British SU float chamber lids - help needed with different types of lid

[1600dave]

Firstly, apologies as this isn't strictly a Z-related question, but I figured I'm more likely to find someone here with experience running British SU's on L-series engines.

 

I recently upgraded from the original 38mm Hitachi SU clones to to a pair of British 1 3/4" SU's on my L18-engined racecar, and am now experiencing carb problems on hard cornering (but only left handers). Seems to me as though its starving for fuel - it cuts out in the corner, and plays up till about 20 - 40m out of the corner, at which point it picks up again and is happy till the next left hander.

 

Googling suggests it may be an issue with the orientation of the hinge for the float, which apparently should ideally be positioned facing forward and at right angles to the axis of the car. Which brings me to my question - has anyone ever played around with this stuff ? Is this likely to be a reasonable lead to follow up ? And is anyone able to provide the part number (should be cast into the float chamber lid) for a lid that orients the hinge correctly ?

 

I built my carbs up out of odds and ends, with two different lids both having hinges in different orientations.

[Thomo260]

I ran 1 & 3/4 SU's of a Triumph on my old 260Z and had no issues at all, including a track day at Simmons Plains. I never did anything different just tuned them.

I can find a pic to post if you like?

 

Thomo

[1600dave]

Thanks for the reply - mine are also off a TR7. I've since found a float chamber lid that places the float in the correct plane (well, the plane recommended on a few MG sites). The correct lids are off an MGB - the 1 1/2" and 1 3/4" share the same float chamber apparently. I'll do some experimentation before the next race meeting.

 

If that fails, I found that Datsun / Hitachi float chambers mount up to the British SU's perfectly, only need to use the Datsun mounting bolt and modify the jet hose to attach to the Datsun float chamber.

 

Of course, there is the possibility that its nothing to do with float heights