Port Chamfer

[SamLS]

What is the consensous on the proper type of port chamfer on a Nickasil cylinder. .5-1.5mm x 45deg. I have seen anything from 2mm radiused to 45 deg by 3mm to about 15 deg by 6mm. By deg I mean relative to the bore axis. Thanks

 

[Guaryzzzpode]

I would stay with the normal 0,5mm 45°, specially for the transfer and boost ports. You could change for the exhaust, but only if you need it, like when you have widened the port so it's easier on the rings.

 

[cujet]

It also depends on the port size and cylinder size. A single 70% width exhaust port on a 500cc single will need a better chamfer than 0.5mm. I like to round my chamfers.

Chris

 

[EricGorr]

The manufacturers' standard is .5mm on transfers and 1mm on intake and exhaust ports.