This chart is courtesy of Nelson King. I tells you how much material should be removed from a port to go from timing "A" to timing "B". If you are not certain how to use this chart, ask first. Also you should chose a few degrees less than the actual target, do your cut and check the actual result and continue from there.

* I have updated this picture to a better quality one that should print out better.


Download the original (larger size) here: www.modelgasboats.com/Resource...ming_Chart.html

Nice chart , I'll have to tell Nelson thanks for getting it out next time I see him. Lots of great info in their,

Very nice !

The unit is inch ?
I prefer to check as the title refers to engine stroke and rod length in mm.

@+ Gael.

Is there a chart that shows diff timings per perfomance setup? Would like to see more on this. RUSS

The units are in inches, yes.

I don't know of any chart that correlates the timing numbers to performance...that would kind of be impossible I think.

Marc. When will the chart be available again. As for what I was asking before, I gues I am wanting to know what timings go hand in hand. In other words what intake port timing goes with exaust port timing, and then what transfer port timing goes with the other 2. Porting is somewhat simple, but the timing is what can be and is confusing as to what makes power. Thanks, RUSS

Sorry Russ,

Had not noticed that the pic was lost in the move.

I have re-uploaded the chart and added a link to get the original from the resources section. Here is the link: www.modelgasboats.com/Resource...ming_Chart.html