The Stovebolt Site Forums The Shop Area Engine Shop valve stem boot

Does anyone know where to buy these valve stem boots that sit on top of the guide?

http://thumbs3.ebaystatic.com/d/l225/m/mzJkr8gRN0y2TLT-2aGgFeA.jpg


I tried Napa and chevsof40s, but both do not seem to have the part.

Thanks,

Judson

Judson,

Jim Carter sells a set that contains both styles of seals.

I just took a valve to Napa and told the inexperienced counter jockey to go find me some that fit. I thought that he would never leave the security of the all-knowing computer to go scrounging for me, but he eventually did. I dearly miss the 'old' Napa stores where they employed people who knew more than i do. Now they are all to eager to tell you that "they don't carry that part", just to make you leave.
Carl

I believe that Ford V-8's used the umbrella seal, late 60's and up.

Just go to any engine rebuilding shop and they will have them or they can get them.

I believe they come with a valve grind gasket set, at least mine always have.

I understand from previous discussions that they don't actually sit on the guide but move with the valve. Is this correct? Also, do you only put them on the intakes?

Yes, they are only on the intakes.

Thanks, Tim.

Been round these engines for many many years and it never has
made any sense to me why anyone would want to starve a valve
stem for lubrication. Metal to metal without lubrication
wears very nicely.
DG

I agree, Denny

What purpose did/does the original "seal" serve?

I was reading in the manual that these boots came stock on this years 216. It sounds like when they are missing, oil slips through and end up getting burned. Perhaps it was just that old design, or perhaps since the cap rests on the top of the valve, the oil which is needed for lubrication can stay in the valve stem shaft.

Judson,

What year manual shows those umbrella-boots rather than the ring "seals"?

They are the oil seal, just intended to keep engine vacuum from sucking oil past the valve stem into the engine. Also used on the big blocks. There is a lot of oil flying around under the valve covers during operation.

The O-ring is supposed to be for oil control, I've never
understood how it could control very much oil being at the top
of the valve and buried in the retainer. The umbrella
seal is simply a deflector and the positive seals such
as the Perfect-Circle seals improperly installed, can do a
little to much controlling and can wipe the stem
of all it's lubrication. Positive seals in the newer engines are
carefully designed to leave a thin film on the stem, not wiping
it dry.
It seems to me that the Stovebolts didn't come with any other
oil control than the O-ring because there just wasn't a whole
heck of a lot of problem with oil pooling around the guide.

Back in the early 60's the machinists in the back room at the
auto parts store that I worked at, knurled a lot of the worn
cast in guides. To control the oil on a lot of the V8's
especially because of the angled head and higher rpm, oil
pooling was a problem, so they usually installed the Perfect-
Circle seals.
Get Jerry in here, he's the expert in this department, I'm sure
he's been thru this discussion a thousand times.

Denny G

Thanks, Denny

I am interested in knowing how/when/where that original seal provided a seal on a 216/235/261. Maybe Dave, Jerry, or others will explain relative to those engines?

I'll be interested to hear what Jerry says also. I've always used the O rings and tested them by sucking on the top of the spring retainer. I always figured there should be some oil on the valve stem...the guide certainly isn't self-lubricating and the clearance between the stem and guide is small.
Jon

It's not a pool of oil to worry about...it's oil flying everywhere when the engine runs. Install a clear plastic valve cover and observe!

The engines with boots did not have an O-ring.

Knurling the guides was a way to save worn guides by changing the diameter.

My old 71 Chilton's shows them both; O-rings on some sixes and SV8, and "boots" on large V-8s.

The top of the valve guide can be machined to use the newer style seals.

Tim,
I am reading from the 41 Chevrolet Special Deluxe manual.
Judson

Hi Woodswarrior,

I appreciate how you guys are discetting this thing with the boot. Its interesting, especially given the poor oil system that this car has (as Ive heard). What I mean to say is that while I do not know as much as you guys know, when I took off the oil pan you can see how the oil flows down through the oil tubes in the pan and then is squirted out to hit a dipper on the lower part of the piston bearings. I guess that is not very effective...but it is what it has so Im running with it. My oil holes lined up well, just a little clogged with grime over all those years.

I did want to mention, however, that my valves also have an oil seal on the valve. So, there is the boot that rides on top of the valve guide, but there is also an additional rubber seal-or washer-that sits inside of the first groove at the top of the valve. The second groove is obviously for the spring clip.

It is funny, however, that the boot would try to keep oil in the valve, especially when the rocker arm is right above it and oil just flows freely out of that into the same space. I guess like one post mentioned, the boot is perhaps more for compression.

I appreciate your guys discussion because I am learning as I go through this and its good to understand how it all works.

Judson