Moparts

440 Valve Seal - Is this right?

Posted By: Plum440

440 Valve Seal - Is this right? - 03/16/19 07:32 PM

Having a problem with excessive blue smoke at startup (eventually goes away) and notice it again with a hard acceleration after off-gas cruising to a stop. Took valve cover off and noticed valve seals are “up” on the valve..see picture. Is this normal? Thanks Guys!

Attached picture 77998AB8-2F33-47CF-9B62-ABB4E122A705.jpeg
Posted By: Clanton

Re: 440 Valve Seal - Is this right? - 03/16/19 08:20 PM

I think after things get moving it stays down but there are better seals I think.How are the plugs?
Posted By: GODSCOUNTRY340

Re: 440 Valve Seal - Is this right? - 03/16/19 08:45 PM

Those umbrella seals move with the valves so that is normal. The valves need some lubrication or they would lock up. If you're getting a lot of smoke your guides are most likely getting worn beyond spec.
Posted By: Cab_Burge

Re: 440 Valve Seal - Is this right? - 03/16/19 09:32 PM

Originally Posted by GODSCOUNTRY340
Those umbrella seals move with the valves so that is normal. The valves need some lubrication or they would lock up. If you're getting a lot of smoke your guides are most likely getting worn beyond spec.
iagree
Pull one of the plugs and see if they are shiny or dull scope If shiny there is oil on them, if dull look some where else for the problem wrench
Posted By: Plum440

Re: 440 Valve Seal - Is this right? - 03/16/19 09:39 PM

Plugs are good. Tan and normal except for #8.
Posted By: Plum440

Re: 440 Valve Seal - Is this right? - 03/16/19 09:43 PM

Thanks all for the replies. I’ll keep digging....
Posted By: lewtot184

Re: 440 Valve Seal - Is this right? - 03/16/19 09:55 PM

try the big block chevy umbrella. they are a little longer than the mopar umbrella and I prefer them. also, it looks like your using the later b-engine "umbrellas"; they're too short.
Posted By: fast68plymouth

Re: 440 Valve Seal - Is this right? - 03/16/19 10:11 PM

Look to see if the intake valves have those same seals, or if they’re longer umbrellas, or the positive style seal.

The short umbrellas are for ex use only, and if the guide clearance is on the loose side, you’ll get some smoke on start up.
Posted By: buildanother

Re: 440 Valve Seal - Is this right? - 03/16/19 10:48 PM

Listen to "fast". The taller seals are indeed the intake seals. Them shortys I don't even like using on exhaust. But I worked on many many Gm's, buicks especially that had a shield inside of springs and some used NO exhaust stem seals.
Posted By: mopars4ever

Re: 440 Valve Seal - Is this right? - 03/16/19 11:55 PM

I once had a leak at the intake gasket that had similar issues as yours.
Posted By: GODSCOUNTRY340

Re: 440 Valve Seal - Is this right? - 03/17/19 01:51 PM

The exhaust valve seals are shorter because the exhaust valves need more lubrication than the intake valves. Exhaust valves get a lot hotter than intake valves and there is no vacuum pull on the exhaust like the intake. The vacuum pull on the intake helps pull some oil between the stem and guide to help lubricate, there is no vacuum pull on the exhaust side so Chrysler made the seal shorter to help get a little more oil to the exhaust valve guides so they don't seize. I wouldn't recommend using the tall seals on the exhaust valves or you'll get worn out guides and/or sticking valves, they need more oil than the intake valves.
Posted By: dvw

Re: 440 Valve Seal - Is this right? - 03/17/19 02:20 PM

By the looks of it the seal diameter may be to large for the spring. The seal shouldn't contact the inner portion of the spring.
Doug
Posted By: fast68plymouth

Re: 440 Valve Seal - Is this right? - 03/17/19 02:37 PM

I’m pretty sure up until early/mid-70’s that “from the factory” the BB heads had the long umbrella seals on both intake and exhaust.

