thanks lsrcb175!lsrcb175 said:Looked up the BUB rules and it looks like they just want tires adequate for the speeds you run and leave it up to the owner to make the correct choice. Therefore, no specific requirements like ECTA and SCTA .
Good to go!
that was fun!Cafe Mike said:http://youtu.be/jFAB5qVDT-8
Not sure if you found this. Your cb200 is pictured and sound clip @ 6:15. Small world
we got our welding gearsimo said:Happy anniversary,
How were your holidays? What's new with lucky?
Holidays were great! Zeke and I have been busy converting his playground into a place to house our welding gear. Lucky got some new Sava's for the Salt rated at 105 mph and Sonreir just sent us our side decals. Cafe Matty sent us some goodies from Cone Engineering…simo said:Happy anniversary,
How were your holidays? What's new with lucky?
Thanks Sonreir! So the triangle gets taller and the angles change both at tdc and bdc...trying to think of an amusement park ride that would mimic dwell...Sonreir said:It's all in the trigonometry. Think of the rod and the crank arm as two sides of a triangle. The third side is the distance between the piston and the crank centerline. As the crank is rotating, the piston moves up and down, but it doesn't move in exact relation to the crank because of the changing angles between the crank and rod and rod and piston. As the piston nears top dead center, the speed at which it is moving decreases. The rate of that decrease has to do with rod length.
With a long rod, that rate is slower, so the piston spends more time in and around top dead center than it would with a short rod with the same stroke. What makes this really interesting is that the opposite holds true when it comes time to measure piston speeds on the lower half. So longer rod slows the piston at TDC, but speeds it up at BDC.
This change in piston speed has an important effect on the breathing of your engine. Short rods tend to favor long durations with lower lift while long rods like shorter durations with higher lift (in general). The timing on the cam becomes important as well. If the piston is moving faster in the bottom hemicircle of rotation, then you want the intake events happening later and the exhaust events happening sooner.
I don't have a ton of time at the moment, but I'll get a drawing and some math going a bit later.
Texasstar said:Reading Smokey Yunicks Power Secrets. He says by pushing the rings to the top of the piston it allows the pin higher in the piston reducing the overall length of the piston and allowing for a longer connecting rod and that a longer connecting rod is paramount increasing the rod ratio. What I can't wrap my head around is that it doesn't increase the overall length of the piston and connecting rod.
secret is safe and a whole lot easier than changing the bottom end same mental note as before... need more squish and a bathtub just read what Mr. Bell said. If we can eliminate the high dome piston it solves several inefficiencies...and that dang cb200 piston is significantly heavier than the 175! Why did they make it so heavy? Lower compression, lower performance, cheaper material for the piston but heavier?teazer said:Draw a con rod and piston. Then draw a longer rod beside it - not crazy longer - say an extra 5 or 10mm and now draw the piston in the same position as the first one and see where the pin end up. It moves up inside the piston by 5-10mm to keep the same height. On a clunky old auto engine that's possible but if our pins moved up more than about 1-2mm they would be in the ring pack and even with thinner rings moved as high as practical, there's not a lot of room to move.
What Smokey may have forgotten to mention is that raising the rings closer to the crown increases power. We do that by machining down our pistons and barrels and we get a decent squish plus higher CR plus higher ring pack. But don't tell anyone. It's our secret right?