which is better Weber or Dellorto

[PeterCoupe]

Hi all

I will be upgrading fuel system, I need some advice if anyone have regarding big carbs.
Which is better, easier to maintain and tune; 40 idf or 48 dellorto DHLA.

I have 42 dcnf's right now, I heard dhla sometime ago and they sound little bit differently from Weber, or i need to see specialist...

any comments

[Wallace]

48's are way to big. 40 side drafts would be the best option for a street car. 45 will not be as smooth at low revs (say below 3000 rpm). Sidedrafts are better than down drafts (and the manifold's cheeper !). Weber jets come in a larger range of sizes then Delorto's and are more readily available.This is pretty much what Guy Croft reckons !

[cthargiss]

For a full race engine, 48's are about the maximum usable size. With 48's, throttle response and mixture control below 4000 RPM suffer badly, However they do offer more power above 9000 RPM. For street applications, 42's offer the best compromise of power and drivability. 40IDF's on a modified FIAT 125 intake make for a clean installation on a 1.8L. Not enough hood clearance on a 2.0L.

[PeterCoupe]

Yeah I know that I will be in for quite a bit of trouble with 48's. It took me while to get 42's sorted, air velocity mainly through carbs.

I do want to upgrade from 42, I will significantly upgrade complete package from this setup.

That comment about drivability under 4000rpm gives me worries, I can live with bad drivability around 2500rmp, but 4000rpm is to much.

I was planning on fully balanced engine with red line at 9000rpm and 190hp or strong 170hp with increased durability on main components.

Peter

[Hamish]

Peter,
I've always found that Dellorto sidedraughts stay in tune for much longer than Webers - it could be because there is (apparently :?: ) more adjustment available in a Dellorto.
Wallace is right, unless you're going full race then 48's are just way too big. 40's give a nice balance and I'm told - although I'm not sure myself - that sidedraughts ultimately give better results than downdraughts (comments anyone :?: ) so 40's or 'lumpy' 45's would be the alternate - mind you, throttle bodies and mapped ignition would surely be the way forward for real big gains :wink:

[PeterCoupe]

Hi Hamis

I was looking at that option of FI, but it would cost arm and leg to get it in, unless I scavenge some wrecked car somewhere.

FI will be to complicated for me, I am points and carbs kind of person (I will run crank trigger for 48's, must). Also, adding more and more circuits would drive me mad and equally important......I love deep sound of twins.

I have 42's now, but I wonder what will 48'd do to it :D
42's are not lumpy in my application at all, so I was thinking that going to 48's I would get some lump around 2500rpm with which I can live.

Peter

[cthargiss]

Peter, Unless you are building a 200+ BHP, 10,000 + RPM track only full race engine, stay away from the 48's. I was not kidding when I said that you will get serious throttle lag, jerking, and load up below 4000 RPM. For a serious street engine in the 160-180 BHP range 44IDF's or 45 DCOE's are the best way to go. The 48's and 50's should only be used on engines with 12.5:1 CR or better, cammed for the 6000 to 12,000 RPM range running 120 octane race fuel. The Climax 2.5L F-1 engine used 48mm carbs, and it was about the last thing you want to try to drive on the street.
Craig

[arc]

As far as dellorto vs weber, apparently dellortos give better fuel atomisation although the power surge can be not as smooth. I'm really not sure of the truth behind this but I guess a too smooth surge can account for lack of character. Not to mention that dellortos are far cheaper to buy second hand and I do keep hearing that they may very well be better.
As far as part availability, I wouldn't believe everything that's said. It seems that everbody's brain washed into thinking not only that webers are the undisputed best but also that you can't get parts for dellortos. I'm no expert but I've found plenty of places for parts.
Anyway sounds like 45's are the go.
Jeremy.

[Shant Fabricatorian]

If you are still intent on 48s having a supertanker in permanent close attendance might also be a good idea. :oops: :wink: