Hey guys
Just want to know how far out i can port my stock H89 A15 head? Does anyone know how many millimeters i can safely port away?or the demisions of your ported head?
cheers

I wonder if your H89 heads are similar to our H95 A15 heads in the US? The H95 has the heavily shrouded "swirl" oval ports. If the H89 is similar, I can tell you that I tried porting mine and it was looking good until I poked a hole in the shrouded part next to the guide. I was trying to make the port look more like the standard wide open oval port in the H72 head. I thought maybe the extra material added to build up the shroud around the guides was solid but it isn't. There's water in there. Here's a pic of an intake port bowl in an H95 A15 head before porting:




After porting below:




Here they are side by side:




This one is from my H72 head after porting. No shrouding here!




Mike

does anyone have the specifications of there ported head? How much taller and wider can i make the inet and exhaust ports?

Big ports aren't everything

Mine are large but not huge on my H89
I can't find my measurements however

I have gone larger but not huge
I wanted to keep airspeed up

true, ports too large will mess up low rpm airflow. you can also work on matching the ports to the gasket and the manifolds, there is often a good bit of overlap that can't be good for flow at any speed.