theres a valve in me butterfly , dear Liza.

Posted By : Calvin Andrew, 25-Sep-2006, 11:13am

HI all,

say you gas flow and port your head, then your inlet manifolds are matched to the head, then you put the richer needles and springs in the carbs and then you put trumpets on and then you have hi flow pipercross filters all in the hunt for a good flow to the carbs.

then when tuning them you see that there is an overrun valve on the butterfly. when it is open, this centimetre and a half chunk of spring and valve is right in the middle of the air/petrol flow.

is this causing an obstuction and if so can i replace the buitterflies with solid ones?

cheers Calvin

Followups :

theres a valve in me butterfly , dear Liza.

Posted By : Jason Chinn, 25-Sep-2006, 11:28am

Take 'em out - solder, JB weld or epoxy the holes

theres a valve in me butterfly , dear Liza.

Posted By : George Ralph, 25-Sep-2006, 01:30pm

Yes get rid! Some advocate soldering them up, but replacement with plain new ones from Burlen is not that expensive and probably the best option.

theres a valve in me butterfly , dear Liza.

Posted By : Dan Owen, 25-Sep-2006, 03:11pm

If they're sound, solder them up and save some cash.
theres a valve in me butterfly , dear Liza.

Posted By : Chris Taylor, 25-Sep-2006, 09:57pm

And while you are at it, you can reprofile the spindle almost flat to flow better. It only needs to be round where it fits in the bearings in the carb body at each end.

Section : General

theres a valve in me butterfly , dear Liza.

Followups :

theres a valve in me butterfly , dear Liza.

theres a valve in me butterfly , dear Liza.

theres a valve in me butterfly , dear Liza.

theres a valve in me butterfly , dear Liza.