Does anyone test MSD total loss ignition modules? (P/N 4272)

freestylegeek

waiting...
Location
Grand Rapids, MI
Why do you say this? A stroker's geometry doesn't inherently change ignition timing at all. Other things(port timing ,squish, comression,etc..) might require a substantially different timing curve, but not simply the fact that it's a stroker. A given stator set at the factory location will produce the same timing whether the stroke is 68mm or 76mm.:thinking:

The piston speed and dwell time are different on a stroker (especially with long rods). The piston gets (closer) to TDC sooner, hangs out there longer, then moves away faster. Therefore, the f/a mixture is squeazed quicker, held under compression longer, then expanded faster. Firing the plug at 30º BTDC on a stock stroke, the mixture is not as compressed as a stroker, and the flame front will move at a very different (slower) speed.
 

crammit442

makin' legs
Location
here
The piston speed and dwell time are different on a stroker (especially with long rods). The piston gets (closer) to TDC sooner, hangs out there longer, then moves away faster. Therefore, the f/a mixture is squeazed quicker, held under compression longer, then expanded faster. Firing the plug at 30º BTDC on a stock stroke, the mixture is not as compressed as a stroker, and the flame front will move at a very different (slower) speed.


That is all technically true. My point was that the actual igniton timing doesn't physically change because it's a stroker. Also, most builders use very similar curves for strokers and stockers. The big changes are primarally due to fuel choice and desired performance.
 

SuperJETT

So long and thanks for all the fish
Location
none
That is all technically true. My point was that the actual igniton timing doesn't physically change because it's a stroker. Also, most builders use very similar curves for strokers and stockers. The big changes are primarally due to fuel choice and desired performance.

You'd be surprised at how different the curves are he's had recommended to him on this engine.
 
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