Draglist.com Drag Racing

Thanks Bob!

Ok, there is a point in time when the piston is stopped completely, as I said, At TDC exactly and BDC exactly. Had one friend, check his shortblock with a dial indicator on a piston and a degree wheel, we figured the piston may be stopped on his deal for 3-4deg. Wrong! He checked it 15 times and always came up 1deg, or a little less, need a ten thousandths indicator to figure any closer. Then go from there till ya run out of proper measuring equip.

Another friend says, on a 4in stroke, 5.85 rod engine at 8,000rpm,
It's stopped, approx.. .000002083sec.!!

He said, you can inch down and still only see 0 stopped at 0degrees.

But it HAS TO HAPPEN some point in time. I agree, but it gets pretty involved figuring, cause once you think you have it, then figure rod clearance, oil film strenght ect... Forthe sake of arguement, we'll just say that ,


THE PISTON IS NOT STOPPED VERY LONG I'm done.

So since it stops twice on each revolution....000002083sec. here 000002083sec. there. before U know it...........it reeeealy adds up.

if you could really get a slow mo video you would see the piston standing there shuffeling his feet waiting to change directions

Probably look like Buddy Epson!

Ya gotta admit, Buddy was a good shuffler, him and the black guy in that Shirley Temple movie, where they were goin up and down the stairs!!!

The answer to your question is: Zero seconds. The "still" position of the piston is no different from its position at any other rotation angle. The connecting rod is merely an extension of the crankshaft throw.