Jeff Stich
True Classic
Venturi vs. throat size
You're talking throat/barrel diameter (which is the "30" in 30DICA). The 23mm spec I noted is the venturi size, ie: where the barrel constricts inward about halfway down the barrel.
(NOTE: In the photo above, what they note as "Secondary Venturi" should be labeled instead as "Auxiliary Venturi". They likely have it labeled as it is because the photo depicts a single-barrel carb).
If you look on the front face of the carb, in the center between the barrels you'll see a small oval with the venturi sizes noted by cast-in numbers of "23-23" on the 30DICA & "23-21" on the 30DIC. This represents the 23mm secondary venturi & 23mm (or 21mm) primary venturi sizes.
I've never had a problem with the needle & seat wearing prematurely from this, so I can't really comment on it. Ditto on an "overheated" fuel supply.
Care to take a sec and clarify? I measured both throats on my DICA...and both measured 32 on the top plate, and 30 in the body. Mic'd my other (2) DICA's and each measured the same as above. I am having trouble figuring out where the "23mm/23mm venturi (vs. 23/21 of the 30DIC)" dimensions are coming from. I figure I must be measuring the wrong area?
You're talking throat/barrel diameter (which is the "30" in 30DICA). The 23mm spec I noted is the venturi size, ie: where the barrel constricts inward about halfway down the barrel.
(NOTE: In the photo above, what they note as "Secondary Venturi" should be labeled instead as "Auxiliary Venturi". They likely have it labeled as it is because the photo depicts a single-barrel carb).
If you look on the front face of the carb, in the center between the barrels you'll see a small oval with the venturi sizes noted by cast-in numbers of "23-23" on the 30DICA & "23-21" on the 30DIC. This represents the 23mm secondary venturi & 23mm (or 21mm) primary venturi sizes.
What's your thoughts on the fuel pump pressure fighting the float shutoff valve? I have often wondered about these carbs without the bypass must prematurely age the float shutoff valve?
I won't even mention the cooling aspect of a continuous flow system.
I've never had a problem with the needle & seat wearing prematurely from this, so I can't really comment on it. Ditto on an "overheated" fuel supply.