Weber question

[Ianashdown]

I have not been able to find what the numbers after the DCOE mean, can anyone explain the difference between a 40 DCOE 18 and a 40 DCOE 151?

Thank you,

Ian
SoCal

[StressCraxx]

Ian, I may be totally wrong, but I believe the suffix numbers are engineering revisions to the original design. I know there were distinct differences between the DCOE 18 and 31. The idle progression holes on the 31 were different and the method to retain the venturis was better than the spring clips. The 151 was a redesign that incorporated adjustable air bleeds for easier and more precise idle and slow running properties.

https://www.liquisearch.com/weber_carbu ... odel_codes

[Ianashdown]

It seems that Weber model variants are quite confusing!

It seems that 151’s may be a ‘slight’ improvement over the original 18’s. I’m not sure if one of my original carbs can be refurbished to an adequate standard, but I have a nice set of 151’s that I’m sure will function well and look the part.

At least I have a plan ‘B’!

Ian
SoCal

[2cams70]

"151"s are universal fit Webers supplied in a non vehicle OEM specific specification. 18's and 31's have been calibrated by Weber for Lotus in a vehicle OEM specification.

[Ianashdown]

Would it be reasonable to suggest that 151’s could be optimized for a TC on a Dyno, by someone who knows what they’re doing? Chances are the internals will not be ‘stock’ so even the original carbs would need tweaking.

Appreciate the input,

Ian
SoCal

[2cams70]

Would it be reasonable to suggest that 151’s could be optimized for a TC on a Dyno, by someone who knows what they’re doing?

Yes of course - getting it done a dyno is the best way.

[alanr]

Would it be reasonable to suggest that 151’s could be optimized for a TC on a Dyno, by someone who knows what they’re doing?

Yes of course - getting it done a dyno is the best way.

Always providing you can find someone who really know what they are doing with Weber carburettors and has boxes of the various jets on hand that will be required!
Far too many places with dyno's now only know about modern injection cars and mapping and know absolutely zero about carburettors.

Alan

[512BB]

I believe I am correct in stating that 151s started life being made in Italy, and reflect that in the casting quality, as well as having MADE IN ITALY on the top cover, before something, can't remember what, happened, and production moved to Spain, with the resultant MADE IN SPAIN being then applied to the top cover and a rather rougher casting, shall we say.

I know what I would rather have, and if anybody feels the same, I have a pair of new old stock Italian made 151s that I would part with.

Leslie

[Ianashdown]

Definitely agree on the ‘Made in Italy’ Vs ‘Made in Spain’! I have two pairs of Italian 151’s, one pair I’d like to sell to fund something in my restoration, the other I’ll keep in case the one of my original carbs is too far gone. I’ve seen the results that Mike Pierce can achieve with even really rough looking carbs to start with, so I’m hopeful I’ll be able to stick with the original 18’s.

I appreciate the depth of knowledge here! I’m sure over the next couple of years as I progress in my restoration I’ll have plenty of questions! I hope I can be a resource too.

Ian
SoCal

[mbell]

The number or TIPO is the variant of the carb, it specifies what car/engine the carb was built and tuned for from the factory. Tuning includes some changeable items like jets, needle valves but also so not changeable things like progression hole number and positions.

40 DCOE 151 are generic carb built as replacement for any 40 DCOE. They are all configured the same by the factory and are expected to be re-tuned on fitting. DCOE 151 also have a few "upgrades", these include air bleed adjustment for balance the two carb throats, air take off port for balancing, screws for holding the venturis and a different(better?) transition hole positions.

Generally DCOE 151 when reconfigured to Lotus setting work well on the twincam. Can't speak to Spanish v Italian but my Spanish built DCOE 151 are working well on my car.

[ajwheels]

I've got "Italian" 151's on my car and they work great....nice idle, nice transition to open throttle, no flat spots....and as mbell mentions, the "upgrades" of air bleed adjustment and air ports for balancing make set-up precise and clear when using a manometer device, such as a Carbtune.....if your car originally had the 18's, I can see the reasons for retaining them.....but always good to have a Plan B.....