Thanks for the kind comments and welcoming remarks!
I think the jetting trouble I'm having with the Delorto DHLA45
(on a BMC "A" 1275) could be solved by equivalent measures to
those taken on a Weber DCOE. In particular, the engine goes
very flat (VERY flat) at 5500 rpm pulling in 4th. The cam
should be in full swing here -- it's around 280 degree duration
-- and it pulls well in lower gears with lots of mid-range.
The other local Elevens, with similar engines and gearing, pull
'til the drivers run out of guts (like 8300!).
My plugs look a little lean, but not too bad. Current jetting
(with Weber equivalents):
Choke Venturi Main Emulsion Air Corr. Idle Bleed
36 4.5(.1) 150 7772.6(F16) 180 55 F9(.7)
I had been running 160 mains (richer), F11 emulsion (much leaner)
, and 220 air corrector (leaner) 'cause that's what came with
the carb, and they pulled better on top but fouled the plugs
very badly and popped back on decelleration. The current guess
is based on Hammill's recommendations in "Tuning Weber and
Delorto Carburators".
So, what part of the jetting is in force around 5500 revs???
Last track day I got stuck behind a Toyota "Shooting Break"
and stayed there 'til I blew the head gasket. I need top end!
- Mark Joerger
Salem, Oregon
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