Dave wrote on 02/19/16 at 05:12:12:Art Webb wrote on 02/18/16 at 18:16:19:Dave wrote on 02/18/16 at 10:55:00:The thing you should pay attention to......is that the DYNO sheet shows that the Savage engine is making a lot of torque by 2,500 rpm.....and the torque is strong from 3,000 up to 5,000 rpm.
Multiple cylinder engines don't make toque at those low revs. (unless it's a diesel).
not true
My XS 1100 could be accelerated smoothly and strongly out of a tirn at any RPM over 2k
it was one of the most tractable engines I ever experienced
There is no doubt that big engines can make torque.....but I have no doubt the XS1100 made a lot more torque at 6,000 rpm than it did at 2,000 rpm. The point that I was trying to make is that our big single has nearly all of the torque available by 2,500 rpm.....and that doesn't happen on engines with multiple cylinders (same displacement). A 650cc single is going to make more low end torque than a 650cc twin. There is no doubt that a Harley V-Twin makes a lot of torque.....they do that by bolting two big singles together to make a V-Twin!
There is a new breed of bike out today.....they are made to have a big flat torque curve that doesn't require a lot of bear changes when riding. Most of them are big twins like the Yamaha MT01, Suzuki M109, Moto Guzzi Audace, BMW 1200R.
http://www.lazymotorbike.eu/technical/torque/ with no access to a dyno, I can't tell you ezact # at 2k
Peak torque was 65 lb ft at 6500 RPM
Savage engine's peak torque is at 3 or 4k IIRC
Savage redlines at 6500 or 68, I forget which, XS redlined at 8500
top gear was similar for both bikes, with the S40 spinning 4k or so at 70 I do believe, and the XS spinning 4k at 70 as well
the XS would pull smoothly out of a turn at 25 MPH in 5th gear, and that's with the parasitic losses of a shaft drive
tMy S40 would not
This is based on riding the two bikes back to back on the same roads, often on the asmae days
you didn't say multis don't make most of their torque at 2k, you said they don't make torque at 2k
for most multis that's true, the XS, and a few other multis over the years, though, have shown that they can
even the moto mags were shocked at how much grunt it had down low
there was a definite bump at 65K, if you were brave enough to keep the throttle open, but it was power everywhere
yes, the S40 will pull a multi of similar CCs, off the line,, because it's 1 pisotn is 2x the size, or even 4x the size, of the one in the multi, and it is a long stroke motor, built for torque, but if it's designed to, a multi can make torque at 2K
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