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Valve seals
https://slantsix.org/forum/viewtopic.php?t=60116		 Page 1 of 1
Author:  Elivis' Dart [ Sun Sep 04, 2016 10:01 am ]
Post subject:  Valve seals
replaced the umbrella valve seals when I pulled the head. Was very careful and put them on the correct valve. Fel pro seals. Car is burning oil. Lots of smoke on start up. Only 50k on engine. Pulled valve cover and seals are not sealing. They are sticking on the valve and coming to the top. Carefully pushed them down and they immediately go back up when I start the engine.

The valves are not varnished up. 74 225

Is there a break in period? Have put about 500 miles since I pulled the head.

Wisdom is appreciated. Will post in A bodies forum too, sorry if you read this twice and if you have the answer Thank you!
Author:  CNC-Dude [ Sun Sep 04, 2016 12:29 pm ]
Post subject: 
Valve seals may not help unless the rest of the valve train is also in good condition. If the valve stems are worn and the guides also worn out, new seals won't do much with these other components in poor condition. You stated the engine was rebuilt about 50K ago, but what was actually done? Was is a backyard build with just gaskets and incidentals or a professional teardown with newly bored cylinders and new pistons, new valves and valve guides and otherwise a topnotch build. One quick clue to the valves/guides condition is if you can grab the top of the valve stem and move it in any direction and see movement....one or both are worn out and need to be replaced in order for the seal to do its job correctly.
Author:  Elivis' Dart [ Sun Sep 04, 2016 12:49 pm ]
Post subject: 
Thank you for the reply.

The engine only has 50k. No rebuild. The stems appear clean, but the seals do not stay seated. The ride up the the top where the keepers are.

When I put them on the fit very tight. Are the supposed to loose enough to let the valve slide through. There seemed to be no way to get them to snap into place around the guide.
Author:  CNC-Dude [ Sun Sep 04, 2016 1:00 pm ]
Post subject: 
Do the seals have a metal band around them? The kind that seats onto the valve guide requires a tool to do this.
Author:  emsvitil [ Sun Sep 04, 2016 2:16 pm ]
Post subject: 
The rubber umbrella type seal stays with the valve.

Works more like a splash guard than seal.
Author:  SlantSixDan [ Sun Sep 04, 2016 5:20 pm ]
Post subject: 
The umbrella seals are just that: umbrellas. Their job is to keep too much oil from "raining" onto the valve stem/guide junction, while still allowing enough to keep the stem lubricated. The umbrellas are going to ride up like that; that's what they do. It's not a fault; they're working normally. It doesn't mean they "aren't seating", and there is no break-in period on them.

Assuming the head was rebuilt properly (what was done with the valve guides?), I don't think your problem is defective valve stem seals. Did this big smoke on startup just begin recently, or just got worse recently, or...? Does the smoke go away completely once the engine's warm? Or is it runtime-based, and if you warm up the engine, let it sit for a couple hours and then start it again (engine still warm), do you get a bunch of smoke again?
Author:  Elivis' Dart [ Mon Sep 05, 2016 5:36 am ]
Post subject: 
Thank you for the replies.

I had to pull the head for a broken manifold bolt. The engine only had 50K, so I just put in valve seals and replaced the head gasket.

The car is new to me, so I am not sure what it did before. I did not run it too much before I pulled the head because the manifold gasket was blown. It is in great shape and has to have spent most of it's life parked.

The old valve seals, which were hard as a rock, sat down on the head. I get how they work but if they are all the way up by the keeper they are not really doing much. I have never seen an engine (this is my first slant) that the seals ran all the way up the valve stem. They are so far away from the head that they are not sealing anything.

The smoke is on start up, which I assume normally means valve guides - odd for an engine with 50K. Yes, smoke after overnight not for a few hours. It also blows a lot of soot out the back. I have big black circles on my driveway. It is running well and I adjusted the carb with a vacuum gauge. Yes, I adjusted the valves. I may run them again since I have the valve cover off. No oil leaks, but I am going through quite a bit of oil. The smoking is getting better but even my 350 Chevy at 45 years old smokes less.

