48mm Carbs

1614 Views 10 Replies 5 Participants Last post by Jay Aldred, Oct 8, 2006

aussie1

Discussion Starter · Oct 5, 2006

Anyone have any preferences between Dellorto 48 DRLA and Weber 48 IDF?

I could also have a pair of 45 Dellorto's - would i notice much difference with these on a 2276cc over the 48's?

What should a good condition pair of either of these be costing?

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VielziDub

· #2 · Oct 5, 2006

I know you can get DRLA 48's which are tri-jets and have an extra enrichment circuit, and thus become more streetable.

I would be interested in you DRLA 45's if you were to sell them.

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aussie1

Discussion Starter · #3 · Oct 6, 2006

VielziDub said:
I know you can get DRLA 48's which are tri-jets and have an extra enrichment circuit, and thus become more streetable.

I would be interested in you DRLA 45's if you were to sell them.

Do the Webers have tri-jets or is this only on the Dells? Is that why people seem to prefer the Dells over the Webers?

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Fastorq

· #4 · Oct 6, 2006

The DellOrto TriJets are no longer available as new carbs. (The trijet circuit is actually cast in to all DellOrto bodies but only ever used in the 48mm carbs.)
Interestingly some early model IDF webers had a similar enrichment circuit but instead of a passageway in the carb body with a screwed in jet in the base of the float chamber , the Webers had a brass capillery tube reaching down into the bottom of the float chamber: but it did the same job.

The "extra" enrichment circuit doesnt actually make the trijet carbs more streetable but what it does is deliver an additional charge of fuel down into the throat of the carb at high RPM s

Both the Weber version and the DellOrto version work on the basic physics principle , that as you accellerate, the creation of the low pressure area which causes the carb to operate , moves upward .

As the Trijets capillery extends up even further than the aux vent fuel inlet it allows even more fuel to be introduced at the top end ie at high RPMs.

Dells vs Webers ??? up to 48mm size carbs most people would agree that Dells are better than Webers (you would expect that as the Dells are copied from the Webers and slightly improved.)
When you get to 48mm carbs on a large displacement engine my preference would be 48 mm IDF Webers

Ive got a set of DellOrto TriJets that were on an imported race car ,
(The red car that Ant used to race) the Dells were changed to Weber IDAs but apparently they made almost no difference !

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Fastorq

· #5 · Oct 6, 2006

VielziDub said:
I know you can get DRLA 48's which are tri-jets and have an extra enrichment circuit, and thus become more streetable.

I would be interested in you DRLA 45's if you were to sell them.

I think you mean that the progression circuit holes in Dells and Weber IDFs are better than in Weber IDAs which makes them more "streetable"

regds
David

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aussie1

Discussion Starter · #6 · Oct 6, 2006

Fastorq said:
The DellOrto TriJets are no longer available as new carbs. (The trijet circuit is actually cast in to all DellOrto bodies but only ever used in the 48mm carbs.)
Interestingly some early model IDF webers had a similar enrichment circuit but instead of a passageway in the carb body with a screwed in jet in the base of the float chamber , the Webers had a brass capillery tube reaching down into the bottom of the float chamber: but it did the same job.

The "extra" enrichment circuit doesnt actually make the trijet carbs more streetable but what it does is deliver an additional charge of fuel down into the throat of the carb at high RPM s

Both the Weber version and the DellOrto version work on the basic physics principle , that as you accellerate, the creation of the low pressure area which causes the carb to operate , moves upward .

As the Trijets capillery extends up even further than the aux vent fuel inlet it allows even more fuel to be introduced at the top end ie at high RPMs.

Dells vs Webers ??? up to 48mm size carbs most people would agree that Dells are better than Webers (you would expect that as the Dells are copied from the Webers and slightly improved.)
When you get to 48mm carbs on a large displacement engine my preference would be 48 mm IDF Webers

Ive got a set of DellOrto TriJets that were on an imported race car ,
(The red car that Ant used to race) the Dells were changed to Weber IDAs but apparently they made almost no difference !

So it sounds really that on the 48mm carbs it is down to personnel preference and condition of the carbs themselves. Out of interest why do you prefer the webbers? Is it for better perfomance or for improved 'streetability'?

The webbers i am looking at are relatively new - will they still have the extra enrichment circuit and how does the new stuff compare to older carbs?

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l.a.r.d

· #7 · Oct 6, 2006

i have some turbo spec 48 drla,s for sale and i also have some genuine 48mm italian idf,s for sale as well fully rebuilt and mint condition with no miles on them from that man above mr fastorque. contact me if you interested and speak to david (above ) fastorque for specs and condition, all the best Lee .

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Jay Aldred

· #8 · Oct 6, 2006

David,
How are you. I can see that carbs still get you going

BTW. sorry I didn`t get time to get back on the exhaust. Mine is totally welded, expansion rates on stainlesss allows this without cracks, slip joints are out on a turbo motor.

Take care my friend.

J..

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Fastorq

· #9 · Oct 7, 2006

l.a.r.d said:
i have some turbo spec 48 drla,s for sale and i also have some genuine 48mm italian idf,s for sale as well fully rebuilt and mint condition with no miles on them from that man above mr fastorque. contact me if you interested and speak to david (above ) fastorque for specs and condition, all the best Lee .

I rebuilt both of these sets of carbs for Lee and can vouch for them working perfectly as well as looking brand new.

The Turbo 48mm Dells (not tri Jets) have been precision machined on the inside of the spindle bosses to take "o" rings and retaining cages.
The 48 IDF Webers have the cam operated accelerator pump just like Weber IDAs also the Webers got new spring loaded diaphragms and a couple of new bearings.

Regds
David

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Fastorq

· #10 · Oct 7, 2006

Jay Aldred said:
David,
How are you. I can see that carbs still get you going

BTW. sorry I didn`t get time to get back on the exhaust. Mine is totally welded, expansion rates on stainlesss allows this without cracks, slip joints are out on a turbo motor.

Take care my friend.

J..

Hi Jay ,

Looks like I'm having to buy the 46 x 38 CNC comp eliminators after all + hemi cutting and K-motion springs!
Super Flows are too much flycut to use.
Wave ByeBye to another £1500....

Regds
David

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Jay Aldred

· #11 · Oct 8, 2006

Fastorq said:
Hi Jay ,

Looks like I'm having to buy the 46 x 38 CNC comp eliminators after all + hemi cutting and K-motion springs!
Super Flows are too much flycut to use.
Wave ByeBye to another £1500....

Regds
David

Lovely head though, you won`t regret it. Somebody will by the SF for sure.

Don`t want scare you but once you have had all the port and valve work done its probably nearer 2.2k

Take care and well catch up soon.

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