Fuel economy

Phoenix · Post by **Phoenix** » Tue May 10, 2005 11:55 pm

sorry...........

bstardchild · Post by **bstardchild** » Tue May 10, 2005 11:58 pm

Yeah sold it with 185,000 miles - the first owner never bothered to record the mileage so just had the info from 30,000 onwards

Phoenix · Post by **Phoenix** » Wed May 11, 2005 12:00 am

lol i might start doing that once i've rebuilt it see what its like then. should be better with a new gasket on. Its soon going to drop though when the 40's go on

bstardchild · Post by **bstardchild** » Wed May 11, 2005 12:01 am

Phoenix wrote:lol i might start doing that once i've rebuilt it see what its like then. should be better with a new gasket on. Its soon going to drop though when the 40's go on

With 28mm chokes

Phoenix · Post by **Phoenix** » Wed May 11, 2005 12:04 am

lol i'm still learning about Twin 40's setup.

the ones i have are for a 2L pinto so they need stripping, rejetting and servicing, so it'll be a new world to me.

Got quite a lot of info about them though so i should learn a lot

bstardchild · Post by **bstardchild** » Wed May 11, 2005 12:13 am

Phoenix wrote:lol i'm still learning about Twin 40's setup.

the ones i have are for a 2L pinto so they need stripping, rejetting and servicing, so it'll be a new world to me.

Got quite a lot of info about them though so i should learn a lot

So in your reading material what it might say is that air speed thro the carbs is fairly important - big chokes = slow air speed poor fuel atomisation and crap mpg as well as poor performance

Smaller chokes = faster air speed - better atomisation and more consistant fuel pick up and that means more poke

2L pinto carbs are fine provided you change the chokes and jet accordingly

Phoenix · Post by **Phoenix** » Wed May 11, 2005 12:17 am

lol i'm glad there people out there that know what the hell their on about

i get the bit about fuel atomization (sp?) as i used to fit Nitrous and thats very important, and i get the bit about airspeed, but the bit i don't get is how the dam things really work

got an article in pratical performance car magazine but i'm reading it really really really slow to try to get my head round it all

bstardchild · Post by **bstardchild** » Wed May 11, 2005 12:25 am

Phoenix wrote:lol i'm glad there people out there that know what the hell their on about

Phoenix wrote:i get the bit about fuel atomization (sp?) as i used to fit Nitrous and thats very important, and i get the bit about airspeed, but the bit i don't get is how the dam things really work

Plenty on the web if you search carefully - me I wouldn't bother with Webber twin 40's (too old skool and very very primitive) - I'd be different and stick a set of bike carbs on it - Gixer 750 (early flatslides or even CV jobbies would be OK) would be very nice and also very easy to set up as they only have 2 jets (idle and main) and needle height is adjustable so you can jet it for tickover on the idle jet midrange on the needle and then change the main jet for top end WOT

Phoenix wrote:got an article in pratical performance car magazine but i'm reading it really really really slow to try to get my head round it all

Sounds like at least you are trying to walk before you start running

Phoenix · Post by **Phoenix** » Wed May 11, 2005 12:31 am

yeah i might go for the bike idea now you mention it. Might just look into it.

and before i do anything to my car i always read into it as it gets so much abuse i'm running a fine line between making it stupidly quick and blowing it up

the 40's need stripping anyway too so i need to know how to do that before i can do anything anyway

optima21 · Post by **optima21** » Wed May 11, 2005 9:53 am

if you're fitting twin 40's and setting them up yourself, a good book is "How to build and power tune Weber & Dellorto DCOE & DHLA carburettors" by Des Hammill.

it shows you how to strip and rebuild the carbs and how to selct jet sizes etc.....

... but be weary as getting several different jets/chokes/emulsion tubes/auxiluary venutri's can get seriously expensive for experimentation.

Phoenix · Post by **Phoenix** » Thu May 19, 2005 9:52 pm

lol so this is where the whole point of fuel economy goes through the window

Tahrey1043 · Post by **Tahrey1043** » Thu May 19, 2005 11:46 pm

so that's why the 1.0 has smaller intake diameters then? interesting.....

(of course a large choke is good if you have a monster engine, as there'll be tons of air caning through it anyway)