Valve Seals!

[cngodfather]

Hi! Just wondering what your thoughts are on valve seals. Here is an image of the cheap aluminum heads I bought. I want to buy something good for the valve seals. I would like to know what is the best route to take with what I have.

You must be registered for see images attach

 

[885speed]

I'd like to see what others have to say about this as well. Getting ready to pull the 305 out of my Camaro for full engine gasket replacement, and through the research I've done it seems like viton seals are the best you can buy.

 

[cngodfather]

My knowledge on seals are pretty much non existent. I was surprised to see almost nothing on the stock exhaust. It looked like a piece of plastic. On the intake, it looked like a decent deal. For a good performance engine, What are you guys using for both?

 

[evilunclegrimace]

My knowledge on seals are pretty much non existent. I was surprised to see almost nothing on the stock exhaust. It looked like a piece of plastic. On the intake, it looked like a decent deal. For a good performance engine, What are you guys using for both?

The seals on SBC engines are of three different kinds, There is a small square cut seal at the top if the valves that helps to limit the amount of oil that runs down the valve stem on all of the valves. There is an umbrella seal on the exhaust valves to keep too much splash oil from running down the valve stems and past the guides and into the combustion chamber ( it needs some oil due to the fact that the exhaust valve gets hot from exhaust gases)and there is a Perfect circle type seal that is pressed on to the intake valve guide to prevent oil from getting sucked into the combustion chamber due to the vacuum caused by the intake stroke of the piston. These seals do not stop oil from getting on /in to the valve guides, they just limit the amount of oil that is allowed on each type of valve.

 

[Redneckgeriatric]

positive seals are best, they press on to the guide, which may need machining for fit. there are cutters available that are inexpensive and easy to use. but if you are having a machinist set up the heads for your needs, he will cut the guides while he is at it. i think this is what mr grimace called perfect circle seals.
your guides apear to have the guides that accept the positive seals. whoever sets up the springs and or cuts the guides and spring seats will comfirm.

 

[evilunclegrimace]

https://www.coastalcasting.com/inventory/perfect-circle/

 

[evilunclegrimace]

https://www.bing.com/aclk?ld=e3l7JT...=4f72655810ec1354f6663b17eb067ff8&adlt=strict

 

[cngodfather]

This is all good information. I am still a little unsure about the o-ring seal. From what I understand, it is to be installed after the spring is compressed. Does it stay in the retainer? Or is it below the retainer? Is it really that important?

 

[evilunclegrimace]

This is all good information. I am still a little unsure about the o-ring seal. From what I understand, it is to be installed after the spring is compressed. Does it stay in the retainer? Or is it below the retainer? Is it really that important?

The seal is installed just below the valve keepers and yes it is important

 

[cngodfather]

Thank you. I am having a difficult time with figuring this out. This o-ring if put just below the keepers, appears to just sit on the shaft of the valve and it floats up and down? The o-ring looks like it will not sit in any stationary or sit firmly in any moving part. It looks like it is just there. I have single groove valves. o-rings in my kit can slip past the retainer. I swear it looks like they will just move from the seal to the locks at any given time.