Lotus Elan

Balancing Dellorto DHLA 40s

PostPost by: handi_andi » Mon Feb 25, 2008 6:35 pm

Hiya
I tried to balance my Dellorto carbs today but it appears I have an inbalance between all four cylinders, hence I would like to balnce the two pairs and then balnce the two carbs to each other using the normal balancing screw. I had a look at http://home.comcast.net/~jrkengr2/html/ ... ne_ii.html which seems quite helpful and makes reference to a bleed screw on each choke to allow all four to be individuallly balanced. I can find the hole where the bleed screw should be but the bottom of the hole is blank. It could be that there is some sort of anti-interference sleeve in there or it could be that the set of carbs I have weren't fitted with the bleed screw and one is meant to balance each one in a different way. Can anyone shed any light please?

I did notice that adjusting the mixture screw seemed to affect the amount of air being drawn in, which surprised me to a certain extent. Would it therefore be sensible to set the mixtures via a colourtune, then balance the carbs and then go ba through the loop again as necessary?

Thanks

Andrew
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PostPost by: alaric » Mon Feb 25, 2008 8:27 pm

Andrew,

I bought a 4 column manometer from Eurocarb off ebay. It's supplied with 4 little adaptors that allow you to screw into the 4 barrels of the Dellortos in parallel and compare the pressure directly without impeding the air flow. It turns carb balancing into a 2 minute job. Worth every penny.

http://www.carbtune.com/

I also bought a book: I've just been hunting and cannot find it at the moment - I've posted the name etc of the book before so a search should give it to you. Following the book turned tuning the carbs into a pleasure. It presents a very methodical approach to getting the mixture and balance correct. Bet I've lent it to someone...

The book is:

"How to build and power tune Weber and Dellorto DCOE, DCO/SP & DHLA carburettors" from ebay. Author is Des Hammill. Published by Veloce. ISBN 1-903706-75-0.

Sean.
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PostPost by: handi_andi » Mon Feb 25, 2008 10:25 pm

Thanks for the recommendations, have just ordered both along with the equivalent book for ignition system tuning. So here is hoping the old girl will benefit even if my wallet doesn't! :lol:
Andrew
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