Float setup on Twin 40's

[LewisJC]

I've got a 1.3 sport, running a 300 cam and considerable head work, and I'm upping the jetting of my carbs to competition spec. Does anyone know how I should set the float height to match?

Cheers for any help

[S_Gault]

strip them, remove needle valve and chack it for a wear line.. replace it with a 175, replace float pins and chack floats arent punctured.

Dont change the std float settings, its not an issue, i only tweak themwhen on slicks.

Steven

[LewisJC]

Ah, cheers.
I've got a pair of carb rebuild kits, and took the jets sizes off the Performance Nova page on the sport. should be good...

[S_Gault]

post them and I'll give you my thoughts..

I worked for weber for 5 years.

Steven

[LewisJC]

Idle jet 125, Main jet 52 f 26 (although only 50f26 available apparently), Air 170, Pump 40 (unchanged) Emulsion tube F16, Choke 28 mm/28 mm (unchanged). And you say go with 175 needle valves too.

Sound good or pants?

[S_Gault]

I tend to use F11 emulsion tubes on modified engines, I'll check my old notebook again tonight..

125mains seems rich especially on 28mm chokes. Change them to 30mm.

Idle is big time rich- 55f6? Id have something like 45F9 in it. air seems fine as does pump jet.

How high a sepc is engine? as Id have a few other ideas about this one.

Steven

[LewisJC]

I'm running a rally spec cam, 300 duration and suitably high lift, and uprated springs, with a flowed 1.3SR head, wasted/reprofiled valves. then into an ashley 4 branch manifold. Twin K&N's, facet fuel pump, malpassi filter king.
I'm also planning on fitting a vernier pulley to get the best from my cam.

I lifted this jetting from the pccuk.net page on the sport, apparently its the setup that was used on competition cars. check out www.pccuk.net/page377.html

Cheers,
Lewis
P.S Its good to find someone who actually knows what they're on about when it comes to carb setup!

[LewisJC]

should say, I haven't actually ordered the jets yet, so if different is better, then fine!

[S_Gault]

are you on solid followers or hydralic, and what sort of revs do you use?

Steven

[benji]

sorry to hijack but.... how much differance would a 300 deg cam on solid lifters make over a 290 on hydralics? and how worse would it be at low revs?

cheers

ben

[LewisJC]

I'm still using hydraulics. I've though about solids as occasionally one lifter gets a touch rattly if its been at high revs for a while, but I don't know how much they cost or where to get them.

But for now, hydraulic lifters and about 8000 rpm tops, generally upshift at 6750 - 7000rpm though. Not had valve bounce, just not sure how hard to push it!