When I built my last combo I used Manley 24035-16 Teflon valve seals. I have .530 guides and they are the correct seal size. I have about 5,000 + miles on my combo. I started noticing oil on my plugs and tracked it down to the valve seals. About 1/2 of them were broken. I figured there must be a problem with the inner spring hitting them, binding or coil bind. Everything checks out ok. Has anyone ever had this problem with these seals????? Any suggestions????? Thanks Monte

Was the height of the guides cut down to compensate for the teflon seals? Could it be that the retainers are causing the damage? When I cut the guides on my BBC down, I used a set of "checking springs" and made sure I had at least .100" clearance between the top of the seal and the retainer at max lift. Remember that most dual pattern cams have increased duration and lift on the exhaust side.

Like Dave said, about the only thing that break a Teflon seal is interference. These seals will normally work well with dual and even triple spring set-ups. I too, suspect that the retainers are hitting the seals.