FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: MattFC on June 06, 2016, 09:13:45 PM



Title: Twin carb questions
Post by: MattFC on June 06, 2016, 09:13:45 PM
Hi all, quick question re running twins. I have a rebuilt stock carby (23-105D) and if I wanted to run twins, does the second carby need to be exactly the same model or could a later one be used? Also, what changes need to be done as far as jetting goes, if any?
I'm just giving it a bit of thought at the moment as I have just bought a set of extractors and I also have a Cain manifold that has been collecting dust in the shed for a few years.
Finally, does anybody have a good carby lying around that they wouldn't mind swapping for a few dollars? The shop where I bought my last one closed down and there isn't really anywhere nearby that sells them.
Thanks!
Matt.


Title: Re: Twin carb questions
Post by: Harv on June 07, 2016, 06:44:43 AM
G'day Matt,

The short answer is no, the two carbs don't need to be exactly matched. It's nice to have the same number on the side of both carbs, but a clever bloke realises that most of the grey carbs components are identical.

The link below is to my Stromberg Guide - take a look at page 24 for the different grey motor carb specs:
http://forum.fefcholden.club/index.php?topic=20117.0

The carbs you are looking for are 23-105's, 23-3000 and 23-3001. The really significant differences are the power bypass jet (which you will probably change), and the main discharge jet (which you will probably not change). In short, you want a grey motor carb with the same main discharge jet as what you have (28-34).

This means you should be hunting for another 23-105 carb (23-105A, 23-105B, 23-105C or 23-105D). You then change main metering jets and power bypass jets to make them both the same, and to make them both smaller for the twin setup. I can help out with both the main metering jets and power bypass jets when you get to that stage.

I've probably got a spare 23-105 in my spare parts stash. I'm on the road for work at the moment though - give me a yell in about three weeks if you are still looking.

Cheers,
Harv


Title: Re: Twin carb questions
Post by: MattFC on June 07, 2016, 06:47:37 PM
That's brilliant Harv! :o
Some good reading there and I reckon i might have learnt a thing or two, cheers for that.
If I don't find something in the meantime, I'll definitely take you up on the offer, much appreciated.


Title: Re: Twin carb questions
Post by: mcl1959 on June 07, 2016, 09:03:36 PM
I've got a 23/105D for sale. Has not been run for a while, but I guess you would be doing a rebuild anyway. You can have it for $25 plus postage.

Regards.   Ken


Title: Re: Twin carb questions
Post by: MattFC on June 07, 2016, 10:24:00 PM
Excellent Ken, consider it sold. I'll PM you for details.