bj1k

Looking for opinions from the engine gearheads on the preferred valve seals to use on the chevy small block. They offer the standard o-ring seals that came from the factory and they also offer the umbrella seals. I have used both at some point or another either by themselves or installing the o-ring seals along with the umbrella seals on an older engine that had a little more wear. I just bought a period correct engine for my 72 Corvette with only less than 50k. original miles but it was taken out of the original car over ten years ago and been sitting in storage so I'm freshening it up with new standard bore rings and all new seals and gaskets . At this point I'm trying to decide if I am going to just replace the valve seals with the stock o-ring seals or just the umbrella seals and leave the o-ring seals out. Or use both. What do you think ? Opinions welcome.

Nowhere Man

umbrella seals

gjohnson

I used both when I did mine.

sandy laker

I'd install a set of Viton umbrella valve stem seals along with a new set of Z28 valve springs. Your engine will thank you.

DUB

Honestly...knowing that your engine is a stock configuration. As the previous replies have shown...there are different opinions.

I generally put the 'o' rings back in as designed. and if allowed...I will put the plastic umbrella on it also. https://www.goodson.com/images/P/8563781.jpg

I do not beat these down onto the valve guide area. But that is just me.
http://thumbs.ebaystatic.com/images/...E~G/s-l225.jpg

But in most cases...due to the engines I work on have so many miles on them. The 'o' rings work and last for a long time because with the cylinder heads still being on the engine...there is no way of detecting on the amount of valve guide wear. ( Sorry...I am not an engine builder with the ability to know how it 'feels'.)

I do know...which more than likely does not apply in this scenario (due to valve lift and valve spring design)....that if using a different design of seal that is not made to lock onto the valve stem correctly...this type of seal can cause for problems when the valve spring is compressing and allowing the keepers to come out.

DUB

bj1k

I agree with you DUB. When I use both the stock o-ring seals and the umbrella type I leave the umbrella's at the top of the stems right under the keepers instead of driving them down over the valve guides as they were designed to do. Just a little more assurance . I'm just trying to decide whether I need both type of seals on a low miles engine or if it is overkill . I'll probably just throw them both on.

Rescue Rogers

My experiences lately for things in general, if you're thinking of doing it, its best to do it. When I didnt follow that little tickle of intuition its bitten me in the ***. Just my 2 cents

Easy Mike

Me too.

gjohnson

Non locking umbrellas are made to position themselves up over the valve guides,like an umbrella.When you install them they go over the guide. When the valve opens then closes for the first time it stays in the position on the stem that it slid to which is above the guide.

bj1k

Some of the early design umbrella seals had metal rings around them to hold them down on the valve guides . I don't see those much anymore. Most are just rubber with no metal attached which adjust themselves like you described.