Lotus Elan and Lotus Elan Plus 2 Forums

Due to concerns about the new Spanish manufactured Weber carbs I have purchased a pair of rebuilt Italian carbs. They look very good but on close inspection I notice that one of the carbs has 2 transition holes in each throat and the other has 3. I would like to know if this will have any effect on the running of the carbs before I install them on the engine.

Regards

Andy

Hi Andy --do you mean the holes in the butterfly s ??? I have only ever seen 2 --but 3 may remove the ;flat spot' on acceleration ----ed

The progression mixture as you come off idle to when the main jet comes in and is dominant will vary between the 2 carbs if one has 2 progression holes and the other has three if all the other settings are the same. It may not however be noticeable and in a compettion car you rarely if ever run in this region anyhow.

I would give it a go and if any problems then you can always drill a matching third hole in the carb that has just 2.

cheers
Rohan

Thanks for the replies, Webcon has told my engine builder the 3 holes were used on Alfa engines but it should not be a problem with a race car so we will see how it performs on the dyno and if required drill the extra hole to match the other carb just to balance them up.

regards

andy

Andy, your concerns about the Spanish built webers are valid. I have a set of 151 (Spanish built) 40s and they came with three progression holes. It took a long time to get them to work properly but I like them better now than the 18s I had on the car previously.

Greg Z
'72 Sprint

Greg

My biggest concern was the number of people who have told me they have had underbonnet fires when using the new spanish manufactured 45s
regards

Andy