So I started pocket porting on my 78 large log head. I've followed the pics from the Performance Handbook, where it shows Gary Kitchens progressing nicely... What it doesn't really show that well is if the valve guide bosses were completely removed. The text states that they can be reduced or removed, but does that mean totally remove them to the roof of the port? I've done this on the #1 port and it looks a whole lot bigger, and have smoothed to about the same ID as the valve seats. Now, to my undereducated eye, this looks like a good job as far as improving exhaust flow... Pretty much no restrictions now in that exhaust port. From what it looks like, if you stay relatively within the area of the boss, you should be fine and theres enough lenght up above to support the valve stem adequately (i guess).
Have I gone too far? My intention is to run the SI portflow valves, which I think have a little swirly at the valve stem base with a header and 2" exhaust and a direct mount autolite 1.08, 1.14 or a holley 350. Currently running a comp cams 260 with adjustable rockers and stock 65 head and block, see sig.
Assuming I'm still OK, and havent just trashed this casting... how far can I take the intake valve guide bosses down? All the way to the roof? Just smooth and contour? I ain't scared... It's just time and abrasives for me right now.
Figured I'd poke in here to ask the questions I shoulda asked before firing up the die grinder. Kinda shoot first and ask questions later kinda day. Like we used ta do before the days of the internets. I'd be all done and no guide bosses anywhere by now!!
Thanks,
Perry
Have I gone too far? My intention is to run the SI portflow valves, which I think have a little swirly at the valve stem base with a header and 2" exhaust and a direct mount autolite 1.08, 1.14 or a holley 350. Currently running a comp cams 260 with adjustable rockers and stock 65 head and block, see sig.
Assuming I'm still OK, and havent just trashed this casting... how far can I take the intake valve guide bosses down? All the way to the roof? Just smooth and contour? I ain't scared... It's just time and abrasives for me right now.
Figured I'd poke in here to ask the questions I shoulda asked before firing up the die grinder. Kinda shoot first and ask questions later kinda day. Like we used ta do before the days of the internets. I'd be all done and no guide bosses anywhere by now!!
Thanks,
Perry
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