Webers or Dellortos
Discussion
Im looking at putting twin 40s on a midget, but im not overly familiar with webers or dellortos personally so was wondering what the pros / cons of
each were.
Theyre not going onto a stock engine, its lightened and balanced etc, so the twin 40's seemeed like a reasonable choice all things considered.
thanks
Neil
each were.
Theyre not going onto a stock engine, its lightened and balanced etc, so the twin 40's seemeed like a reasonable choice all things considered.
thanks
Neil
Do you mean twin 40's as in a "split pair" or a single twin-choke 40 ?? No really relevant to your question....... but makes a big difference to the installation !!
As far as I'm aware there is little to choose between them, depends on which your local tuner/dyno operator is more familiar with I guess. Most people seem to want webers for no readily apparent reason. Carb fed Lotus' (Loti ??) use dellortos, so perhaps there's an avenue in finding someone who knows a bit dellos there.
Not much help really !!
Phil.
As far as I'm aware there is little to choose between them, depends on which your local tuner/dyno operator is more familiar with I guess. Most people seem to want webers for no readily apparent reason. Carb fed Lotus' (Loti ??) use dellortos, so perhaps there's an avenue in finding someone who knows a bit dellos there.
Not much help really !!
Phil.
There is no point in putting twin 40's or Twin 45's onto a 5 port 'A' or 'B' series engine as you would have 4 choke tubes feeding 2 inlet ports, i.e. there is no advantage.
You can fit a single, twin choke 40- or 45DCOE, or the Dellorto equivalent, to good effect, so long as your head can benefit from the improved flow over twin SU's and you have the right cam (Kent 286 or 296).
A Weber, or a Dellorto, won't give much of an advantage over, say, twin 1.5" SU's, but you get better throttle response due to the fixed jet design of the Weber/Dellorto. You do need a good cam to work with a Weber, big valves, and a well gas-flowed head. Otherwise, my advice is to stick with the twin 1.5" SU's.
One other thing, the jetting of a Weber/Dellorto is more difficult than an SU set-up as the jets must be absolutely correct. It can only be done properly on a rolling road. If that's not done it's easy to run too rich and get bore-wash at low revs, which causes rapid bore wear and thus oil burn/smoking.
Personally I'm not a Weber or Dellorto fan on a 'A' series. However, others have got some excellent results with the side-draft Webers and my buddy with the 1330 cc Clubman GT rally car gets about 115 bhp on a 45DCOE Weber with a 286 cam, a really good head and a tubular steel inlet manifold/big lcb exhaust.
I guess you pay your money and take your choice.
I hope this helps,
Peter
You can fit a single, twin choke 40- or 45DCOE, or the Dellorto equivalent, to good effect, so long as your head can benefit from the improved flow over twin SU's and you have the right cam (Kent 286 or 296).
A Weber, or a Dellorto, won't give much of an advantage over, say, twin 1.5" SU's, but you get better throttle response due to the fixed jet design of the Weber/Dellorto. You do need a good cam to work with a Weber, big valves, and a well gas-flowed head. Otherwise, my advice is to stick with the twin 1.5" SU's.
One other thing, the jetting of a Weber/Dellorto is more difficult than an SU set-up as the jets must be absolutely correct. It can only be done properly on a rolling road. If that's not done it's easy to run too rich and get bore-wash at low revs, which causes rapid bore wear and thus oil burn/smoking.
Personally I'm not a Weber or Dellorto fan on a 'A' series. However, others have got some excellent results with the side-draft Webers and my buddy with the 1330 cc Clubman GT rally car gets about 115 bhp on a 45DCOE Weber with a 286 cam, a really good head and a tubular steel inlet manifold/big lcb exhaust.
I guess you pay your money and take your choice.
I hope this helps,
Peter
Thanks for the replies guys, It was a bit stupid of me not to mention that my midget is a 1500 which has an 8 port head, so it can take advantage of the twin setup. I tend to lurk abit on the Mini forum and know theres some excellent knowledge on here which is why i posted on it despite it not being an a-series!
Cooperman - from what I know already I think what you had to say about the 1.5 SU's still hold true for the triumph engine in the 1500 even though they are the OE carbs. I guess I'll find out whether theyre shoveling enough fuel in when I get it dyno'ed!
Cooperman - from what I know already I think what you had to say about the 1.5 SU's still hold true for the triumph engine in the 1500 even though they are the OE carbs. I guess I'll find out whether theyre shoveling enough fuel in when I get it dyno'ed!
There is another benefit of sidedraught carbs v SU's and that's the pump jet...couple of light dabs and it'll start much easier I've found...in the summer no need for choke @ all !
P.S. I have a pair of Del 40's for sale in an old ad here on PH...but u won't get me to part with my 45's.
P.S. I have a pair of Del 40's for sale in an old ad here on PH...but u won't get me to part with my 45's.
There used to be a book available called 'Power Tuning SU Carbs'. It detailed how to gas-flow the carbs and it improved the flow of a 1.5" to almost that of a standard 1.75".
I once had a 1330 Cooper 'S' with twin HS6's (i.e. 1.75's) and they were very good with a 544 cam and a Longman head running at 10.6 to 1 c.r.
In fact, a pair of 1.75's might be good on a 1500 Midget. I got mine off a friend who had a Dolomite Sprint, on which they are standard, I believe, when he went to HS8's.
I once had a 1330 Cooper 'S' with twin HS6's (i.e. 1.75's) and they were very good with a 544 cam and a Longman head running at 10.6 to 1 c.r.
In fact, a pair of 1.75's might be good on a 1500 Midget. I got mine off a friend who had a Dolomite Sprint, on which they are standard, I believe, when he went to HS8's.
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