Tiny Tim Posted October 3, 2005 Share Posted October 3, 2005 Before everybody groans about yet another Weber post I have trawled through search for the last hour and have still not really found an answer to my question. So here goes, Further to a recent posting about idling on my carbs I have checked the jet sizes which are as follows: Choke 38 Main Jet ?15, ?25, 135 and ??5. (Difficult to read due to somebody having taken a file to the face where the numbers are stamped). Emulsion tube F16 Air corrector 165 on three and 155 on the other?? Idle 60F8 Pump 40 From my search it would appear that the Choke, Emulsion tube, Idle and Pump are probably about right. However I am obviously concerned about the main jets appearing to be a different size and why the numbers have been partly filed off?? I am also concerned about having one different air corrector size. This could be a genuine mistake as the stamp is quite difficult to read and the middle '5' could easily be mistaken for a '6'. From other searches I have seen the following recomended: (for 38 chokes) Main jet 150 Air corrector 180 Should I consider buying some new main and air corrector jets in the above sizes? What affect (+/-)might I see by going up in both main jet and air corrector size? Thanks for your help Tim Link to comment Share on other sites More sharing options...
EFA Posted October 3, 2005 Share Posted October 3, 2005 40mm chokes are a bit large for a std XE. 38's will much improve drivability and snap throttle low down, as 38's cause the induction to stall. Edited by - EFA on 4 Oct 2005 10:25:55 Link to comment Share on other sites More sharing options...
Graham Perry Posted October 4, 2005 Share Posted October 4, 2005 Filing the numbers off is not unusual. Often the rolling road operator will not have a jet of every required size in stock but they do carry a set of precision drills and will drill out a smaller jet to exactly the required size. To avoid future confusion they then file off the number of the jet so they know its not standard when they next look at the car. Roger King did exactly this on mine and another operator did the same some year prior to that. What this implies is that the carbs have at some time been set up on the rollers Edited by - Graham Perry on 4 Oct 2005 07:31:57 Link to comment Share on other sites More sharing options...
Gambo Posted October 4, 2005 Share Posted October 4, 2005 My Hpc came with 40mm chokes. Swapped them to 38mm as a number of people said 40mm was too big. never found any problems with the lower end of the throttle. if you want i'll check what jets and tube are in mine tonight, they are still in the garage. RED 2.0 HPC now on throttle bodies Link to comment Share on other sites More sharing options...
stevefoster Posted October 4, 2005 Share Posted October 4, 2005 Had 40mm, tried 38mm (was little difference to be honest, but perhaps I never got it 100% right on the idle jets, those recommended never worked that well and I didn't have the time/money for RR sessions). Went back to the 40mm for track work. I'll check what my mains were. The rest seems similar to what I had. Hants (north) / Berkshire club here Area meeting pics here My Racing here Edited by - stevefoster on 4 Oct 2005 09:47:51 Link to comment Share on other sites More sharing options...
EFA Posted October 4, 2005 Share Posted October 4, 2005 Sorry, I meant 38's over 40's rather than 38's over 36's. It was a long time (11years) ago that I ditched carbs in favour of TBs! I went down to 38's when I sprinted my car - this very much improved the pickup if you got caught off cam on tight circuits/hills. Edited by - EFA on 4 Oct 2005 10:25:41 Link to comment Share on other sites More sharing options...
ian balson Posted October 4, 2005 Share Posted October 4, 2005 Tim, I fitted the setup recommended by Roger King, and this has worked well, better on part throttle opening, better progression and a better response to flooring the throttle. It's probably lost a little at the top end compared to the old setup, but that was the only place the old setup was any good! Choke = 38mm Main = 155 Air = 170 Slow Running = 60F8 Pump = 35 or 40 (I went for the 35) Float = 12-13mm, 8mm closed. Are you going to the West Hants meet tonight? Rgds Ian Link to comment Share on other sites More sharing options...
Graham Perry Posted October 4, 2005 Share Posted October 4, 2005 Attached is an intesting previous thread on this with lots of info from Roger King. It starts off talking about 48's but most of it is about 45's on Vauxhalls here Some of it may be useful Link to comment Share on other sites More sharing options...
Tiny Tim Posted October 4, 2005 Author Share Posted October 4, 2005 Thanks for all the response. Gambo & Steve if you can let me know what you have used I would certainly be interested. (Gambo I have emailed you re your DTA ignition unit) Ian, thanks for your jet sizes. I don't normally go to the West Hants but I would very interested in meeting up you to discuss 'Sevens'. I actually live in Weymouth but work in Poole and occasionally bring the car into work. Do you set up your carbs yourself? Have you gone for 3D ignition yet? Tim Link to comment Share on other sites More sharing options...
Neill Anderson Posted October 5, 2005 Share Posted October 5, 2005 My car allegedly has a set of "mild hydraulic" cam and has tidy looking 45's. They appear to have the following: 40mm chokes I think Idle jets 50F6 Mains 170 Air corrector 200 Emulsion tubes F16 "Some jet" 85F9 (Not sure which jet this was when I cleaned the carbs) I can get a good idle, seems perhaps a touch lean at the top end but has a bad progression issue off light throttle openings below about 3000rpm. I think it is an issue between the progression holes, float heights and the rather excessive pump enrichment. When cold it can be tricky to catch initially (and easily flooded) but then runs very sweetly until it gets a little warmth and then you get the flat progression spot. I think the 2D ignition also helps annoy things, esp the lack of part throttle advance Hope this helps Neill Carbs will be for sale soon as I am building up an injection collection! New 7 Owner 1996 VX 2.0 Link to comment Share on other sites More sharing options...
Tiny Tim Posted January 3, 2006 Author Share Posted January 3, 2006 Edited 22:26 3/1/06 (posted reply to wrong thread!) Edited by - Tiny Tim on 3 Jan 2006 22:30:08 Link to comment Share on other sites More sharing options...
The Don Posted June 10, 2006 Share Posted June 10, 2006 To update the knowledge bank I've just had Neill's old car into T&M in Colchester and Ray (top Weber man) has changed the carb setup to: Chokes: 38mm Main jets: 155 Air corrector: 180 Emulsion tubes: F16 Idle jets: 60F8 Intake & discharge valve (the 'some jets' above): 85F9 Driveability is much improved - pickup from low revs is smoother and the problem of severe stuttering (over-lean) when returning to part-throttle after hard acceleration has been cured Not happy idling at less than 1200 rpm. Power is just under 200bhp (with QED 42H cams). Edited by - The Don on 10 Jun 2006 01:34:12 Link to comment Share on other sites More sharing options...
Don Cook Posted June 10, 2006 Share Posted June 10, 2006 Have a look here http://www.blatchat.com/T.asp?id=37149 Link to comment Share on other sites More sharing options...
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