[joey112]

I got the cylinder/head back from the machine shop along with a new 67.5 wossner piston. I'm in no rush to get it back together since my current engine is still running good so I decided to check the squish and it's .0750 using solder with a .010 metal head gasket and the piston is just below the deck at TDC. Does that squish sound about right for an OEM setup that hasn't had the head or cylinder deck milled? I'm going to do a UCCR just to do it but I'll be using 110 since I don't want to take a chance with pump gas anymore. My current engine in the trike as far as I know is also stock with 66.5 bore and a .010 gasket and cylinder cranking compression is 210.

 

[TrailBurner]

I recall .075 is stock. With my head designed to accept 108 cam2. Think it was 180psi. With .040 squish. Copper gasket. 12.7
There's a lot more to it than less squish equals higher octane. What was done to the head n port heights.

 

[joey112]

I don't know if anything was done to the port heights when I just had it bored to 67.5. All I know is he bored it, provided a Wossner piston, chamfered the ports and milled the head flat. I started it up on Sunday and rode it around and so far it runs good. I bumped the pilot from 45 to 48 and main from 155 to 160 and it's a bit rich but once the rings have some more run time I'll mess with leaning it out if needed. I did a leak down and found and fixed a few leaks before installing into the frame.