Valve stem seals 67 L-36

[Lawrence S.]

Can someone suggest what seals to use for my application? My engine/heads are stock. Not sure if my valves use umbrella and "o"rings.

Thanks

Lawrence

[Joe L.]

Re: Valve stem seals 67 L-36

Can someone suggest what seals to use for my application? My engine/heads are stock. Not sure if my valves use umbrella and "o"rings.

Thanks

Lawrence

Lawrence------


ALL big blocks used umbrella-style valve seals. Only small blocks used the o-ring seals.

Assuming your valve springs are stock original (i.e. single spring with damper), you require a conventional umbrella seal last available from GM under GM #460527 but now discontinued. No problem, though; use Fel-Pro #SS71152.

If your valve springs have been replaced with the upgraded GM replacements (i.e. dual spring), then you require valve seals that are integral with the valve cap (retainer). I believe these are available under Fel-Pro #SS72513. However, I'm not 100% certain these will work.

It's also possible that your valve springs have been replaced at some earlier time and aftermarket springs were used. In that case, it's also possible that your valve guides were machined for positive-type valve seals. In that case you'll need to use positive seals compatible with whatever valve guide OD you have.

So, it really all depends upon what you find when you get in there. But, you KNOW it won't be o-ring seals.

One more thing: if you find that you have original valve springs (single spring with damper) and conventional umbrella seals, you'll be fortunate that you haven't broken one or more valve springs. These early valve springs are highly susceptible to breakage. In that case, your best bet is to replace all the valve springs. Unfortunately, the upgraded GM replacements, also used in PRODUCTION for 1970-74, are no longer available and I know of no aftermarket that are equivalent.

[Domenic T.]

Re: Valve stem seals 67 L-36

I use the stock O-Ring with umbrella. Reason is that it let's oil reach the valve stem and guide. You will use about 1 quart of oil every 1000 miles. That's a drawback to many but keeps the rings and valves lubed and the engine lasts longer. You can get a puff of oil on start up also which is not bad and is caused by the oil that drains down the valve guides when the engine sits, about a drop in each cylinder. That's what causes the 1 quart per 1000 miles.
With the O-ring type seal you need good oil and the engine can't be pampered because the intake valve will get a oil build up of burnt oil on the tulip part just under the guide travel and the valve will get heavy and the air flow will not be
as good. That can all be avoided with good oil and back to the 2K oil changes. I changed oil every 1000 miles and filter every other time. ALL my small blocks have the O-ring seals with umbrellas.
The major drawback of the new seals is that it wipes the oil off the valve stem and the valve stems and guides wear out much faster. In the 70's we machined the guide bosses to fit the positive seals that attached to the guides when the puff of oil was not acceptable at start. What happened then is that the engine guides and valve stems wore so fast and bad that a valve job was needed before it's time and the heads needed major work. The guides were worn, valve stems worn, valve seats were needed because of the worn guide and valve stem. Also the engine started burning oil because the bad guides and stems rocked so much that it wore the seal and now there was nothing to stop the oil from going down the valve stems and into the cylinders, especially the intake on the intake suction stroke.
With the O- ring seals a valve job was just that... Grind the valves and seats and put new O-rings on the Stems. The only wear was from lack of oil changes when using the O-ring seals.
Visible oil at engine start up was a big thing when I worked at the dealership. It was embarrassing to new car owners and Chevrolet changed the valve seals and did away with chrome rings. All that for bragging rights. Now you could say that you went to your oil change without adding oil!!
I would keep the heads stock and buy the extra quart of oil needed at 1000 miles. If you remember, the gas station attendant would ask you if you wanted your oil checked!

DOM

[Joe L.]

Re: Valve stem seals 67 L-36

I use the stock O-Ring with umbrella. Reason is that it let's oil reach the valve stem and guide. You will use about 1 quart of oil every 1000 miles. That's a drawback to many but keeps the rings and valves lubed and the engine lasts longer. You can get a puff of oil on start up also which is not bad and is caused by the oil that drains down the valve guides when the engine sits, about a drop in each cylinder. That's what causes the 1 quart per 1000 miles.
With the O-ring type seal you need good oil and the engine can't be pampered because the intake valve will get a oil build up of burnt oil on the tulip part just under the guide travel and the valve will get heavy and the air flow will not be
as good. That can all be avoided with good oil and back to the 2K oil changes. I changed oil every 1000 miles and filter every other time. ALL my small blocks have the O-ring seals with umbrellas.
The major drawback of the new seals is that it wipes the oil off the valve stem and the valve stems and guides wear out much faster. In the 70's we machined the guide bosses to fit the positive seals that attached to the guides when the puff of oil was not acceptable at start. What happened then is that the engine guides and valve stems wore so fast and bad that a valve job was needed before it's time and the heads needed major work. The guides were worn, valve stems worn, valve seats were needed because of the worn guide and valve stem. Also the engine started burning oil because the bad guides and stems rocked so much that it wore the seal and now there was nothing to stop the oil from going down the valve stems and into the cylinders, especially the intake on the intake suction stroke.
With the O- ring seals a valve job was just that... Grind the valves and seats and put new O-rings on the Stems. The only wear was from lack of oil changes when using the O-ring seals.
Visible oil at engine start up was a big thing when I worked at the dealership. It was embarrassing to new car owners and Chevrolet changed the valve seals and did away with chrome rings. All that for bragging rights. Now you could say that you went to your oil change without adding oil!!
I would keep the heads stock and buy the extra quart of oil needed at 1000 miles. If you remember, the gas station attendant would ask you if you wanted your oil checked!

DOM

DOM-------


O-ring seals cannot be used with a big block (like the L-36 in this case). Mark IV big blocks were never designed for the use of o-ring seals.

[Domenic T.]

Re: Valve stem seals 67 L-36

Joe,
My mistake, I was talking SB. I need to find a list of L options somewhere!!!

Dom

[Lawrence S.]

Re: Valve stem seals 67 L-36

Thanks guys. I am going to take a picture of the valve springs tomorrow and post it so ya'll can tell me what type of springs I have.