Well, that's what they do. The standard issue "umbrella" type don't stay in a fixed position or aligned with the valve guide boss.

OK, I need the benefit of your experience again, please. I used a small inspection mirror to look at the umbrella seals on some of the valves. On all I looked at, the umbrella is up under the keeper and I can see exposed stem where it goes into the guide. I used a small screwdriver to reach in the spring and push a couple of them down onto the guide. I then ran the engine a few seconds and the seals stayed in place on the head. It can't be that simple, the seals must be working themselves up the valves. What is going on? 

I replaced the seals on another type of V8 engine by threading a cord into each spark plug hole, one by one and compressing it by turning the engine. I used a simple and cheap lever type spring compressing tool that attached to each rocker stud on that engine which unfortunately won't work on a Y-block.



~DJ~ AKA "Bleach"
1956 Ford Fairlane Town Sedan 30K original miles

I feel your pain. You are not alone...

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Even the el-cheapo imported from you-know-where valve spring compressors will do the job. They look very similar to the one pictured. About $10 or $12 delivered, from that auction site. Alternatively you could rent one from an auto parts store. Normally I dislike cheap junk tools, but unless you plan on lots of valve spring work it's tough to justify the added expense for one time use.

Recently did this with my Y block in my truck. I had an eye towards replacing valve springs. These are often overlooked as a source of trouble, they are important and wear out. If the valve springs on your engine are original this is something to think about, they are not expensive. It will run noticeably smoother and better power.

Anyway since I was already "in there" it was a no brainer to replace the valve seals too. I can say that removal and replacement of the springs has a certain hair-shirt element to it with the heads installed. It is a PITA. There is clearance to install the valve spring tool (and remove valve springs) for each cylinder, even under the stock single pot brake master cylinder. Be careful not to lose the valve keepers across the garage, or drop them down the oil return passages. A mechanic's magnet tool is your friend here. I'd seen movies like this before and knew it could cause trouble, so I took my time. Took me several hours to do all 16, including measuring/shimming the assembled valve height to stock specs.

Keeping the valves from dropping into the cylinders (then you WILL be removing the heads) can be done a few different ways. Applying shop air is one method. What worked great for me was to take a few feet of rubber vacuum hose and tie a knot in one end. Stuff it in the spark plug hole up to the knot. Roll over engine by hand until you feel resistance. The valve springs can then be removed/reinstalled for that cylinder without the valves dropping down into the engine.

Naturally, I also removed the rocker arm shaft assemblies and ended up replacing those as well, and the rocker arms themselves, and all of the pushrods for good measure. Valve stem seals cost $5, but when the springs, rockers, rocker shafts, pushrods get thrown in there it growed. Lucklily I somehow stopped myself from rebuilding the entire engine.

ther is a tool available at most parts stores that makes  it easy to chang  valve seals. cost in canada was 30.00. just be sure to have the cal youare working on is at TDC.you should have a decent magnet. check the intake  valve first as it would be the most likely culprit. before starting use a good small flash light and look at the valve seal. possible that asembler  never installed 1.get a good manual and it will walk you threw.

Maybe Consider -

Danaher Tool Group KDS3271 Universal Overhead Valve Spring Compressor

• Designed to remove valve springs on cars and light trucks
• Features a removable handle that allows the use of a 5/8 inch socket or wrench in confined areas
• Backed by a lifetime warranty

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I don't know how the engine was broken in, or the type seal on it now. I'll muddle through replacing them, though. I've been wrenching on cars as a hobby since I was a teenager (75 now), built a few engines and cars, so I'm not completely lost. I see different types of valve spring compressors available. Can someone give me a picture of one that will work well for this application?

GOOD INFO HERE!

The quality of the seal is paramount. Use quality/proven parts.

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What type seal was the head assembled with?

http://www.felpro.com/technical/tecblogs/valve-stem-seals.html

Regardless, the valve(s) seal can be serviced on the cylinder head with special service tools.

You are using a lot of oil. Was the engine broken in properly or/and does the ventilation system work? Leakage?

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