Heya guys,

I'm just trying to sort out what I want to run on my A14 and was curious if anyone has, does are have experience in running twin weber 40 DCOM's? I know the pumper is a diaphragm setup, but is there a noticeable difference over the DCOE or the DHLA 40's? Are they physically all the same size as well?

Clay

G'day Clay,

There was a bloke from Malaysia that was running one. I'm pretty sure you'll need to build your own manifold as the bolt patterns differ as well as the barrel spacing (I'm unsure so you may want to check).

The sidedraft manifolds suit the Mikuni PHH, Weber DCOE and Dellorto DHLA style bolt pattern/barrel spacing.

Diaphragm pumps are a good thing though I reckon.

Chris

I think they share the same bolt pattern as an IDF but are sidedraft not downdraft. I have a Weber book here somewhere.... but maybe someone else would be better at clarifying....where's Benny he knows his webers?

Heya Chris,

Thats a great point, I didn't even think of that.

I got onto a couple of guys about the manifold spacing / bolt pattern and was told that they are all compatible.

"DCOM's will bolt on any standard side draft weber 40 DCOE carburettors manifold.uses all the same inner parts-jets/needles/seats/floats,,,as the former DCOE carbs.." "have the exact same dimensions as the weber 40 DCOE version"

Thats a comfort I guess. Just wondering how they perform on the A series.

Clay

Sorry I had it all wrong, I just spoke to a mate (about something else entirely but thought I'd ask him) and he insists the DCOM carb is the newer version/replacement to the DCOE.

The DCOM runs an improvised accelerator pump (diaphragm) system over the DCOE and they are apparently a better performing carb than the DCOE. The DCOE runs a piston pump format. The DCOM acc pump also features an adjustable rod for the pump.

Funnily enough this is why I like Mikuni's so much they have a reliable and accurate accelerator pump system WITH an adjustable pump rod. Accessible externally for fine-tuning of the fuel delivery volume of the pilot jets. The only thing I really like about webers (and that I'd like to see on the Mikuni's) is the roller bearings on the throttle shaft. But then again even these have been known to cease and hesitate. A handful of the webers I have seen have had hesitant throttle returns largely due to hesitant/old bearings.

So I guess they perform just as well if not better than a DCOE weber.

Sorry for the confusion.

mate, does DCOM have ported vacuum port? the one that should be connected to the dizzy..

I prefer bike carbs, lighter, cheaper and better runner spacings
to suit the A series head is possible and infinite length if
the room allows it to suit required performance.