Weber DCNF carbs
Discussion
I am considering replacing the two SU HD6 carbs on my Daimler 2.5 V8 with four Weber DCNF 40s. But before I shell out a redicioulous amount of my hard earned I need to know if four DCNFs will actually fit the rather small Daimler V8. The port spacing is 95mm even between the four inlet ports.
So does anyone have a DCNF they can measure or know the following measurments;
1. Overall height from base to top of carb without any extension/trumpets?
2. Overall width
3. Overall length
4. Length from center bore to both front and backside.
And the reason for chosing the DCNFs is that they supposedly are the smallest dual barrel carbs. Smaller than both the IDF and Dellorto DRLA. Oh and the fit across the V instead of along it.
So does anyone have a DCNF they can measure or know the following measurments;
1. Overall height from base to top of carb without any extension/trumpets?
2. Overall width
3. Overall length
4. Length from center bore to both front and backside.
And the reason for chosing the DCNFs is that they supposedly are the smallest dual barrel carbs. Smaller than both the IDF and Dellorto DRLA. Oh and the fit across the V instead of along it.
Hi there, I had a look in the shed and have a 36DCNVA lying around which I measured, It is similar to this one:
http://commons.wikimedia.org/wiki/File:Matra_Muren...
Only the choke is different from a 36 DCNF. Both these carbs are used in a twin set up on Simca/Talbot/Matra's and can be bought for little money (since Bagheera's are scrapped rather quickly, and Murena's use these carbs as a quick upgrade). For a 2.5 Daimler I would not go to 40, but consider 36 as a max. There are various venturi's you can play with, from memory the Bagheera uses 28mm and the Murena's I converted mostly like 29mm since they are 1600 instead of 1.2-1.4 litres of the Bagheera. So the standard Bagheera ones would be a good starting point I would think for your V8.
Measured dimensions of the 36DCNVA are: 119 mm height (126 mm if choke flaps are fully open, they then stick out a bit).
Overall width 140mm, without the fuel inlet extension (approx. 160mm with). You have to add approx. 45 mm for the throttle lever in between the carbs.
106 mm body depth (perpendicular to the throttle shafts), and this value is 119 mm if you include the adjustment screws length.
60 mm from front to centre bore, 46 from centre bore to rear (which is the side with the adjustment screws)
Hope this helps, good luck, will look nice (better than motorcycle carbs, which might be another option but I think dcnf's will have a better initial throttle characteristic for car use)!
Oh, and since we're all TVR classic fans over here, you can have mine for free so you can trial fit them, easier than working with only dimensions. You can also use it to think of your preferred manifold solution.
http://commons.wikimedia.org/wiki/File:Matra_Muren...
Only the choke is different from a 36 DCNF. Both these carbs are used in a twin set up on Simca/Talbot/Matra's and can be bought for little money (since Bagheera's are scrapped rather quickly, and Murena's use these carbs as a quick upgrade). For a 2.5 Daimler I would not go to 40, but consider 36 as a max. There are various venturi's you can play with, from memory the Bagheera uses 28mm and the Murena's I converted mostly like 29mm since they are 1600 instead of 1.2-1.4 litres of the Bagheera. So the standard Bagheera ones would be a good starting point I would think for your V8.
Measured dimensions of the 36DCNVA are: 119 mm height (126 mm if choke flaps are fully open, they then stick out a bit).
Overall width 140mm, without the fuel inlet extension (approx. 160mm with). You have to add approx. 45 mm for the throttle lever in between the carbs.
106 mm body depth (perpendicular to the throttle shafts), and this value is 119 mm if you include the adjustment screws length.
60 mm from front to centre bore, 46 from centre bore to rear (which is the side with the adjustment screws)
Hope this helps, good luck, will look nice (better than motorcycle carbs, which might be another option but I think dcnf's will have a better initial throttle characteristic for car use)!
