45 degree seat width on small valves

[vwchuck]

Do any of you guys run narrower than the standard .060, .050 inch 45 degree seat width on small valves? Like in a 4 or 5 valve per cylinder head?
When I do my 5 valve head it hardly has any 30 or 60 degree width.

[cgarb]

I would go thinner, most multi valve heads have relatively low spring pressure. Not like your going to deform the seat from solid roller spring loads. I would think the worst thing that could happen would be the valve could overheat, that contact area helps pull the heat out of the valve. I can't see .020" less seat width making a super huge difference. Maybe I'm out to lunch, but I repaired a valvejob on a ATV 4 valve head once and it had the factory cut valve seats in the head that have been run and they were around .030" wide. It was run a long time with the valves adjusted tight and the valves we're beat up. I didn't have a pilot small enough to grind the seats so I was able to chuck the valves and regrind the seat angle. I gave them a lap with some clover compund and put it back together. My buddy is still running it today, that was better than 10 years ago.

[Erland Cox]

I use 0,050" even on smaller multi valve heads.
I have seen that the valves will not last with narrower seats.

Erland

[vwchuck]

Erland do you put in a thicker seat so that you can get a good 30 and 60, 75 cut on them to aid in airflow?

[4vpc]

Seat width is a ratio or a % of the diameter so i'm not sure what the issue is here? If you don't know it i'll dig it out and post it up.