I have read quite a few books on webers and done a fair bit of weber tuning. Although the choke sizes are the same a 45DCOE with a 36mm choke will flow more air than a 40DCOE with a 36mm choke. As for what size carb to use, you need to determine approx what size choke you will be needing. I would use 40DCOEs for a 34mm or smaller choke and 45DCOE for >34mm. Using the bigger 45DCOE means the throat will taper down more (i.e. from 45->36mm instead of 40->36mm) giving you a stronger vacuum signal and better fuel atomisation at light loads.
Cheers, Chris Howard [EMAIL PROTECTED] http://turbovan.com/ P.S. my L16 came with 45DCOEs with 30mm chokes!... Now running 36mm after trying 34,36,38,40 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] On Behalf Of Terry Rudd > Sent: Monday, 4 February 2002 11:01 PM > To: [EMAIL PROTECTED] > Subject: RE: webers > > > I agree with Chris on this one, i.e. that webers without > chokes they would > run like sh*t especially in peak hour traffic but they just > may run well > when the cam comes on song on a track. It wouldn't be much > different to > hilborne injection which basically is a metered spray of fuel > squirted into > an air stream, vacuum and pulse theory seems to be ignored by > that system > also. > > Many years ago we actually fitted a set of twin 40's to my > L16 engine, same > everything as my 45's and the power was down by over 10% > (dyno measured), I > know one experience is inconclusive but no one seemed > surprised at the time > nor could the experts of the day offer any plausible > explanation of why this > is so - seems time doesn't offer any better explanation. > > regards > Terry > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of Chris Howard > Sent: Monday, 4 February 2002 8:19 PM > To: [EMAIL PROTECTED] > Subject: RE: webers > > > So how does the carb get a vacuum signal if there is no > choke?? This is > the principle of a carburettor... The inlet tract narrows which > increases air velocity, creates a low pressure area which > sucks the fuel > in thru the jets. I would be very surprised if a Weber will > run properly > with no chokes at all. I would love to see a pic down the > throat of your > working carbs with no chokes. > > Cheers, > > Chris > > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
