906 casting vortec heads: quick question
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 952
Likes: 44
From: NC
906 casting vortec heads: quick question
I was looking in the archives today and saw that someone mentioned the 906 vortec head doesnt flow as well as the 060 and 062s. I was wondering how much worse the 906 flows than the other two. The heads I am putting on my vette have had the valves back cut 30 degrees and have had the sears reground. I did not do any bowl polishing on them. I read that the 060s and 062s flow about 170cc. How much less are the 906s?
Thanks
James
Thanks
James
4th Gear
Joined: May 2006
Posts: 4
Likes: 0
ive heard the flow numbers are the same. the rumor that the 906's flow less is because some of them came with a pressed in exhaust seat that jumbles up the port. but those only came on 3/4 and 1 ton trucks the 1/2 ton trucks got standard seats at least my 906's have a standard hardened seat so if yours have the seat insert thats what all the guff is about
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
The earliest 906's have huge exhaust seats that protrude well into the port but the later ones aren't nearly as bad. A good machinist can cut most of the excess out without compromising the valve job. A bigger concern is the ridge in the exhaust short turn - it's big and sharp. That's an easy fix with a Dremel or die grinder, just takes a few seconds per port. Personally, I'd rather have pressed-in seats so I don't have to count on fuel to provide good enough lubrication to keep from pounding the seats out, resulting in a junk head or dropped valve.
