twhitaker Posted January 21, 2005 Posted January 21, 2005 Ah, but the Ariel is but a pair of Triumphs siamesed together with a pair of cranks and would fit into the transverse category. The Guzzi museum has a V4 prototype on display, another transverse.
Admin Jaap Posted January 21, 2005 Posted January 21, 2005 How about this Goose with L shaped engine?
Martin Barrett Posted January 21, 2005 Posted January 21, 2005 As Al said one part relates to the configuration of the cyclinders and the other relates to the poistioning of the crank ie - Holed, on the bench waiting for parts
Steve S. Posted January 21, 2005 Posted January 21, 2005 "In 90 degree form, perfect primary balancing is obtained by counterweighting 100% of one piston plus the small-end. The unwanted centrifugal force from this weight at 90 degrees position from No. 1 cylinder exactly cancels out the primary inertia force emanating from No. 2 cylinder and this applies to all positions of both pistons. The secondary forces must, however, be taken into account, because they can be large enough to be serious in a big engine." He goes on to state that these secondary forces (less force but higher frequency) act in the horizontal plane, which on our bike, means they act across the frame, side to side, not front to back. I Think Mr Irving has forgotton to consider that the speed of the piston in a recip engine doesn't change in a sinusoidal fashion. The acceleration rate is higher through TDC than through BDC because the crankshaft angle at the center of the stroke isn't at 90 degrees. And the shorter the rod, the greater the disparity. It's cool how there are two simultaneous topics in this thread!
Flatland Dan Posted January 22, 2005 Posted January 22, 2005 I've had a head cold for a couple of weeks now. Is that a sinusoidal problem? Ba-dum-ching. JRT is in the lounge all week. Don't try the veal, I have already sneezed on it. Beer is good, Dan.
Frank Posted January 22, 2005 Posted January 22, 2005 "I Think Mr Irving has forgotton to consider that the speed of the piston in a recip engine doesn't change in a sinusoidal fashion. The acceleration rate is higher through TDC than through BDC because the crankshaft angle at the center of the stroke isn't at 90 degrees. And the shorter the rod, the greater the disparity." No, he hasn't forgotten. In Phil Irving's book, this fact is discussed earlier in the chapter: "The force required to start and stop a piston is at a maximum just at tdc and if the conrod were infinitely long, a force of the same value, but opposite in direction, would be required to perform the same function at bdc. The piston would then possess what is know as simple harmonic motion but this condition never exists because, for reasons some of which are obvious and some are not, the conrod has to be a lot shorter than infinity and is usually somewhere around four times the crank radius or twice the length of the stroke. Because of the angularity of the rod to the centre-line at or near mid stroke, the points at which the piston attains its maximum upward or downward velocity, assuming, as is usual, that the cylinder is central and not offset, occurs not at the 90 degree crank position but at about 76 degrees before or after tdc, the precise position depending, or course, on the conrod/crank ratio. This means that the piston has 152 degrees of crank rotation to get from maximum speed down to zero and back to maximum during the upper half of the stroke, and 208 degrees to go through the same sequence during the lower half; the upward inertia force must, therefore, be greater than the downward force" With simple harmonic motion, the inertia forces can be represented graphically on a crankangle or time base, as a symmetrical sine wave of which the maximum values are given by tahe expression 0.0000142WN(squared)S where W = weight in lb, N= rpm and S=stroke in inches. The effect of the necessarily short rod is to modulate this symmetrical curve by superimposing on it an infinite number of other harmonics, forming a Fourier series of increasing frequency and decreasing amplitude. Of these, only the secondary harmonic of twice the frequency and one-quarter the magniturde of the primary need concern us here, as the higher harmonics assume any importance only in engines with six or more cylinders." ...................................................................................................... "Arithmetically, the effect of a rod with a comparatively short length is to increase the primary force at tdc and reduce it at bdc by the factor R/L where R is the crank radius and L is the rod length (both of course meassured in the same units); this factor can for our purposed be taken as 1/4, the slight differences encountered in practice having only a minor effect" This book although dated is part, is a great reference. Frank
Lex Posted January 22, 2005 Posted January 22, 2005 OK, so I'm the dummy who got it backwards but the inline Vs. transverse is simple. If the crankshaft is in line (parallel) to the wheelbase the engine is inline. If the crankshaft runs across (is transverse to) the wheelbase the motor is transverse. The number of cylinders, the orientation of the cylinder(s), etc. is irrelevant. BMW actually built an inline single back in the sixties. Why is this important? So we all know what we are talking about! Lex
helicopterjim R.I.P. Posted January 22, 2005 Posted January 22, 2005 Don't say anything bad about Solex or Tex will have yer guts fer garters!
helicopterjim R.I.P. Posted January 22, 2005 Posted January 22, 2005 Per favore Antonio come è il mio Italiano? Il mio amore Marie dice ciao anche.
antonio carroccio Posted January 22, 2005 Posted January 22, 2005 Jim.......................................................vaffanculo! Dai un bacio a Marie da parte mia. Just kidding pal.
antonio carroccio Posted January 22, 2005 Posted January 22, 2005 Don't say anything bad about Solex or Tex will tell Jaap 41601[/snapback]
twhitaker Posted January 22, 2005 Posted January 22, 2005 OK, so I'm the dummy who got it backwards but the inline Vs. transverse is simple. If the crankshaft is in line (parallel) to the wheelbase the engine is inline. If the crankshaft runs across (is transverse to) the wheelbase the motor is transverse. The number of cylinders, the orientation of the cylinder(s), etc. is irrelevant. BMW actually built an inline single back in the sixties. Why is this important? So we all know what we are talking about! Lex 41589[/snapback] So Ducati and Moto Guzzi got it wrong when they called their bikes in-line and transverse, respectively?
twhitaker Posted January 22, 2005 Posted January 22, 2005 OK! Now what the heck is this? 41593[/snapback] It's a radial. Bet the tire is a bias ply.
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