DCOE vrs DCNF Inlets

CnC79X19

CnC79X19

True Classic
Are the DCOE and DCNF fuel inlets the same and interchangable. Are the banjo bolts interchangable as well?
 
I know that the banjo bolt gaskets are interchangeable. I suspect the boots are interchangeable but have not confirmed that.
 
You might try contacting Pierce Manifolds since they carry both carbs and parts for them. You may find the answer on their web site.
 
"Fuel union(banjo) bolt for Weber DCNF carburettors, will fit all sizes from 34 / 36 / 40 / 42 / 44 milimeters.Will fit also Weber DCOE or DCO/SP but it is not original for this carburettors."
classicperformance-parts.com

WEBER DCNF CARBURETOR FUEL UNION BANJO BOLT - Classic Performance Parts

Classic Performance Parts - WEBER DCNF CARBURETOR FUEL UNION BANJO BOLT
classicperformance-parts.com classicperformance-parts.com


I guess they are all M12x1.5. But I do have some banjo bolts that are not the good thread for my DCOE. So they may be for another makes.
 
CnC79X19 said:
Are the DCOE and DCNF fuel inlets the same and interchangable. Are the banjo bolts interchangable as well?
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I just happen to have some parts lying on my desk. Both the DCNF and DCOE have the same threads. The shoulder that centers the inlet on the bolt is smaller on the DCNF bolt (see gasket size) so is not ideal to use it with the DCOE inlet. The DCOE bolt can be used however it is slightly longer so it bottoms out in the DCNF body without clamping the inlet to the carb body. This is without the gaskets installed. Clamp load can be achieved with the gaskets installed. I’ll likely shorten the bolts slightly to ensure a good clamp load is created.
1596493606688.png

1596493633398.png
 
Looks like there may be an extra step on the bottom of the DCOE bolt head. I bought what was labeled as DCOE gaskets from Pierce, but they fit the DCNF bolt perfectly. The small ID gasket goes toward the end of the DCNF bolt and the large ID one goes under the head just like the DCOE.
 
dllubin said:
Looks like there may be an extra step on the bottom of the DCOE bolt head. I bought what was labeled as DCOE gaskets from Pierce, but they fit the DCNF bolt perfectly. The small ID gasket goes toward the end of the DCNF bolt and the large ID one goes under the head just like the DCOE.
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The smaller ID gasket fits the DCNF bolt perfectly. The larger ID fits the DCOE bolt on the head side and the smaller ID fits the bolt size. So 2 small ID gaskets for the DCNF and one of each for the DCOE. However the DCOE fuel inlet fitting ID is a match for the shoulder on the DCOE bolt so it is centered and will be loose on the DCNF bolt. As you mentioned there is a second shoulder on the bolt that matched the smaller ID gasket so it could be assembled with 2 smaller ID gaskets however it would prevent the shoulder from centering the Inlet fitting.
 
My DCNF bolts require one large ID and one small ID gasket like the DCOE bolt you showed. Perhaps they changed the design. I bought my carbs new in 1980 when they were still made in Bologna. That was 40 years ago and with the manufacturing move, I would not be surprised if there have been changes.
 
dllubin said:
My DCNF bolts require one large ID and one small ID gasket like the DCOE bolt you showed. Perhaps they changed the design. I bought my carbs new in 1980 when they were still made in Bologna. That was 40 years ago and with the manufacturing move, I would not be surprised if there have been changes.
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Sounds like there are some different bolts available. The DCNF one I showed is from ~'90 from 42 DCNFs I bought from Al C back in the day. . The DCOE bolt was purchased recently (within a year or so) from carbparts.eu (Ebay store).
 
I did find a reasonably priced kit from the UK but that company isn't shipping internationally presently. I'm going to throw it out there one more time on the FS&W forum here and cross my fingers.
 
It seems Weber used components that differed slightly over the years, and from all of the various Weber manufacturing facilities around the world, for pretty much all of their carbs. As far as I've noticed they are all pretty much interchangeable provided they match the corresponding parts (e.g. the seals and fittings). Not sure if that helps any though, depending on what you have (or should I say don't have).
 
Brad Garska said:
I just happen to have some parts lying on my desk. Both the DCNF and DCOE have the same threads. The shoulder that centers the inlet on the bolt is smaller on the DCNF bolt (see gasket size) so is not ideal to use it with the DCOE inlet. The DCOE bolt can be used however it is slightly longer so it bottoms out in the DCNF body without clamping the inlet to the carb body. This is without the gaskets installed. Clamp load can be achieved with the gaskets installed. I’ll likely shorten the bolts slightly to ensure a good clamp load is created.
View attachment 35023
View attachment 35024
[/QUOTE
Click to expand...
Brad Garska said:
I just happen to have some parts lying on my desk. Both the DCNF and DCOE have the same threads. The shoulder that centers the inlet on the bolt is smaller on the DCNF bolt (see gasket size) so is not ideal to use it with the DCOE inlet. The DCOE bolt can be used however it is slightly longer so it bottoms out in the DCNF body without clamping the inlet to the carb body. This is without the gaskets installed. Clamp load can be achieved with the gaskets installed. I’ll likely shorten the bolts slightly to ensure a good clamp load is created.
View attachment 35023
View attachment 35024
Click to expand...
So if I'm reading and seeing it right Brad the difference in the two banjo bolts are the overall length, and mating rings on the heads? You mentioned that the pitch is the same on both but are the other dimensions equal? Bores, shoulder length etc? If this is the case and only a shortening of the DCOE banjo will suffice then why wouldn't this route work? Any others who care to comment are welcome
 
CnC79X19 said:
So if I'm reading and seeing it right Brad the difference in the two banjo bolts are the overall length, and mating rings on the heads? You mentioned that the pitch is the same on both but are the other dimensions equal? Bores, shoulder length etc? If this is the case and only a shortening of the DCOE banjo will suffice then why wouldn't this route work? Any others who care to comment are welcome
Click to expand...

Yes the DCOE bolts will work using the fuel line fittings shown. Regarding shortening the bolts, I would recommend checking the fit to ensure the bolt isn't bottoming out on your particular carbs. If it is then I would recommend shortening the bolts slightly ~1mm or so to ensure you have a good clamp load/seal.

Please see below for comparison. - Hopefully this clarifies the differences.
1596587931806.png
 
Brad Garska said:
Yes the DCOE bolts will work using the fuel line fittings shown. Regarding shortening the bolts, I would recommend checking the fit to ensure the bolt isn't bottoming out on your particular carbs. If it is then I would recommend shortening the bolts slightly ~1mm or so to ensure you have a good clamp load/seal.

Please see below for comparison. - Hopefully this clarifies the differences.
View attachment 35065
Click to expand...
Thank you so much Brad. This is a huge help. For curioysity's sake are you installing the kit you have on DCNF''s as well?
 
Great, that curiosity (spelled curioysity's in my post) makes me look like a complete low functioning moron. Please disregard that and assume it's simply from my big fingers and poor eyesight. Can't thank you enough here for the advice on the inlets and banjo bolts.
 
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