Dellorto Experts - Check me out Options

[bandjoey]

Car has a 1.8 that was rebuilt before I bought the car. The PO doesn't know what was done or size of the rebuild...he just paid the bill to make it run.

It has DRLA carbs. It came with a Tomlinson Tech book, and in the back of the book is written:
140 Main
9164 2
60 Idle
34Mm Main Venturi

I bought a Pierburg rotary fuel pump from a local shop and was told it didn't need a pressure regulator at the time - it had an internal regulator that put out 3.5lbs. Can anyone confirm this or do I need to get a fuel pressure gauge to test the pressure? If I need a regulator, what's the right one to get.

The motor runs strong and pulls with torque from 3000 up to 5000. Occasionally, I'll hear a small single pop from the carb when I step on the pedal, but it's not often.

However, my gas mileage stinks, and when I start the car after it's been sitting for a few days, there's the distinctive smell of the old lawnmower starting up - that pukey gas smell out the exhaust. Within a couple of minutes, the smell is gone.

I'm going to go through the entire trouble shooting process this weekend from the book. Valves, timing, sync the carbs, and adjust the mixture etc.

??? Exactly what do the numbers above mean and mean to me? Are these carbs a good size for a 1.8ish motor? Suggestions of what to look for with bad gas mileage? Any DFW Dellorto experts that want to supervise? Thanks All.

(yeah Clay, I'm going to work on the FI back on this winter (IMG:style_emoticons/default/smash.gif) )

[anderssj]

Hi Bill,

FWIW . . .

I'm running a pair of Dellorto DRLA 40, purchased at CB Performance in 1982. They originally came with the venturis and jets as you listed, but I made a few changes as follows:

30mm venturi (down-sized from original CB setting @ 34mm)
55 idle jet (down-sized from original CB setting @ 60)
135 main jet (down-sized from original CB setting @ 140)
180 air correction jet (original CB setting)
9164-2 emulsion tube (original CB setting)
35 pump jets (I think--but they're the original CB setting)

I have a fuel pressure regulator on it, but can't remember the brand name. I think it's set for 3.25 or 3.5 psi.

The engine is a 73 2.0 (GA) rebuilt with a euro PC set and an Elgin cam (7008-4). It's running a re-curved Bosch 050 distributor w/ about 12* to 13* initial advance with 30* full advance (unfortunately I've lost the spec's on the recurve, but am planning on going back and figuring it out soon). We put it together back in 1981.

I made the changes to carbs as they were running rich when I first installed them. Also, it seemed that the venturis were a little too large for my displacement (stock 2L (1973cc?)).

The car now has 234+K miles (turned 234,567 miles last Sunday), over 124K with the Dells.

I've got some tech articles I can e-mail to you if you send me a PM w/your address.

Hope this helps.

Best,

Steve A-