Valve seals popping off seats

[dwh4784]

What would cause valve seals to lift off of their seats? My friend's car referenced in the thread linked below with the smoking problem seems to have an issue with them. After swapping turbos and seeing no change in the smoke problem we moved to valve seals. When changing them we noticed three were riding way up the valve stem. Hoping that was the golden ticket we changed them all and started it up and let it idle for quite some time. No smoke! Well, after driving it around it started smoking again, and looking at the seals there are three that came up again. What gives? Is there any obvious way to determine if the car has an non-turbo head/valves in it?

http://www.turbo-mopar.com/forums/sh...ad.php?t=47925

[89ShelbyGuy]

How are the valve guides?

[Turbodave]

Externally the Turbo heads usually had the letters "TS" stamped on them (86 and newer cars with the 782 head).

As far as the seals coming off, are the guides dropping down maybe? A loose valve guide would do that.

[dwh4784]

He pushed them all on so I don't know how tight they were, but he said they all fit pretty snug. If the guides were loose would they move up/down or side to side?

We were just wondering if some shade tree mechanic might have installed the wrong head/valves causing them to not completely close and get blown off with compression/boost. The head is not an original casting.

[turbovanman²]

The valve seals aren't designed to sit on the valve guide so what you have is normal.

It could be dropped guides, bad rings.

http://www.turbo-mopar.com/forums/vb...&articleid=180

[OmniLuvr]

ive also had a problem with the guides lifting, the machine shop put non turbo exhaust valves in, once the valve opens it gets hot and swells, when it tried to close, it lifted 2 of the guides on my head

[puppet]

They screwed up the stem/guide clearances then or didn't check it.

The seals snap on top of the guides ... takes some effort sometimes. If the guide is dropped that far, you won't be able to fit a seal. Bad intake seal will make an egine smoke ... exhaust side not so much. The pressure in the exhaust usually moves oil up and out of the guide. If the clearances are tight (exhaust side), the wiping effect of the seal will clear all the lubrication off the stem and then it's possible for those valves to sieze. You need some oil here. I've seen engines run without seals on the exhaust side. With the right clearances there are no issues.

[turbovanman²]

They screwed up the stem/guide clearances then or didn't check it.

The seals snap on top of the guides ...

Hahhaa, whoops, thinking of another engine,

[OmniLuvr]

when my guides lifted, my tona smoked like 3 packs a day, the build up of oil in the two exhaust ports was crazy, they were half the size, bad times...

[dwh4784]

Looks like he's gonna try a known good turbo head and see how it goes. Thanks for the replies!