TV175 exhaust port- a port too far?

[bristolmod]

playing around with a TV175S3 barrel

The exhaust port measures 37.0 mm from the top of the barrel to the upper edge of the port.

The lower edge of the port is 62mm from the top

The width is 42.6mm (as a chord- i.e. across the piston, not around its circumfrence)

Too big? Will be running on a 22mm carb and 42mm clubman?

Any thoughts Gents?

Chris

[J1MS]

playing around with a TV175S3 barrel

The exhaust port measures 37.0 mm from the top of the barrel to the upper edge of the port.

The lower edge of the port is 62mm from the top

The width is 42.6mm (as a chord- i.e. across the piston, not around its circumfrence)

Too big? Will be running on a 22mm carb and 42mm clubman?

Any thoughts Gents?

Chris

I make it close to 68% exhaust port width. You would need wire rings to span the gap
On a 58mm stroke crank with a deck height clearance of 1mm at TDC it would give an exhaust timing around 170 degrees. Which I think is ok for a 175.
But at BDC there will be a piston to port clearance of approximately 3mm this may cause extra heat at the piston crown at this point, which is not really a good thing

[soosh]

Depends on the shape of the exhaust port,you can get away with it still with standard rings.