How much to you know about engine technology

Lynnmor wrote:

45Ricochet wrote:

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

Many gasoline engines spark before TDC when starting, some small engines have fixed timing that is BTDC.

Never could find the spark plugs in a Detroit diesel. :?

Very true. the only time they fire ATDC is on the older hand crank cars with the timing adjuster in the middle of the steering wheel. you would turn it to ATDC when starting so you didn`t lose an arm or have the crank smack you in the face! after it started you then turned it to BTDC. when electric starters came out the manual timing adjustment went away and it was fixed. they slowly went from 0-2 degrees BTDC in the very early years to 7-10 degrees nowadays. no car that I know of puts timing to ATDC when starting.

I`de love to see that site explain how OBDII systems work! :E