Forever isn't as long as I thought

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07-03-2018, 05:21 AM
55 Tony

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Forever isn't as long as I thought

These umbrella seals where going to last me "forever" according to the guy who did the heads. Any idea what happened to them? They are not hardened or cracking, they are very flexible and hard to tear. I'm not removing the heads and having them cut to hold positive valve seals, so I'm installing the old fashioned umbrella seals that I got with a gasket kit from the rebuild. They worked OK before.

Now that I got your attention, any tips on how to get the valve spring off of #8 exhaust valve without cutting a hole in the firewall? (BBC) #7 intake was a challenge but I got it using a spring tool that looks like a special crow bar. It was cheap so I'm thinking of cutting it and welding it so the long end is at an angle and misses the firewall. Yes, the more I think of it the better that sounds.
07-03-2018, 06:01 AM
markm

Part Number: 555-80531 From Jegs
07-03-2018, 07:01 AM
55 Tony

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Quote:

Originally Posted by markm

Part Number: 555-80531 From Jegs

I have one of those. No go. The knob hits the firewall and it kept popping off the spring. Took my cheap cheap tool and instead of cutting and welding, I elongated the pivot hole so I could cock it sideways some. Coming apart wasn't hard but putting it back together it kept wanting to twist so I couldn't get the keepers on then I noticed a small bolt in the firewall. Pulled hard on the tool, cocked it past that bolt and hooked it on, took a visegrip on the tool at a right angle to give me leverage to twist it and I got it back on again. It would have been almost easy with 3 hands. Got them all done.

Still what happened to the old ones is a mystery. When I first removed a cover and saw pieces of them, I thought they would be hard and brittle, but they aren't at all. Maybe flexing at the top eventually broke them and the rest got chewed up coming out of the springs? They are so flexible I wouldn't think it would happen but something happened.
07-03-2018, 07:12 AM
markm

You must not be between 1.5 and 2.25 forward.
07-03-2018, 07:46 AM
55 Tony

Quote:

Originally Posted by markm

You must not be between 1.5 and 2.25 forward.

No. "Stock Position".
07-04-2018, 06:55 AM
55 Tony

The old style umbrella seals I put in seem to be working well. No puffs of blue smoke on startup. That was getting bad, sometimes while idling also.
07-04-2018, 10:10 AM
chasracer

Off the cuff, I would say spring retainer interference got the old ones. I have one of the knob style spring compressors which works okay since I ground off the fingers and welded a large nut to the top of it.
07-04-2018, 10:24 AM
solidsguy

Quote:

Originally Posted by 55 Tony

Still what happened to the old ones is a mystery. When I first removed a cover and saw pieces of them, I thought they would be hard and brittle, but they aren't at all. Maybe flexing at the top eventually broke them and the rest got chewed up coming out of the springs? They are so flexible I wouldn't think it would happen but something happened.

It could be that the top of the seals were getting smashed between the retainer and the top of the guide boss. It would be a hard thing to check for it though.

Sometimes even PC seals can be disappointing. I've had them pull off the boss and ride up and down on the valve stem inside the spring before. It's enough to piss you off given the money, work, and time it takes to get the "better way" done.