Esprit2 wrote:There is no one universally correct setting for a 1700cc Twink.
Smaller, 32-33mm chokes may improve low-speed driveability and make the engine easier to drive in commuter traffic. But the choice of QED 420 cams indicates you might have loftier plans for which small chokes aren't the best choice. The cams & small chokes won't be pulling on the rope in the same direction.
Tim Engel
mbell wrote:Any recommendation from on here are going to be hit and miss due to all the variables. The settings provide with the cams are likely to be as closer than as anything suggested here.
As noted above, there are a lot of variables, so anything posted here should be considered as perhaps a starting point. But, you already have a starting point from QED.
Hopefully, to not add to the confusion, but to provide another data point, here are the settings for my 1700 Twincam. What is notable, and contrary to the common wisdom, is that the high power/torque derived are with 40DCOE's and 32mm chokes. But, a lot of variables at play. (And no, again, this was not from a "juiced" dynamometer).
1700 cc. Long stroke, stock block
Builder: Dave Vegher
181 Bhp @ 6900
143 lb-ft @ 5100 (~flat from 4000-7000 - dyno range), car pulls strongly from lower rpms
7000 redline, street engine
Very tractable, no hesitations from idle to 7K
Idle, dead smooth; @ <1000
32 mm chokes, 40 DCOENew SAS head
Valves: 1.625 / 1.375
0.44" lift Kent cam, short duration
Compression: 10.3
Pump fuel
F16, 40 pump, 140 main
Intially: air 165, idle 45F9
Later, changed air to 180 and idle to 50F6