CB Performance update kit for Dellortoes

[jakriz]

G'day guys,
I was wondering if any of u have had any used the CB performance update kit in your Dellortoes. I have the chance to grab a kit which is quite rare downunder, but before I fork out the money , I'd like to know the benefits. I currently run 45mm Dells which are perfect, they pull from 1500rpm in 4th gear, so why would I update? is there more power?
I used to have an article on the kit in an old VW trends magazine but it's long gone & the article is on the CB Performance website but is too small to read.
Have any of u guys used this update kit?
regards
Jak

http://www.clubvw.org.au/images/goulburn0002.jpg

[Alex]

Hi Jak,

I believe that the kit is like the Weber rebuilt kits with all the parts that might wear like gaskets and so one. Depending on how old and used your carbs are I would think that it is a good idea to go thru the carbs and replace those parts.
It should help to tune the carbs better....but again...that depends on how old your carbs and in which condition they are in.

This is my opinion on it......

Alex

[jakriz]

G'day Alex,
I've had the carbs for about 6 years now & put a rebuild kit through them about 4 years ago just for the hell of it. They drive beautifully. I'm sure that I read something about horizontal discharge tubes were part of the CB kit & it gave more HP.
regards
Jak

[bren]

yeah the cb update kit is not a rebuild kit.. it replaces the main and auxillary venturis with a solid one piece venturi and at the top sits a horizointal discharge tube.... idle jet stack is also plugged somehow.. gets it air from elsewhere... the thing i dont understand though is why its only available for 40's and 45's .. i wonder if its easily fitted into 36's or 48's though? i also am not sure if different venturi and jet sizes are available to suit your application or if you only get what youre given??

[Alex]

Thanks for the info guys...I did not know.

Alex

[bren]

this is the contents of the kit... i will try and find out more...
http://www.cbperformance.com/catalogimages/7345.jpg

[jakriz]

Yeh thats the one Bren, I suppose u wouldn't have the VW trends issue that showed the dyno graph showing the imporovement over stock?
regards
Jak

[bren]

nah, sorry mate.. i only manage to get about 5 or 6 copies of trends each year, and i must have missed that issue.. have you tried getting touch with the trends editorial staff.. they may be able to scan a copy of the page?!

[jakriz]

good thinking Bren, I'll try asking them.
regards
Jak

[kdanie]

Jak,
I think you would make more power with the update kit due to less restriction to the air flow. How much I don't know.
I have spent quite a bit of time on my Dellortos, rebuilding them and working on air flow. I noticed that there are many edges where the different parts fit together that are in the air flow and will disrupt the flow. I spent a couple of hours smoothing the casting flash on the booster vents and slimming down the ends where they mount. I used an abrasive flap wheel to match the carb body to the top plate and then to the velocity stacks. I also polished the venturi and smoothed both ends. I think it will improve the air flow considerably for only the cost of the abrasive tool and some time. Something to think about.
With out testing before and after on a flow bench there is no way to be sure though. I have a pair of modified 40mm dells and a stock 40mm dell....when I get a chance I will get them into the local head shop and see how each flows. I have a modified 45mm dell on my office desk, I am still looking for a good deal on another 45s (the dells with the "s" after the number have vacume ports for use with a vacume advance distributor).
ken