We had 8 WyCROCers show up for a dyno day in Colorado Saturday,
thought y'all might be interested in the results..
All U20's, all have EI distributor's (I think all but one were
Gary Boone distributor's). I tried Keith Williams SU Brit needles
for comparison. The MC's came out better than N17's by 5 hp, and
waayyyyyy smoother air/fuel mix thru the rpm's (3200-6500). I
didn't list the guy's names below that aren't on the roadster list:
hp torque
1 81.7 97.5 SU's, B-cam
2 90.9 103.9 Solexes, aftermarket 'hot' cam of unknown origin
3 91.8 100.6 45mm Webers, ported, L20B cam grind
4 Dan Neff 95.0 104.8 SU's, N17 needles, B-cam
5 97.3 103.3 Solexes, B-cam
4 Dan Neff 100.1 107.8 SU's, MC needles, B-cam
6 106.2 111.1 Solexes, A-cam
7 John Over 108.4 115.1 Solexes, B-cam
8 Gary Boone 117.1 117.7 TWM carbs, B-cam
Conclusion: Um.. carbs and cams ain't all there is to it? Sheesh,
you got me!!
I'm still trying to figure out how I could end up with 18 more hp than
the other SU/B-cam guy with a fresher engine! (he also only gained 1 hp
with the MC needles)
Clearly being a member of the roadster list gets you more hp :) ..
#6 (Solex/A-cam) gained *14* hp by removing his Supertrapp plates (he
only had 4 on there)
While these nbrs are adjusted for sea-level (figure 23% less O2 up
here in the Rockies), I still wonder if the tweaks needed to lean the
fuel don't limit the potential vs a comparible sea level tune (at
sea level)...
John Over's just-completed overhaul looks like a topnotch job, yet
he only got 2 more hp than #6 A-cam/solex on an older motor! The
implication that a B-cam only gets you 2 more hp seems kinda
dubious...
So, what kind of nbrs do you flatlanders get? Do (shouldn't?) these
compare? If they do, then mine's losing 35 hp between the crank and
the wheel?? Or is the 135 hp rating in 1969 a different scale or
something? What's the 100% stock U20/SU/A-cam hp supposed to be at the
wheel?
The 5 hp gained on mine IS noticeable on the road (you betcha I left
those needles in!) in acceleration, hill climbing, and to a smaller
degree (I'm not sure anyone else would notice), smoother acceleration.
Any thoughts to educate me would be appreciated, altho I'm not laying
awake nights worrying about it, 'cause I'm here to ENJOY THE RIDE.
thanks,
dan neff '69 2000
colorado springs, co
http://www.wycroc.org
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