If you are running heads with 11/32” stem valves and planing on using this type of seal as in my picture then note that you need to check them for size. here’s the back story. A few months ago I received a disassembled set of heads to port. For a near fresh motor the heads chambers and valves showed bad signs of excess oil usage and the owner said he did see signs of smoke out the tail pipes, but not what he called a strange amount of oil usage. I told the owner that the signs of oil on the back side of the intake valves and in the intake bowls looked like a classic valve seal issue. When the owner took the heads back home he assembled them with the same type of seals bought from the same supplier he used during the previous rebuild. He then gets the motor up and running again and has the same tail pipe smoke issue once the oil and the valves get warm enough. Mean while I have another set of heads done and I then need seals . I was at a machine shop the next to pick up a block and asked if they head a set of these same type of seals I could buy . The shop sold me what they had just got in stock. so I get home and open the pack of seals, think about what’s been going on with this other guys motors and I check these new seals with the same type of used ones I had tossed in the trash can. So I found that the used seals checked in at .312” ID, but the new seals where way bigger, as in made for 3/8” stem valves, not 11/32” From this it would seem that this guy purchased seals twice that where packaged wrong and so did the machine shop and in turn me. If you have these type of Viton seals for use on 11/32” valves please check them because who knows how many are boxed wrong .
Another great example of very poor QC or NO QC checks. I see this occuring in so many automotive parts in the last few years.
