Understanding valve seals

MOPAROFFICIAL

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used air into cylinder. Just to be clear the Blue Posi-stop seals are what was on there. I switched to Viton umbrella seals..just didn't take a pic after.
They are sensitive to stem size. Worn out/ under size.. leaks.
 

RustyRatRod

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Although this does not necessarily address your oil consumption issue, I cannot believe anyone else hasn't said anything about it.

Just to get it right in my mind, you said you used different length pushrods in your engine because the valve stems were all at different heights, is that correct? That has to be one of the most difficult and expensive band aids I've ever heard of in my life.

You should have sent those heads back to the shop that did them and had them redo those head and get them right.

Lastly, to your "oil consumption" issue. You're trying to chase oil consumption at 500 miles? For real? If this engine were under a factory manufacturer's warranty, they'd laugh at you and tell you to put enough miles on it to break it in, because IT'S NOT. ....and you're tearing into it to fix a problem it may well not have.
 

70Hardtop

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How did you keep the valves from dropping during seal change??

You can either make sure the piston is up high enough in the bore to stop the valve falling in or else use some tight rubber bands around the stem. Also you can use compressed air and a cylinder hose adapter which are available cheap from Summit and use air to hold the valves up in place. (screw into the plug hole with an O ring seal)
 

pishta

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I'm in the process of replacing these on my mazda. They are metal caps that are POUNDED onto the tops of the valve guides and no amount of force with said cheap no leverage multiplication "valve seal pliers" would budge these bottle caps. I ended up using a modded screw type valve spring compressor to pull these off. After I snugged the jaws on the seals, it took 5 ft.lbs (!) break away to pull these off! 60 in/lbs on a 3/8 stud was almost 800 lbs pressure.
 

MOPAROFFICIAL

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..mOr file the edge off the keeper groove/s
Just putting it out there for the one getting into this...
You need more than a BFH and a socket to properly disassemble cylinder heads.
You ought to have a some kind of spring compressor ideally and at least a file to knock down the valves keeper/lock grooves..or else when you take them out...they will destroy any guides that were still in spec or usable. Stock valves are not very hard or strong, they break and they also distort at the lock grooves. The locks hammer the groove edges outward.

Someone once told me he thought if he turned the valves as he forced them out that it would give a knurling effect...
No... more like a swirly slide for the oil to super hwy to the bowl is all that does.
 
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Bewy

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When I am removing valves that developed an 'edge' from the keepers, I use a small fine tooth file to dress the sharp edge until the valve comes out of the guide freely.
 

MoparLeo

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Like any other job you need 2 very important things, Good knowledge about what you are working on and the proper tool(s).
Probably covered in the Mazda factory service manual just like most manufacturers.

 
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