Valve Seals on 401/425?

[Guest]

I'm rebuilding my '64 425, and noticed that, in addition to hardened valve seats (both intake and exhaust), the previous owner installed valve seals in the early 80's (and he probably told me why, but he died ten years ago). I know the hardened seats are for unleaded. I assume that the engine did not come with valve seals since they are not mentioned in the '64 service manual. It appears that the guides are bronze.<P>It looks like the [parts of the head sticking up with hole in it that springs are around] were machined on the OD to have these seals placed over. A few of the whitish plastic seals are broken. I am wondering whether they are realing doing anything, except perhaps slightly reducing the oil consumption. I am thinking of removing them all, under the assumption that the valves will get a bit more lubrication. In addition, I don't know what parts they actually are.<P>Has anyone else seen valve seals installed on nailheads like this?<P>-Rod

[Guest]

I believe the '66 401/425 used seals and that is what you use on the earlier engines. They must do something or Buick wouldn't have installed them.

[brad54]

I've heard (though I don't know where or when it was) that NailHeads didn't use valve seals. At least the early ones.<BR>What the seals do is keep oil from dripping down the valve stem into the cylinder. It sounds like you've got Perfect Circle seals. They are aftermarket machine shop installs, but good ones.<BR>I know one builder who puts these seals on his intakes, but won't put seals on the exhausts. He says the exhaust valve runs hotter, and he'd prefer that a bit of oil get between the stem and the guide. This prevents the valve from sticking, siezing, burning the stem, wearing, etc. The price is sometimes a puff of blue smoke on start up, when the oil that's run down the valve burns. Remember that the intake side has a cooler charge running past it, where as the exhaust has a hot gas going out it all the time. It should be noted he's a Mopar builder, but it makes sense to me. He's built a lot of engines, they all last a helluva long time, and they make great power. <BR>-Brad