Help needed with 1966 Fulvia S1 1.2 DHLB 32 Jetting and Settings

[lambretta69]

Hi Everyone, I have a pair of Dellorto DHLB 32 that I want to set up for my 1966 Fulvia S1 1.2. It's a stock engine and has an Abarth performance exhaust. I purchased the Omicron Fulvia Dell'Orto Carburetor Setting Manual but it's not specifically for my car so I'm hoping someone on this forum can help. If you have any experience with this, can you please let me know what sizes I would need to adjust for my car? Here are the specs for a DHLB 35. I can't find information for DHLB 32 anywhere. Thanks in advance -Rob.

Venturi 33 mm (obv too big for DHBL 32)
Main Jets 112 mm
Main emulsion 7772.4 or 7772.3
Main air correctors 200
Idle jets 45
Idle air correctors 120
Power jet 60
Starter jet 70
Pump jet 45
Fuel inlet 150
Float No. 1, 7298.1 10 grams, 13-13.5mm level

[marnix]

Hi. Included (I hope it works...) a document that gives all the details specific for DHLB carbs on the Fulvia.

[marnix]

Something additionally important for S1 cars without fuel return line and without fuel pressure regulator; and that was not in the document:

- the DHLB carburettors are extremely sensitive to too high fuel pressure. For S1 Fulvia cars without fuel return line and not equipped with a fuel pressure regulator it is almost mandatory to install a fuel pressure regulator. Especially with aftermarket fuel pumps that almost all give higher fuel pressure than the original FISPA pump.

Modern fuel pressure regulators are available, like the MALPASSI. They are available as a pressure regulator only, or with fuel filter element.

[lambretta69]

Thank you so much for sharing the document and for the additional information. It's exactly what I need and more. You are a lifesaver. Have a good one! Best, Rob

[marnix]

A special warning... it is written in the document, but I would like to specify it explicitely here.

The DHLB 32 (unlike the DHLB 35) was made in several vesions, not only for the Fulvia (Fiat, etc). The versions for other makes are NOT compatible with the Fulvia (even considering that they are configurable up to a certain level). I you intend to buy a DHLB 32 set for the Fulvia, you have to check if these are specifically the version for the Fulvia, and NOT for the other makes.

The DHLB 35 were made specifically for the Fulvia. But over time, some have been 'modified' for use on other car types, possibly making them now unsuitable to be used on the Fulvia.

[lambretta69]

Thanks for that. Do you happen to know what to makes them incompatible if not specifically made for a Fulvia? I believe the ones I purchased from Eurocarb were made for a Fiat 124.

[marnix]

Was afraid of that. DHLB 32 for other makes can stil be found, yes. DHLB 32 and 35 for the Fulvia are becoming extremely rare. NOS is almost impossible. Sometimes you can find used ones....

I need to check again on all the details for the differences and if it is downrifght impossible or can be done with quite some effort... and even more difficult, parts..., it has been quite a while since I tried to figure out.. In a way, you can yourself: look at the parts pictures for the Fulvia DHLB and compare with what you got...

It is maybe not impossible... but you certainly need some other parts, and parts for the DHLB are running out...

[lambretta69]

Thanks for checking further. I was planning on changing out the jetting, choke, banjos, balance levers, choke cable etc... basically everything. I have managed to track down the majority of these items already. I was thinking with all the correct sizes it would be be a viable solution to my carb troubles. I never thought that the carb couldn't be used if it fit and had the correct modifications. It would be good to know what will happen if I attempt this! Thanks, Rob