Do you like torque

swooshdave said:
comnoz said:
Thanks for the link. I had not seen that one before. Jim

See the edit above.

Just like a picture, wrap the YouTube URL with the <video> tags to embed it. Jerry even provided a button.

And, um, what was that guy trying to do?

I guess he had just cleaned the carb and took it for a rip up the street. Looking at the puddle of fuel it was probably a good thing he didn't have a cigarette.

I know how to embed the video. I just figured that took up more expensive space on the forum- but I don't know.
 
My P!! was like that taking off, being so light on a street tire, plus I get to do exactly that too often on THE Gravel. Ugh, He was still going off a prior sense of dry traction vs throttle but hit a wet spot w/o knowing it, ZIP! No lag on snapping that throttle off idle.

My crude figures imply its 9.0 sec 1/4 m 151 mph capable. Corrections invited.
Thanks for sharing more of your extremist efforts. Don't get a ticket or a mention in the new paper.
 
Man machines like JIm's here turns me on like seeing iconic Mrs Emma Peel in the flesh back when she was fresh as this light power house.

He lost it soon as rear dipped in gutter water, so lucked out not to hi sided bike on head or whip lashed skull to spatter so fast wouldn't even know it dead.
[video]http://www.youtube.com/watch?v=cJDdo7xMCcc[/video]

This is how it gets too easy on THE Gravel if hitting unseen extra loose spots or pot holes then suddenly splashing into the Grit. Yet when nothing bad happens its a gas to get cockeyed crossed up on spun rear you butt steer and just hang on for the thrill. Its how my drag bike made the best tramac grip feel and so will Jim's Vtwin Torque Monster, with extra impulses to snap throttle more and more > no matter what one's logical side commands, it ain't near fast enough logic compared to biological reflexes like sex climax. BANG ya Off>>>>

These examples are in similar power/weight zone but long swing arm cheaters.
[video]http://www.youtube.com/watch?v=ZLnMr83DJJs[/video]
 
So Jim, some details on the engine? Is it a two valve or four valve head. Assuming it's a balde and for crankshaft (ala. S&S). I picture of the dyno pull torque/power/rpm results should get the juices flowing.
 
Dances with Shrapnel said:
So Jim, some details on the engine? Is it a two valve or four valve head. Assuming it's a balde and for crankshaft (ala. S&S). I picture of the dyno pull torque/power/rpm results should get the juices flowing.

The crankshaft is an S&S. It is a two valve billet head. It runs 7.5 to 1 compression.
I will have to save a dyno strip when it comes back for the final tune after the exhaust replacement.
I am kind of afraid to really hammer it on the dyno. I had a primary chain problem once a few years back. Jim
 
comnoz said:
I am kind of afraid to really hammer it on the dyno. I had a primary chain problem once a few years back. Jim

Thanks Jim. How's the valve train set up. I seem to recall reference to twin cam. Is it cam over bucket, cam over rocker?

Why does your statement above bring to mind a picture of you on the roof of your garage/shop with a few replacement shingles and a bucket of tar patch?
 
Dances with Shrapnel said:
comnoz said:
I am kind of afraid to really hammer it on the dyno. I had a primary chain problem once a few years back. Jim

Thanks Jim. How's the valve train set up. I seem to recall reference to twin cam. Is it cam over bucket, cam over rocker?

Why does your statement above bring to mind a picture of you on the roof of your garage/shop with a few replacement shingles and a bucket of tar patch?

It is a pushrod motor with hydraulic roller lifters. This motor is actually a single cam now that I think about it.
The newer motor is a twin cam but still a pushrod motor.

I was just lucky to not be straddling the bike when the chain got loose. Jim
 
What a way to loose it in the saddle!
I'm encouraged to see an example of extra hot air cooled twin getting away with it.
Btw please drop the other shoe, how much boost is being applied and what octane?
Any special spark plugs needed? Do you ever need to shift out of top?
 
hobot said:
What a way to loose it in the saddle!
I'm encouraged to see an example of extra hot air cooled twin getting away with it.
Btw please drop the other shoe, how much boost is being applied and what octane?
Any special spark plugs needed? Do you ever need to shift out of top?

