Finding port timing numbers

[Chainsaw Jim]

Hmnn ............ a deleted post eh ???

Degrees does throw people off, but once you figure out how to use a wheel correctly, its just a matter of going through the motions and checking to be sure.

Like was already said, the length of the stroke and where the measurement is taken determines how far each degree actually is ................ but the wheel reads what the wheel reads no matter what the stroke distance is or where the stroke is being measured

It sounded snarky and insulting so I dumped it.
I use a degree wheel for ignition timing, but I measure port timing with a tape and calipers so I don't get lost when the jug is in my hand.

 

[Moparmyway]

I measure port timing with a tape and calipers

Thats gotta be tough .............. can you do that in a 30cc cylinder ?

 

[Grits & Gravy]

I've always cut the squish go make the compression I want first, then cut the base to set my squish clearance.

Right now I'm getting ready to change the way I do things.. I'll be CNC machining the entire chamber not just the squish.

I've never really worried to much about what the numbers were stock.

 

[Chainsaw Jim]

Thats gotta be tough .............. can you do that in a 30cc cylinder ?

I use the caliper to measure the openings from the outside. I use an old piston and a fine sewing needle to mark tdc and bdc on the piston itself so I can use it for reference if I need to. It's a different approach since I taught myself. But I've only messed up once and that was with my 372xpw freeporting. I did that because I was an idiot and didn't mark my line before grinding.

Do I have to do it in a 30cc cylinder? Because I personally have no reason to even try.

 

[Moparmyway]

Do I have to do it in a 30cc cylinder? Because I personally have no reason to even try.

Haha .............. no, I had to do it in a 30cc cylinder.

My calipers would not fit down into the bore, and I wasnt able to measure the cylinder side opening of any port ........... so I decided to install/remove the cylinder about 60 times to get it right, you know grind a little, install cylinder, check numbers, repeat for each port.

Then I saw the ring trick here on AS and did it with one of my 70cc saws.
WOW, big bore compared to that little 30cc one !!