Valve stem seals

[TIB3300]

Stem seal help


I have a complete gasket set from rock autos, but the Valve stem seals don't seem to fit Ive only got 8 of one type and 16 of the other in the kit
Can anyone advice me on them ?

I have the same as the ones shownbelow . but there seems to be differant types like the 2nd set show

IMG_20191227_153827164.jpg (31.78 KiB) Viewed 700 times

Why are they different? and what and when did they change if at all ?

https://www.ebay.co.uk/i/303005963629?chn=ps






Thanks

[Pete]

I think the 8 off ones normally need the valve guide machined to suit them. Much better oil control though....

[Blue]

Some later small block heads have rotators under the springs on the exhaust valves, I think the 8 are probably for those at a guess.

[TIB3300]

Thanks

Done a bit of research and they seem to be an umbrella seal dont look the best idea

https://www.forabodiesonly.com/mopar/th ... ded.19040/

[Dave999]

mine had plastic based umbrellas on all but thy take more space and hit the guide top with some guide and valve combos, when you put in a high lift cam.

the positive seal type are better, modern and lower profile. the plastic ones heat harden and fall off and end up in the sump eventually

i'd put the positive seal type on the inlets. they are the ones where there is vacuum at the guide as they open. too much oil can be sucked in, you need some but not enough to cause smoke

I initially ran nothing on the exhaust. but swapped to the positive seal type later...although with hindsight probably no need. little or no vacuum, the guide is kinda splash lubricated, anything sucked in gets blown out the exhaust if it doesn't get toasted first on the exposed sections of the valve

felpro do a metal bodied push fit positive seal type, that fits a bigger guide than most

Dave

[Dave999]

for a standard build 16x plastic umbrellas fine if they are all like the picture they work ok
they fit tight on the stem and just avoid oil off the rocker flowing onto the interface between valve and guide.

put in 8 or 16 of the other type for high lift cam, non standard initialled height retainer/valve stem length. buy a set of 16 and if you get the guides done get some put in with an OD that works with the stem seals or get big fat ones put in and machined to fit.... 1 extra process per guide

worth getting oem sized seals, cheaper in the long run and available from stock at Mopar or rockauto. but only if you use the 3/8 stem valve
if you go for the thin stem valves 11/32 normally used in modern or aluminium replacement heads bit more research to find an OEM stem seal
thin stem valves more space in the port...less restriction etc.....

you don't need anything too funky here...

[TIB3300]

Cheers Mr

Went with some new funky silicone ones , they do both in and out