Valve stem seal question
 

So after reading thread after thread I think I have an understanding of what I need but I want to make sure. So I have a set of 4x heads. The valves have been replaced with ferra valves without the o-ring grove. So since the original o-ring seals are out is there a valve seal that I can install that will not require having to machine the heads for the positive seals like the umbrella style? If not and I do have to machine the seals has anyone had any luck with the DIY tools the sell for this?

I would go for cutting the guides now, as this will allow you to run smaller OD seals which many times is a need when you step up to stronger / better springs that are needed for higher performance Cam's

The dIY / cutters that you can buy work great, but if there is a shop local that can do it for you by the time you buy the cutter and pay for the shipping the price will be about the same.
Of course if you see yourself having need of the cutter again down the road , or have a buddy that will need the same work done then you can split the purchase cost.

+2, cut them for the good seals. My cutter is .530" nearly as I can remember (haven't used it recently). The good seals have a metal shell with the seal/spring that wipes the valve bonded to them, light years ahead of any type of factory "O" ring or umbrella seal......Cliff

Have a shop cut the guide bosses down for you and use a Viton seal. It's standard fare on all my factory head builds.

ok, so I will be cutting the bosses for seals. After my experience with the machine shop that did my block and heads I will do this myself, I was truly unhappy with the work done but I guess that's what happens when you don't do the work yourself. So does anyone have a part # for the Viton seals or know of a good place/site to by them? Are they something my local parts store can order?

It will depend on which size you cut the boss down to, but Comp Cams, Manley and a few others offer an 11/32" x .530" seal that I use a lot.

I would grab a valve, the retainer you're going to use, and the locks you're going to use, and use that in conjunction with how far the boss is cut down. You want adequate retainer to valve seal clearance.

+2

If using factory Pontiac retainers they are pretty long to seal off the "O" rings so reduce seal clearance some.

If I'm using factory retainers and a bit too close for comfort, you can remove some of the material from the bottoms of them below where the keeps sit, it will not reduce their strength in any way......Cliff

The seal for 11/32" x .530 is VS-529. The VS-530 will work also, but the 529 fits the giude better. VS-530's fit too loose on some guides cut to .530 as some cutters don't cut them exactly to .530". I use the VS-529 and all these applications. I don't even use the VS-530 anymore as some have just pulled right off the guide.

Before you cut the guides down, install the valve, and retainer, with keepers, and measure the distance between the guide, and retainer. Then, when you cut the guide down, be sure to cut it .200" deeper for the seal, and add at least another .050" for seal to retainer clearance at full lift.

So, if you measure .500" between the guide and retainer, and you are running a cam with, lets say .525 lift, then you need to cut the guide down at least this much:

.525" lift, + .050" clearance, + .200" for seal = .775" clearance between retainer, and guide, after cutting it down.

Definitely buy the .530" cutter, as it leaves the guide thicker at top, and less likely to crack or break later on. Plus, .530" seals are usually easier to come by. I stock much more of them than I do the .500" seals. I reserve the .500", and .480" seals for triple springs where you need a small OD body on the seal to clear the inner spring.

Also be sure to set the head up so that the spring pad is level so that your pressure on the drill powering the cutter is verticle , as you do not want to apply side pressure which can make the cutters pilot beat up brand new guides.
If you have or can use a drill press you will be a leg up on doing it well.
Also be sure to lube the guide I'd well!

My .530" cutter actually sizes them for a pretty decent interference fit so you've got to have the correct driver to seat them or it will damage the top of the metal shell and distort the seals. I wouldn't just grab a socket that fits over them to drive them in place, take the time to make a tool to support them while being driven in or buy the correct tool.....FWIW.....Cliff

thanks for the info guys. I will be cutting the bosses myself. So it I will need to pick up a cutter and after looking into seals it seams that .530" is definitely the way to go. Anyone have a cutting tool they would be willing to part with?

There are many different seals in the .530" size you will be machining to. One I like allot that allows decent stem oiling and seals well and fits the guide well is available from Summit racing and others. They are marketed by Comp Cams as part number 518-16. $17.97 a set. They are made by US seal in MI and repackaged by many manufacturers. You can buy direct from them with a $25.00 minimum order. Depends on how many you want.

I'm sure you mean when assembling the heads, and NOT when cutting the guides down. Lube in the guide while cutting the guides for seals is a bad idea as it allows fine cast iron filings to get stuck in the lube, and really scratch/chew up the guides. The pilots fit the guide loosely, so no need to lube them for this operation.