Oh, and since we're all TVR classic fans over here, you can have mine for free so you can trial fit them, easier than working with only dimensions. You can also use it to think of your preferred manifold solution.
Edited by ephemera on Thursday 11th December 08:07
If you have access to some scaleable software, approximating dimensions should be fairly straightforward. That's a Maserati V6 from a Citroen SM. Import the pic into a drawing, scale, dimension, and go. If you can't do it, I can help.
It sounds like a worthwhile adventure, but where are you getting a manifold from?
Best,
B.
Top picture of the mating faces seems like a DCOE to me, isn't it?
http://www.poustusa.com/weber_carb_pages/tuning_we...
(bottom of page)
http://www.poustusa.com/weber_carb_pages/tuning_we...
(bottom of page)
Slow M said:
If you have access to some scaleable software, approximating dimensions should be fairly straightforward. That's a Maserati V6 from a Citroen SM. Import the pic into a drawing, scale, dimension, and go. If you can't do it, I can help.
It sounds like a worthwhile adventure, but where are you getting a manifold from?
Best,
B.
Top pic is as Ephemera says DCOE/IDF. DCNF is Square 48x96mm as used by Jenvey for the TB - http://www.jenvey.co.uk/home/twin-throttle-bodies/...
I will try to scale the picture, but do the SM use 36/40/42 DNCFs?
Thanks to Slow M and Ephemera I have bben able to make this rendering of a DCNF40 carb ontop of a Daimler V8. I also found a side sectional drawing and have indicated the top of the DCNF in comparrison to the original SU.
In the side view you can also see that the rearmost inlet will place the rearmost carb where the distributor is. The dynamo will have to be changed or moved aswell.
In the side view you can also see that the rearmost inlet will place the rearmost carb where the distributor is. The dynamo will have to be changed or moved aswell.
What performance modifications have been planned or undertaken? I gave away my Weber sizing chart, but on a guess, 4 40s may be a bit much, on a stock 2.5 liter V8.
If you have no desire to sqeeze some more power out of this engine, than the kindly folks at Jaguar/Daimler did, these are overkill.
You could choke them down, but I don't know, how good the signal would be. It's been a while, since I've educated myself, on this topic.
Anybody have a sizing calculator/chart handy?
Best,
B.
If you have no desire to sqeeze some more power out of this engine, than the kindly folks at Jaguar/Daimler did, these are overkill.
You could choke them down, but I don't know, how good the signal would be. It's been a while, since I've educated myself, on this topic.
Anybody have a sizing calculator/chart handy?
Best,
B.
What performance modifications have been planned or undertaken? I gave away my Weber sizing chart, but on a guess, 4 40s may be a bit much, on a stock 2.5 liter V8.
If you have no desire to sqeeze some more power out of this engine, than the kindly folks at Jaguar/Daimler did, these are overkill.
You could choke them down, but I don't know, how good the signal would be. It's been a while, since I've educated myself, on this topic.
Anybody have a sizing calculator/chart handy?
Best,
B.
If you have no desire to sqeeze some more power out of this engine, than the kindly folks at Jaguar/Daimler did, these are overkill.
You could choke them down, but I don't know, how good the signal would be. It's been a while, since I've educated myself, on this topic.
Anybody have a sizing calculator/chart handy?
Best,
B.
That's impressive. I'd love to know how to use 3d software properly. I've tried simpler programs like Sketch up etc. but have had no luck. So I have ended up trying to find parts that are pre-made that can be cobbled together to make what I need. However if you really wouldn't mind I might ask for some help when I have gotten a bit further in my planning.
Just received a pair of 40DCNFs from a MG Maestro I won on Ebay. Not quite correct as the idle set screws aren't angled like the 13-versions so will be tricky to get at when the carbs are placed after one another. Slight issue is that the center to center dimension for the throats will need to be 115-120mm and the port spacing on the heads is 95mm. Also need to somehow step the throats down from 40mm to 29mm at the heads.
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