Now, 86 degrees (before) TDC (top dead center) is determined
by the angular position of the crankshaft -- which determines
the position of the piston -- at the point the spark plug fires.
This 86 degrees is exactly 4 degrees past the half-way point
to TDC (TDC being the point of maximum compression).
(Ordinarily, the plug would fire only a few degrees before TDC.
Camshafts are not a primary issue in the above definitions.)
Again, in the Joe Cell, perhaps a (chemical?) reaction is
occurring that requires a spark and a DELAY -- to produce the
actual 'detonation point' near TDC, as in an ordinary engine.....
--Bill
At 11:56 AM 12-26-98 -0500, Ken wrote:
>
>I thought on a four stroke engine that every 90 degrees the
>piston goes through a stroke. 4 * 90 = 360? So at 86 degrees
>it is just 4 degrees from bottom?
>
>
>>At 11:49 AM 12-25-98 -0500, Ken wrote:
>> >Norm,
>> >No tangents.... think about it... 86 degress TDC a spark!!!!
>> >That is when the piston is at the bottom of the cylinder!
>> >If you then 'ignite' the volume... it just may 'implode' ..
>> >creating a huge vacuum... to suck UP the piston rather than
>> >an 'explosion'.
>>
>>
>>Wait.... 86 degrees (before) TDC (top dead center) isn't
>>"when the piston is at the bottom of the cylinder" (BDC).
>>
>>Instead, it's slightly after half-way up, when the crank is
>>at right angles to piston travel.
>>
>>Perhaps a (chemical?) reaction is occurring that requires a
>>spark and /a delay/ -- to give actual detonation near TDC ???
>>
>>
>>--Bill
>