Differences in Dellortos?

[Grewham]

Hi, i have 2 pairs of good nick Dellortos and just wondered which pair was the best to keep as there are sutle differences, any help much appreciated
cheers Gra

[types26/36]

I have never seen a screw like that covering the progression holes, normally there is a brass screw as your other picture.
Is that type of screw on the other choke? or on any matching carbs? is there a letter after the DHLA on the carb body?

[worzel]

Hi Brian

The cross headed screw seems to be common on the later carbs- probably cheaper than the usual brass plug!

John

[worzel]

Hi Grewham

I sent you a pm yesterday- thinking later- both types of carb might well be the later design! Check the idle screws- if they are recessed they'll be the later design- if they sit proud of the carb body and the spring underneath is visible you've got the earlier type.

John

[terryp]

I'd say both are the later types as they have the screw to remove for balancing with a manometer

Terry

[Grewham]

Thanks for all the feed back, heres a pic of the two carbs with the odd philips head screws.

cheers Gra

[bill308]

Brian asked if there was a letter following the DLH 40 number and hasn't gotten an answer. This letter, or the lack of one, tells a lot about the specific carb.

The early carbs had no letter, but were highly tunable and had 3-progression holes. Suffix letters C, D, and E were later versions, yet still fully tunable and typically offered up to 5-progression holes and probably an air balance circuit. Later letters were emission carbs and are probably not suitable for Lotus applications.

Bill

[Grewham]

Sorry for delay in answering this question, both sets seem to have an L after the DHLA, regards Gra

[bill308]

Hi Grewham,

A quick look at my Dellorto book indicates the DHLA 40L was fitted to several Alpha Romeo's, specifically, Alfetta 1.6 Berlina (3 series), Alfetta 1.8-2.0 Berlina (3 series), Alfetta 1.8-2.0 Berlina (3 series)(esp.), and also the Autodelta Turbo Guiletto 2000.

My book doesn't show Elan, Europa, or Seven applications, but these were likely no suffix DHLA 40's.

Later Lotus engines (2.0-2.2 liter) used mostly suffix E carbs, with an H used on the 2.0 turbo motor and an M used on the Turbo America.

The last time I checked, DHLA 40's, 40 E's, and 40 H's were still available new. If it were me, I would go for the no suffix or E carbs.

I'd also like to correct a typo in my previous post where I typed DLH and it should have been DHLA.

I hope this helps.

Bil

[alaric]

Hi. I have the 40DHLA with no suffix, on a car that was manufactured in '72. Both of mine look like your left hand picture, but with the bypass screw not fitted - there's a hole for the screw but it's not drilled through so far as I can tell. I've just received a rebuild kit in the post from EuroCarbs, and their instructions mentions balancing the airflow with the bypass screw. So this would never have been possible with my carbs. I recall mine only have the three progression holes from the jets, and this gives a sharper throttle response compared to the 5 progression holes which give better economy. At least that's what I read.

How do you balance the barrels within one carb if you don't have the bypass screw? I guess it's down to engineering tolerancing and making sure the butterfly spindles are not too worn.

I just found a pic of my carbs in my archive:

Shiny carb

Sean.