Someone here probably knows more about that than I do.
Posted By: lewtot184

Re: 440 Valve Seal - Is this right? - 03/17/19 02:57 PM

Originally Posted by fast68plymouth
I’m pretty sure up until early/mid-70’s that “from the factory” the BB heads had the long umbrella seals on both intake and exhaust.

Someone here probably knows more about that than I do.
'452's had the short "umbrella" for the exhaust; if you want to call it an umbrella, and the "positive" push on for the intake. what I call the standard umbrella is noticeably longer than what's in the picture. the bb chevy is just about 1/8" longer than the standard mopar umbrella and I use them. looking at the picture I wonder if that's an aftermarket retainer? if so it may be clobbering the intake seals with a performance cam. I do see performance springs so there may be more to the story than the OP has stated.
Posted By: lewtot184

Re: 440 Valve Seal - Is this right? - 03/17/19 03:33 PM

i stepped out in the garage and got some seals out and did some measuring. if the head has an un-trimmed guide boss then there won't be a big difference between the chevy umbrella and the mopar due to the chamfer at the top of the boss. the mopar umbrella is molded to fit the chamfer. when the boss is trimmed a little; removing part or all the chamfer, the chevy umbrella will give more coverage because it is molded flat on the inside. I prefer the most coverage I can get. there's a few things to look at here and as aftermarket parts are used instead of factory more thought needs to be given to coverage. more exposure of the stem/guide will lead to more oil in the chambers when using umbrellas and I've actually had umbrellas work better than some of the so-called positive seals.
Posted By: Cab_Burge

Re: 440 Valve Seal - Is this right? - 03/17/19 04:40 PM

Originally Posted by fast68plymouth
I’m pretty sure up until early/mid-70’s that “from the factory” the BB heads had the long umbrella seals on both intake and exhaust.

Someone here probably knows more about that than I do.
iagree
I never saw two different length valve seals until the after market company like Fel Pro starting selling them shruggy
Posted By: jlatessa

Re: 440 Valve Seal - Is this right? - 03/17/19 04:42 PM

I haven't used umbrella seals for a while, but if I remember right, some suppliers included a plastic/
Cellophane type protector to put over the valve stem to keep the sharp edges of the lock grooves from
gouging the seal ID on installation.

Maybe a good amount of grease might serve the same purpose.

Just something to consider...Joe
Posted By: Dave Hall

Re: 440 Valve Seal - Is this right? - 03/17/19 05:35 PM

Poke the seal with a screwdriver and see if it's pliable. I replaced a bunch of them on cars that sat too long. Hard seals caused the start up smoke and the replacement seals did the trick to solve the issue.
Posted By: fast68plymouth

Re: 440 Valve Seal - Is this right? - 03/17/19 07:04 PM

The Mopar performance “viton” valve seal package came with 8 short and 8 long umbrellas(P4120492).

In the Fel-Pro catalog the long umbrellas are listed as the “early” style(SS12419).

Since the bottom of the seal is hidden by the spring/damper in the OP’s pic, it’s hard to say for sure which style seal it is, but I thought it seemed like it was the “short” style on that ex valve.

Attached picture C57E5BA9-1972-4B7F-9CFE-1FE654DD6928.jpeg
Posted By: lewtot184

Re: 440 Valve Seal - Is this right? - 03/17/19 11:01 PM

Originally Posted by fast68plymouth
The Mopar performance “viton” valve seal package came with 8 short and 8 long umbrellas(P4120492).

In the Fel-Pro catalog the long umbrellas are listed as the “early” style(SS12419).

Since the bottom of the seal is hidden by the spring/damper in the OP’s pic, it’s hard to say for sure which style seal it is, but I thought it seemed like it was the “short” style on that ex valve.
there's a third type of factory seal. it fits the '452 head intake boss. it's a push on neoprene and reminds you of a positive seal.
Posted By: fast68plymouth

Re: 440 Valve Seal - Is this right? - 03/17/19 11:23 PM

It is a positive seal........ as in it’s positively positioned on the guide boss.

As I recall, many of the later LA engines used then on both intake and exhaust.

They’re available in Viton material, which would hold up okay on the exhaust valve.
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