Replace your valve stem seals on the cheap!!

[Anonymous]

I had a problem with smoky startups, smoke on the overrun etc as well as high oil consumption - for a long time I was waiting for the engine to die but then diagnosed it as valve stem seals after a bit of web research.

It took a while before I got up the courage to takle the job, my biggest worry being the idea of pressurising the cylinder to hold the valves in place...most sites and manuals suggest making an adapter to screw into the spark plug hole which is pressurised via an air compressor - I didn't have a compressor handy and was also worried about all the warnings about if you push down on the valves at all you run the risk of dropping them into the cylinder, so I tried an alternate approach I read on a different page - cheaper and, now that I've done it, I reckon much safer - you buy yourself a nylon clothesline type rope, feed that into the sparkplug hole (lots of it!!) and then wind up that piston until it compresses the rope against the valve heads - sounds shonky but works great!! Also, on one or two valves that had sticky colletts I did end up pushing the valve off its seat but because of the nylon rope you can feel it spring back up again - this would have been a disaster using the air method.

The other thing I needed was a valve spring compressor - I made one myself but I wanted alot more control than the typical lever ones you see around the place - the one I made uses a screw thread setup to push the spring retainer etc down - this allows you to leave the spring compressed at any height you need, with no chance of it moving. The tube that pushes down on the valvespring top also has a `window' cut into the side of it so you can access the collets through it, and also prevents the collets being dropped into the engine ...

If anyone can reply who knows how to insert photos I took a few pictures as I went so I could put these up if anyone is interested - this also took place on a 2v engine but its exactly the same as any 170-250. If its too hard to insert a picture send me your email address and I can email photos direct...

 

[MrMootsie]

please post pictures! This is something I need to do as well.


TIA,
MrM

 

[MiniCJJ64]

When I got my head rebuilt the people forgot to put those seals in for me. A year later I found out that they didn't. So in auto class I bought all the seals and I only had a hour left in class and in 45 min I put them all in. I used the compressed air in the cylinders. After all that my engine ran great.

 

[Anonymous]

OK guys got a couple of photo's at:

http://johnnyscarstuff.blogspot.com/

Basically, the procedure is:

Remove fuel lines etc necessary to get to valve cover (rocker cover , tappet cover, whatever you call it in your end of the world...)

Take off the valve cover.

Undo the pedestal bolts that are holding the rocker gear down, remove carefully and place somewhere clean, dry and out of the way.

Remove all 6 sparkplugs.

Starting with number 1 cylinder, wind the piston about halfway down by turning the crank pulley (with the plugs out you can do this by hand)

Feed in your nylon clothesline rope (lots and lots of it!!) until you can't physically push any more rope in, then wind up the piston as much as possible - you can test that you've really snagged the rope by trying to pull the rope out the plug hole again - if you can't budge it , its tight enough - if you can move it, wind the piston down a little and try to get more rope in there....


Once you are happy that the rope is well and truly compressed, you can compress the valvespring and remove the collets. Before you do, get a lump of copper or some other soft metal and give the spring retainer a sharp tap - this will help dislodge tight collets (retainers) - then, compress the spring - using my handy dandy compressor or one of your own invention, push the retainer down, use something sharp like a scribe to dislodge the collets, and have a magnet handy to catch the collets - you can then uncompress the springs, lift off your retainer and spring, and then you'll see the actual seal - removing it is a bit of an anticlimax - just slide it off! Slide on the new one - I put a drop of fresh engine oil on the seal to help things , and when u push it on, sorta jiggle it from side to side slightly to help ease the lip of the seal over the end of the stem and slide it on. You can then reassemble , spring on, retainer on, re-compress and refit your collets - let the pressure off the spring slowly to make sure it seats properly, then finally give the end of the valve stem a tap with the copper to make sure its seated.

You've only got 11 more to do!!! This took me about 8 hours one Saturday but I've not looked back - no smoke, no oil consumption, lotsa power and smoothness!!

As for the valve spring compressor, it looks complex but it isn't - half of it is one of those clamps that you use on a bit of water pipe to clamp doors or whatever, the rest is cobbled up out of old bits of steel and pipe - if you want, I can take better pictures of it....

 

[JackFish]

get a lump of copper or some other soft metal and give the spring retainer a sharp tap - this will help dislodge tight collets (retainers)

A tap on the top with an appropriately-sized socket works nicely.

 

[Anonymous]

Yes, but the point of the softer metal is this - the retainers and valves are hardened - if you go hitting them with steel you run the risk of chipping or cracking them....

 

[6bangerwanab]

When I got my head rebuilt the people forgot to put those seals in for me. A year later I found out that they didn't. So in auto class I bought all the seals and I only had a hour left in class and in 45 min I put them all in. I used the compressed air in the cylinders. After all that my engine ran great.

off topic, but funny- my dads gmc safari smokes some, but mostly if he lets it idle. i did him a favor and looked up the tsb's (technical service bullitiins) and found out that in the early mid 90's GM kinda "forgot" to put valve seals in alot of reman engines! go figure!

on a more serious note, on most heads i prefer the lever type compressor, less likely to slip. but i guess that i have never really used one on a head that hasn't had studs.

 

[mugsy]

[/quote]Quote:
get a lump of copper or some other soft metal and give the spring retainer a sharp tap - this will help dislodge tight collets (retainers)

A tap on the top with an appropriately-sized socket works nicely.

I used the handle of a very large Craftsman screwdriver; the plastic is softer than the metal. Then a magnet to get hold of the locks.

I used compressed air to hold up the valves. I took the hose off of my compression check gauge, screwed on a few fittings and then hooked it up to the air hose with a quick disconnect.

As for pushing the valve down with your finger , if the valve is 1.5 inch in diameter, and you use 60 psig of air to hold up the valve, it would take 106 pounds of force to move the valve . In short, it ain't gunna happen!

 

[Anonymous]

True what you say about air pressure, but there's something that appeals to my cheapass way of doing things in a $2 roll of nylon rope! I reckon if you had to do these for a living then air is definitely the way to go, but for a one-off situation, particularly if you don't already have a compressor, its nice to know that the rope way is a valid alternative.....

 

[mugsy]

I know what you mean by not having a compressor. I was inthe hobby for close to 15 years before I got mine. But if one is handy (I used the compressed air at a glass plant where I was working) then its the way to go.

tanx,
Mugsy 8)