X 22,000 miles
I guess I don't understand...
...the question. DCNFs can be bolted right on a correct manifold and run, from everything I have seen. Just needed to be jetted correctly. I have purchased DCNFs that were from a VW application before and put them directly on an X manifold. Standard rebuild and mount 'em up. DCNFs are run on a variety of different car brands.
Are you looking to put DCNFs that came off of an X onto a VW, or the opposite?
...the question. DCNFs can be bolted right on a correct manifold and run, from everything I have seen. Just needed to be jetted correctly. I have purchased DCNFs that were from a VW application before and put them directly on an X manifold. Standard rebuild and mount 'em up. DCNFs are run on a variety of different car brands.
Are you looking to put DCNFs that came off of an X onto a VW, or the opposite?
dcnf
the mod that i'm refering to was to fix the carb from going dry around a corner. I guess the 40 dcnf did not handle the bug's engine placement too well and the fuel would lean over in the bowl and starve the engine of fuel. The number on the carbs is 102 they came off of a 83 MG well 2 MG's. pierce said they would work on a x1/9 as long as this mod was not done. the large chokes are 30's witch is about right the small ones however stick up about 1 to 2 inches out of the chamber and say 2.5 the smallest ones that are listed in my book a
re 3.0 . no airhorns are on them. I know they came from europe as MG did not sell cars here in 83. I have the 45 dcoe setup all ready for my car but the dcnf's are a puzzle. they look like the pic above but no horns
the mod that i'm refering to was to fix the carb from going dry around a corner. I guess the 40 dcnf did not handle the bug's engine placement too well and the fuel would lean over in the bowl and starve the engine of fuel. The number on the carbs is 102 they came off of a 83 MG well 2 MG's. pierce said they would work on a x1/9 as long as this mod was not done. the large chokes are 30's witch is about right the small ones however stick up about 1 to 2 inches out of the chamber and say 2.5 the smallest ones that are listed in my book a
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fiatfactory
Steve Cecchele
DCNF's were designed by Eduardo to have the float bowl oriented towards the front of the car, obviously in a VW application they get mounted 90 degrees off to this, and yes that can create tuning problems as described.
To modify them for an X19 wouldn't be that hard, the Aux venturi size is the orifice size (in mm squared) of the opening for the fuel to issue from...generally a DCNF 12 has 4.5's ... if these have 2.5's fitted that would be one (set of) calibrated part(s) that would need replacing, as with 2.5's the carbs would be pulling from the main jet circuit too early.
Other issues would be the carb interlink for balance adjustment, and throttle actuation to suit the X19 application, then the usual idle jet, main jet, air corrector jet, emulsion tube, and main venturi size selection (x 4 for all these) as well as pump jet and pump cam (x 2) considerations to suit the tune and capacity of the motor you'll be fitting them to, with all these calibrated parts possibly needing to be changed though, the cost can add up quite quickly.
SteveC
To modify them for an X19 wouldn't be that hard, the Aux venturi size is the orifice size (in mm squared) of the opening for the fuel to issue from...generally a DCNF 12 has 4.5's ... if these have 2.5's fitted that would be one (set of) calibrated part(s) that would need replacing, as with 2.5's the carbs would be pulling from the main jet circuit too early.
Other issues would be the carb interlink for balance adjustment, and throttle actuation to suit the X19 application, then the usual idle jet, main jet, air corrector jet, emulsion tube, and main venturi size selection (x 4 for all these) as well as pump jet and pump cam (x 2) considerations to suit the tune and capacity of the motor you'll be fitting them to, with all these calibrated parts possibly needing to be changed though, the cost can add up quite quickly.
SteveC
Black-Tooth
Tony Natoli
Yep... just as Steve says...
Yours are no good... Send them to me so I can PROPERLY dispose of them for you. The manifold and linkage as well... (hehehe...)
BTW... just lit off a pair on ol' WRXDREW's on Saturday that used to be on his brother's X1/9. We have NO idea what the tube/rod/jets are set up for... but once it started (chokeless on an 80 degree day) it almost immediately ran like STINK! No issues with cornering or any others that I could see/hear/feel. They really start to work (and are LOUD) on that little 1300 from about 4000 rpms on up! Yet we were still able to drive smoothly and quietly at lower rpms without a stumble.
They were, and are, either tuned correctly or we were pretty damn lucky! It'll take a dyno and an expert to get more outta them.
Good luck with yours!
Yours are no good... Send them to me so I can PROPERLY dispose of them for you. The manifold and linkage as well... (hehehe...)
BTW... just lit off a pair on ol' WRXDREW's on Saturday that used to be on his brother's X1/9. We have NO idea what the tube/rod/jets are set up for... but once it started (chokeless on an 80 degree day) it almost immediately ran like STINK! No issues with cornering or any others that I could see/hear/feel. They really start to work (and are LOUD) on that little 1300 from about 4000 rpms on up! Yet we were still able to drive smoothly and quietly at lower rpms without a stumble.
They were, and are, either tuned correctly or we were pretty damn lucky! It'll take a dyno and an expert to get more outta them.
Good luck with yours!
dcnf's
the manifold is fine it's a PBS manifold, jets, banjo's, heat shields, linkage "stock" where all done by me and are ok, it's the other pieces on the carbs that have been bugged:laugh:. but this mod is tough to figure out if you have never worked with a 40 dcnf before.
Thanks Steve for your help on this. hopefully nowone else will get bugged:shock:
bill
the manifold is fine it's a PBS manifold, jets, banjo's, heat shields, linkage "stock" where all done by me and are ok, it's the other pieces on the carbs that have been bugged:laugh:. but this mod is tough to figure out if you have never worked with a 40 dcnf before.
Thanks Steve for your help on this. hopefully nowone else will get bugged:shock:
bill