The car has sat for a long time. I think the first thing I am going to do is simply drive it everyday and see what happens. Cars are made to be driven - it so hard on them to park them.

I have some vacuum line/emissions stuff questions, but that is another thread.

Thank you for reading and all of the help - I appreciate it
Author:  SlantSixDan [ Mon Sep 05, 2016 12:57 pm ]
Post subject: 
Quote:
I had to pull the head for a broken manifold bolt.
Fun :-(
Quote:
The engine only had 50K, so I just put in valve seals and replaced the head gasket.
It's possible you've got a head gasket oil leak into one or more combustion chambers. Have you pulled and examined all six spark plugs?
Quote:
I did not run it too much before I pulled the head because the manifold gasket was blown. It is in great shape and has to have spent most of it's life parked.
High likelihood of stuck rings.
Quote:
The old valve seals, which were hard as a rock, sat down on the head.
Because they were used up. Rubber hardened and shrank, central hole enlarged.
Quote:
I get how they work but if they are all the way up by the keeper they are not really doing much. I have never seen an engine (this is my first slant) that the seals ran all the way up the valve stem. They are so far away from the head that they are not sealing anything.
Again: they are doing enough; that's how every (nonsmoking) Slant-6 was built. You're still incorrectly thinking of them as positive seals, which they are not (and aren't supposed to be). They are still umbrellas. I know it's tempting to want to believe that a cheap and easy item like valve stem seals must be the problem, but sooner or later reality must be faced.
Quote:
The smoke is on start up, which I assume normally means valve guides
Often but not "normally" or exclusively.
Quote:
Yes, smoke after overnight not for a few hours.
And the smoke lasts...a few seconds? A few minutes? Until the engine is warmed up?
Quote:
It also blows a lot of soot out the back. I have big black circles on my driveway.
That's indicative of carburetor and/or choke issues.
Author:  Louise76 [ Mon Sep 05, 2016 2:02 pm ]
Post subject: 
I agree with Dan. Black smoke = carb rich when cold, or...? (Plus some oil too.)
Author:  matv91 [ Mon Sep 05, 2016 2:33 pm ]
Post subject: 
Image
Author:  matv91 [ Mon Sep 05, 2016 2:55 pm ]
Post subject: 
4071006 does fit slants, I think intake 4071003 fits too but not sure. 4095-543 is in the 1980 parts book listed intake valve stem seal. As of 2 years ago dealer could order these parts. This is factory stuff ,stays on head,does not ride up with intake valve. At least when new there is a snug fit to head. Over time the seal would loose grip on head ,and ride up and down with valve , just like the after market seal lExhaust seal does stick to valve not sure. About 2 years ago I put new seals on slant used 4071003 i think not sure.
Author:  SlantSixDan [ Mon Sep 05, 2016 4:00 pm ]
Post subject: 
If for whatever reason you want to have genuine Chrysler seals, 4071 003 is the intake seal and 4071 006 is the exhaust seal—those are the current, up-to-date numbers. But whatever seals you buy from a reputable brand (NAPA Gaskets and Seals, Victor-Reinz, McCord, Fel-Pro...) will be at least equal to the Chrysler items, with less markup in the price. That's because Chrysler doesn't make valve stem seals, and never have. They buy them from the same companies you and I can get them from at retail.

For the third time, your valve seals are not faulty because they ride up on the valve stems. That's how they're supposed to operate. Find and fix the real problem.
Author:  SlantSteve [ Mon Sep 05, 2016 5:16 pm ]
Post subject: 
Like Dan said...the umbrella seals grip the valve stem,not the head. They ride up and down as the valve opens and closes,it's just a shield for excessive oil. Performance engines often have seals that fit onto the head and remain stationary,they work well but aren't necessary on a stock or mild build. To be honest with good guides oil consumption is only slightly increased even if you don't run seals,but when the guides wear then it's a different story. Im not suggesting not using seals.all I'm saying is your problem is likely not the seals,unless your guides are totally trashed,but if that's the case no seal will solve your problem,fix the actual cause.
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