Stupid questions on DD 2 stroke injectors
 

Stupid questions on DD 2 stroke injectors

Started by bevans6, May 04, 2010, 12:57:07 PM

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bevans6

Why is it called "timing" the injectors when what you are doing is setting their relaxed height?

If the correct setting is 1.460", what would happen if you set it at 1.480" or 1.5"?  More fuel, less fuel, same amount at a different point in the cycle?  Can you advance/retard the timing based on this setting?

If you are running "advanced" timing, the cam timing is advanced relative to the crank shaft.  That would mean the injectors inject earlier, and the exhaust valves open earlier.  Presumably the earlier injection means there is more time for the fuel to burn, hence you can inject more fuel, hence more power.  Is that basically it?  Does opening the exhaust valves earlier have anything to do with it, or irrelevant?  I guess you close them earlier too, and so start to build compression earlier.  That would have the effect of increasing the dynamic compression ratio, leading to being able to inject  more fuel, perhaps?

TomC's thing on HP made me think, which is always a dangerous move...

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia