[4dblnkldude]

I'm gonna put some valve seals in my little 70 Firebird. I've never did this in the car on as assembled engine before. I assembled a set of 6x heads a year back, basically stock, I just put the Fel pro seals on and the Fel pro little o ring on the valves. the engine runs awesome, I broke it in January. Anyway, an old friend stopped by the other day and said I may have to cut them. Cut them with a cutter? A valve seal cutter? I have not been able to get a hold of him the last couple weeks for him to elaborate. This guy has built hundreds of engine and been a hot rodder since the late 60's. So what's the deal do I got to cut them? I didn't on the 6x heads. I haven't dug up much on it.

[Goatracer1]

What I think he means is you may have to cut the top of the valve guides. For Perfect Circle type of seals the top of the valve guide has to be machined for them to fit. Some of the Pontiac heads had the intake valve guide cut from the factory for them. You don't usually need them on exhaust valves. It has nothing to do with the little O-ring seals.

[steve25]

The stock valve seals on any regular production Pontiac V8 are just the O rings like you used on your assembly of the 6X heads.

To change them in the car you need bring the piston up to TDC, stuff nylon rope into the chamber to support the valve as you remove the spring.

KD tools makes a bar lever type tool for removing the spring in the car.

This tool works fine but can chew up the threads on the rocker studs so I make a protection sleeve out of a Aluminum soda can .

Sometimes you need to smack the retainer with a socket to fee it up from the keepers.

With the O rings you must run the stock retainers and the oil splash shield, non stock retainers or no splash shield will require positive type guide located valve seals to be used which can only be done by machining the head off the car.

[fairwayhit]

I use the proform 66784 valve springs compressor.
I would highly recommend it or one like it. It was a little tricky to use around the brake booster but I was able to take the pivot pin out, screw it in and then put the pin back in.

It locks in place and holds the spring down so you can get the little retainers out. You definitely don’t want your drop one of those.


In the past I’ve tried different valve spring compressors and a lot of them are very difficult to use (especially when heads are on the car).

Not trying to sell you anything. I just wanted to pass on my experience with this particular
type of tool.


Sent from my iPhone using Tapatalk

[Shiny]

Originally Posted by fairwayhit

I use the proform 66784 valve springs compressor. .....

Thanks for this. It looks like a great tool with the "cam-over" lock.

Is there any issue using it with the splash shields?

[fairwayhit]

No problem with splash shields.


Sent from my iPhone using Tapatalk

[4dblnkldude]

OK so they do not have the rubber seals at the valve guide? How do you cut them on the car? Can you even do that? I got a couple different spring compressors.

[rolling money pits]

Are you having an issue with oil smoke/consumption?

You say you used the o-rings when putting heads together…..are they still there?

You cannot cut the valve guides for positive valve seals when the heads are on the car, they must be removed and sent to machine shop.

Positive valve seals eliminate factory o-ring style that are on stem by the keepers, they slide over the protruding part of the valve guide.

[4dblnkldude]

Originally Posted by rolling money pits

Are you having an issue with oil smoke/consumption?

You say you used the o-rings when putting heads together…..are they still there?

You cannot cut the valve guides for positive valve seals when the heads are on the car, they must be removed and sent to machine shop.

Positive valve seals eliminate factory o-ring style that are on stem by the keepers, they slide over the protruding part of the valve guide.

It was a different set of heads I previously assembled. The ones on the car are 17's. And yes I am having an issue with smoke and oil consumption. So I guess the o rings seals are just rotted out. The car did sit for 25 years. So I'm assuming its just the o rings not the seal thats on top of the guide?

[steve25]

There is no seal on top of the guide if the heads are stock, and yes if the O rings are dried out I have seen them turn to rubber dust or crack and split into little pieces and the motor will smoke and use oil pretty bad.

[4dblnkldude]

Damn, I'm learning! Thanks so much! Of all the things I've done. What got me thinking was another old friend gave me a set of 96's and 13's a year ago. I looked at them them and thought they were stock. I guess they machined for the positive seals. The 6x that I just assembled were fresh from the machine shop so I guess my guy cut them.

[unruhjonny]

instead of nylon rope (unless my memory is failing me) there is this neat adapter you can use to put compressed air in the cylinder to hold the valve up.

I have never done it myself (I've only changed seals on loose heads), but think it's a super neat idea.

[steve25]

Ok I now am lost here !

What heads do you have on the car that are the issue?

How have you determined that you have valve guides that are cut for seals, yet do not have them?

Here’s two photos.
One has the stock factory long bottom retainer that is needed to just run O rings .
The other photo is a aftermarket ( short bottom ) retainer which does not allow a O ring seal to be used.

Both of my photos show a positive type common valve seal being used the does not require a O ring seal to be used with it.
Sometimes this type of seal is Teflon and is white .

[steve25]

Johnny on my last motor I did springs on in car I had to use rope.
The motor had thin rings and a non rope rear seal, so with air in one cylinder it would just spin over very slowly.
When I lowered the air pressure to stop that there was not enough to hold the valve closed when busting the retainer free.

[Holeshot71]

Originally Posted by steve25

Johnny on my last motor I did springs on in car I had to use rope.
The motor had thin rings and a non rope rear seal, so with air in one cylinder it would just spin over very slowly.
When I lowered the air pressure to stop that there was not enough to hold the valve closed when busting the retainer free.

Usually when you put air in the cylinder the piston will stop moving when it gets to the bottom. Not sure what thin rings and rear seals have to do with this?

[steve25]

Simple, I would rather not chance a valve dropping, so I prefer to spend 2 minutes more per cylinder stuffing rope in.

[4dblnkldude]

I have not took the covers off yet so I have no idea what seals they have. It is a stock 70 firebird 350 with 17 heads. The engine has never been apart. I like the rope idea.

[unruhjonny]

um…
if it’s a 1970 engine, and it has 17 heads, then it HAS been apart;
The 1970 350 heads were #11.

[4dblnkldude]

[QUOTE=unruhjonny;6503922]um…
if it’s a 1970 engine, and it has 17 heads, then it HAS been apart;
The 1970 350 heads were #11.[

They are 11's! Sorry