The manifold pressure is 170 KPA at the rev limiter setting of 5700. The motor could turn faster but the blower can't. We just use premium pump gas and 9 range plugs.
You definitely need to use the tranny. With a belt driven centrifugal supercharger like that it looses it's efficiency really quick when the revs drop. So the powerband is quite narrow. It would be a lot more fun with a positive displacement blower or staged turbos. Jim
 
comnoz said:
The manifold pressure is 170 KPA at the rev limiter setting of 5700.

So is that 170kpa absolute or is that above atmosphere. If that is absolute then the max boost would be about 10 psig whereas if it is above atmosphere it would be around 34 psig. I know the Drouin superchargers were good for about 10 psig.

34 psig seems a bit excessive but then the bike seems a bit excessive.
 
The 170 KPA or 1.7 atmospheres is definitely absolute. Standard pressure at this altitude is around 83 KPA. Jim
 
comnoz said:
The 170 KPA or 1.7 atmospheres is definitely absolute. Standard pressure at this altitude is around 83 KPA. Jim

So you are working with about 82% of what's available at sea level. Sea level is about 101.38 kpa (14.7 psia); so you are at around 12.04 psia.
 
Dances with Shrapnel said:
comnoz said:
The 170 KPA or 1.7 atmospheres is definitely absolute. Standard pressure at this altitude is around 83 KPA. Jim

So you are working with about 82% of what's available at sea level. Sea level is about 101.38 kpa (14.7 psia); so you are at around 12.04 psia.

Yeah, that would be about right. I have never used a boost gauge on it.
 
170 kPa = 24.6 PSI converters say. RBRacing boost/CR calc with 7:5 static CR implies over 19.5:1 CR at 1000 ft altitude. That it lives on pump gas and tolerates heat loads is very encouraging to read. John, Dances here tells me the Drouin bothers handling so I'm so pensive to handle it my real Plan A is 38mm QuikSilver carb but where's the glamor in that eh.

I'm sorry to hear its narrow power band as implies dangerous to keep on the boil under controlled traction, ugh, best wishes pilot knows what he's doing with it. Yet in light bike troque Monster like this, narrow power band don't mean same as normal, as pilot should have instant tire spin on tap anytime to top end. I'd think a big block for off boost initial grunt then exponential, 'soft', centrifugal boost increase would be best combo for real life and road race work. Positive compressor are more fun in cars that couldn't over come tires at low rpm w/o it but they also don't fall down when rears spin out in balanced turns, they can either drift compensate or back off for another aim w/o being super man skilled or lucky. John and others say impeller gyro effect becomes a handling issue, ugh. Land speed and pure drags don't need the low rpm side of real life. Hope they pay well for your special attention.
 
Oh Ok I was trying not to confuse you by too many decimal places to keep track of and figured if I did I'd be accused of exaggerating again, sheeze! I'm familiar enough now with online calculators to realize its more realistic to round off on the conservative side. Using known dyno reports on particular engines allows some juggling of calculator inputs to match up and guide one on extrapolating how to take the onscreen results. Ideally fates permitting I'd like to ride next Ms Peel to Texas to party with them, then follow Jim Comstock back to CO and churn her up on his dyno, then put on new tire to come home on. If a sports bike 'puterized over powered balloon tire wants to play along the way I'll try hurt their feeling as fast as possible then get back to cruise state trace. Racers do neck and neck contests, but that is too stupid in public so I either hang back bored or flat disappear on Peel. May not be able to keep up with this 2.1 liter brute on freeways and drag strips but it wouldn't stand a chance if any leaning on hi power involved. Eat you heart out if that's not your experience on your Commando like motorcycles.
 
Back
Top