Adjusting valve clearences?

[flynfrog]

i believe the highest piston speeds come from the NHRA top fuel (mountain motors)

indy and F! are actually pretty slow since they have almost no stroke

[DaveKillens]

Piston speed is used as a measure of how brutal things are for the engine. The higher the speed, the shorter the estimated lifespan of the engine. Remember, a piston has to go to top dead center, then accelerate downward to bottom dead center, then back up, and over and over. When you consider that your engine's pistons make the trip up AND down 9,000 times a minute, that's a lot of stress on the crankshaft, connecting rods, and piston. That's why pistons are usually made of aluminum, to lower mass and the forces of all that harsh acceleration.
http://www.csgnetwork.com/pistonspeedcalc.html
At a 77 mm stroke of your B18C5 engine, your piston speed is 23.1 M/sec at 9,000 RPM, which is right up there.
http://en.wikipedia.org/wiki/Mean_piston_speed

Edit.. stroke may be 77.4 mm, I'm not 100% sure on either.

[djones]

These are the specs:

ROD LENGTH: 5.429”
STROKE: 3.433”
BORE SIZE: 3.189” (81MM)
COMPRESSION HEIGHTS: 1.190”
DOME HEIGHT: .070”
WEIGHT: 310 GRAMS


Can anybody work out how much the piston will weigh at the end of its stroke?

Also, what stroke (roughly) does an F1 engine use?

[Strax]

Hmmm!

For maximum performance (especially in the VTEC optimum RPMs) you must shoot for the tight end of the specs. This will act as an increase in the duration of the camshafts (since the valves now will open sooner and close later). The two ends of the valves clearance (0,17 vs 0,19) will account approximately for a 4-7 degree difference in cam duration.

In the real world, it is not that easy to achieve the same number for each valve. What you can do is to try to be on the tight side (0,17)