Blow Through Carbs?

martin · Post by **martin** » Mon Jun 18, 2001 10:49 am

What exactly needs done to dellorto carbs to convert for Blow-through, also who will do this, prefer in the UK but anywhere really?

effvee · Post by **effvee** » Mon Jun 18, 2001 1:12 pm

Hi, Martin the Dells 40s or 44s blow through will need the throttle shaft "o" ringed in some cases they have installed the "O" ring in the carbs body. The body is to thin for the mechining, so Jack of Jay Cee Enterprises 1(714) 848-9898 did mine, he cut a groove in the throotle shaft and installed a "o" ring. Next CB performance 1-(559) 733-8222 will sell you the turbo upgarde kit. Don't forget to also buy the turbo emulsion tubes from CB Performance, needle and seats, ect, just ask the questions "what is need to trubo my Dells". The two numbers will do the job. Now Jay Cee's only want the throttle shaft alone, but if you are not up to putting the carbs together talk to Jack he is the owner and he is very good. Hope this helps.

Moog · Post by **Moog** » Tue Jun 19, 2001 5:59 am

In the UK, go to EuroCarb Ltd (formerly called "Contact Developments") at http://www.dellorto.co.uk

They are the main Dell'Orto carb agent in the UK, and are a mine of knowledge - they ONLY do Dell'Orto carbs. They can supply the factory turbo rebuild kits. They supplied a set of new factory turbo carbs to one friend of mine, and a used pair of turbo carbs to another friend. They also have a different view on it to CB performance (i.e. don't bother with modulator rings and the other fancy stuff CB say you need - the factory turbo carb does not need these parts). They also did the turbo carbs for the TotalVW car.

John Maher has also done some work recently on installing the shaft seals for blow through installations - i think he did Moggy's carbs.

Matt Keene · Post by **Matt Keene** » Tue Jun 19, 2001 11:43 pm

Moog, how do the factory turbo carbs richen the mixture under boost? I am running factory turbo carbs that were purchased from John Maher a couple of years ago and they seem to be pretty similar to ordinary carbs (bar the rubber membrane gaskets and seals). For this reason I machined a set of modulator rings to CB spec just to be on the safe side. Now if I don't have to run these because of some other richening method specific to turbo carbs, then I can chuck the mod rings and really get the cfm flowing. Mnnnnnn, airflow, there's a thought... Do you have any more info on these carbs? Thanks.

Moog · Post by **Moog** » Wed Jun 20, 2001 7:30 am

Matt - I'm not sure how the turbo carbs work, but if you speak to Martin Rogers([email protected] - not the Martin who started this thread!) he might know. He is doing a turbo 2.4 type4 for his '51, has a pair of these carbs, and has had some long discussions with the guys at Contact Developments (as they were called). The TVW car didn't have modulator rings on them. My reasoning is that if the factory turbo carbs needed modulator rings, then they would have come from the factory with them fitted!

For my part, I haven't played with the turbo carbs - I've got injection for my turbo toy - so don't know a great deal about them.

Whereabouts in Sussex are you? Martin is in East Preston, over near Rustington, and I am in Upper Beeding, just north of Shoreham.

[This message has been edited by Moog (edited 06-20-2001).]

martin · Post by **martin** » Wed Jun 20, 2001 1:22 pm

from what i've read turbo carbs enrich under boost by using turbo emulsion tubes

Matt Keene · Post by **Matt Keene** » Thu Jun 21, 2001 11:52 pm

I've checked the emulsion tubes on my turbo spec Dell's and they seem to be standard spec tubes. The turbo ones CB sells have very few holes unlike mine. Modulator rings do however work. I can cruise at stoich, fast drive at 12.5 and balls out 12 psi at 11.5 :1. I might try my setup without the modulator rings and check my A/F ratio to see what happens...steady on the throttle, mind...