How much to you know about engine technology

travelnutz wrote:
Timing advances to before TDC as the RPM's increase. However, as far as technical/technology being the question, for the engine to even start to run, the actual spark must occur after TDC and into the combustion stroke or the engine would run backward. Pre-ignition would occur! Think about it!

Very common with a 1970's 80's Detroit diesels in OTR tractors. I ran one backwards once in San Francisco after a picking up a load of Best Foods Mayonnaise. Heavy load.... HUGE hill.... Wrong gear :E