Size of port with 1.77 intake valves

[gnnovas]

I'm doing the valve job on my own heads and need sugestions on what to do with the ports under the new valves. I've cut the seats out to the correct size for the valve and now there is a large taper under the valve. I used a 60deg stone to open the port but it looks as though there could be more done. Any sugestions would be appreciated

Ken
87 GN

 

[TA2SLOW]

Well if your talkin seat diameter, I like to see 90-92% seat to valve diameter on the intake and 88-90% on the exhuast side. Thats what I do for N/A heads, you turbo guys might like something different.

 

[gnnovas]

The area I'm talking about is between the seat in the head and the bowl area in the port.

Ken
87 GN

 

[TA2SLOW]

Originally posted by gnnovas
The area I'm talking about is between the seat in the head and the bowl area in the port.

Ken
87 GN

Yeah thats what im talking about also, the throat and seat diameter.

 

[UNGN]

A throat cut of 85% of 1.77 (1.50 inches) should keep you out of the water and take a lot of the taper out, you can do probably more than this to get closer to TA2SLOW's numbers, but 1.50 is a safe number.

 

[gnnovas]

Thanks for the info guys. This helps to keep me out of water.

Ken
87 GN