SENNA1 Posted July 12, 2011 Share Posted July 12, 2011 Hi guys, which weber jets are best for my engine?It's a 2.0S OHC.(e.g. weber 45's,40's,or 38's). Which twin webers i have to choose from these? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
lamchop77 Posted July 12, 2011 Share Posted July 12, 2011 Hi guys, which weber jets are best for my engine?It's a 2.0S OHC.(e.g. weber 45's,40's,or 38's). Which twin webers i have to choose from these? Thanks in advance. Go for the biggest, they can always be choked down. Chris Quote Link to comment Share on other sites More sharing options...
SENNA1 Posted July 12, 2011 Author Share Posted July 12, 2011 Go for the biggest, they can always be choked down. Chris Thanks for the reply Chris! But,what do you mean they can be choked down? In my situation,i already have 2 twin DCOE Weber 45's & i've been told that if i would replace them with 40's or 38's the engine performance would be much greater If that's the point,which parts do i have to replace from the existing carbs? Thanks again Quote Link to comment Share on other sites More sharing options...
lamchop77 Posted July 12, 2011 Share Posted July 12, 2011 (edited) Thanks for the reply Chris! But,what do you mean they can be choked down? In my situation,i already have 2 twin DCOE Weber 45's & i've been told that if i would replace them with 40's or 38's the engine performance would be much greater If that's the point,which parts do i have to replace from the existing carbs? Thanks again The side draught carbs have replaceable venturis in them. If you look into the carb towards the engine the hole that you see is the choke. So basically what you can have is a side draught 40 with 36 mm chokes say, but you can fit 36mm chokes into a 45 body. Jetted up they are the same carb as far as the engine knows as the same amount of fuel/air will be drawn in. With the 45's though you can fit bigger chokes so if you do tune up slightly you can open the carbs up to cope. Can't see how dropping a size is going to help as you will be restricting the engine. Guy's i autograssed with used to use the 2.0 OHC motors bored out to 2.1 and they were all running 45 or 48's. I needed carbs for my CIH race motor and rang up the rolling road guy for advice as i had the choice of 45 or 48's. The advice was "get the biggest as we can always choke them down, we can't go up though" Look on the internet there should be some images or diagrams of the parts in the webers. What state of tune is your engine at. If its a std motor with carbs bolted on then a smaller set of carbs may be better. If its at all cammed up then i would stick with 45's. I have a 2.0 CIH which has a shade under 160bhp and that runs on 40s that are bored out slightly further than they should be. When that was rolling roaded the guy said the carbs were on there absolute limit of delivering fuelling so i would need to move up a size if i did any more. Ford Pinto engines need 45's to run properly on mildly tuned motors as the ports are too large for the engine really, so head flow comes into the eqaution as well. HTH Chris Edited July 12, 2011 by lamchop77 Quote Link to comment Share on other sites More sharing options...
monzta Posted July 12, 2011 Share Posted July 12, 2011 I´ll agree with Chris on this. Whom ever told you that downsizing your carbs would give you better power don´t know what they are talking about. The bigger the carb, the more you´ll get. The downside to using big carb´s (say 45, 48 or even 50mm) is that the car will seem slow in the low rpm´s and won´t respond that well to throttle. A set of 40´s with 36 venturis (this is what most 40´s has) will give you a smooth ride and nice power. I would definatly go with the 45´s they will run great on that engine. Used to have 45´s on a 2,2 cih A series and that ran extremly nice too. Stock engine with 2,0E cam, a set of 45´s and 2,5" Gr A Exhaust gave me 148bhp on the dyno, that is a 33hp gain on a stock engine! I have also had a Monza from 78 with tripple 40´s Quote Link to comment Share on other sites More sharing options...
SENNA1 Posted July 13, 2011 Author Share Posted July 13, 2011 (edited) Thank you both guys! The other mod i have on this car is the 'fast road Kent cam' .Don't know if this makes a diff on the whole story. So,as i understand i just have to stay with the 45's as they are then. P.S. Is there a diff between 'spanish' & 'italian' webers? Edited July 13, 2011 by SENNA1 Quote Link to comment Share on other sites More sharing options...
lamchop77 Posted July 13, 2011 Share Posted July 13, 2011 Thank you both guys! The other mod i have on this car is the 'fast road Kent cam' .Don't know if this makes a diff on the whole story. So,as i understand i just have to stay with the 45's as they are then. P.S. Is there a diff between 'spanish' & 'italian' webers? Check the actual code of the cam as there are 7 cams listed by kent for your engine. Some of these are only suitable for injection so would be good to know exactly waht you have. Its usually stamped on the end of the cam. Don't think that there is any physical difference but i think that there were quality issues with the spanish made ones at one point. HTH Chris Quote Link to comment Share on other sites More sharing options...
SENNA1 Posted July 13, 2011 Author Share Posted July 13, 2011 Don't know the code for the cam. The only think that i know is that it's 'fast road' Cheers Quote Link to comment Share on other sites More sharing options...
monzta Posted July 13, 2011 Share Posted July 13, 2011 There is no difference performance wise regardig wether they are made in Italy or Spain. Best quality is the italian ones though. But we are talking minor differences here, nothing worth noticing. Webers are in general not the best choice, Dellorto or Solex are much better and don´t need adjustments as often as the Webers. You should get them re adjusted aprox 3-6 months after the initial adjustment and every 6-9 months after that. Dellorto´s and Solex need adjusting once a year aprox. Even though your cam might be best suited to injection doesn´t mean that you can´t use them with carbs. But i would check it anyways as this might have something to do with the adjustment settings. When the engine is ready you should get it adjusted on the dyno, it is not something you can do yourself as it require some speciel measuring tools. When running a tuner cam you should definatly not go down in size on your carbs ! Quote Link to comment Share on other sites More sharing options...
SENNA1 Posted July 14, 2011 Author Share Posted July 14, 2011 The bigest problem with the car is that,once the engine gets warm,the revs rises at around 1500rpm Quote Link to comment Share on other sites More sharing options...
monzta Posted July 14, 2011 Share Posted July 14, 2011 The bigest problem with the car is that,once the engine gets warm,the revs rises at around 1500rpm You need to adjust it when its warm, if it then has problems running when cold you should use the choker and install a cable for this. Another possibility could also be that your ignition vaacum retard is screwed? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.