Valve Stem Oil Seals

topcatcustom · Post by **topcatcustom** » Sun Apr 19, 2009 8:11 am

Putting my heads together at last

but opened the bag of goodies I got in my gasket kit and apart from countless gaskets and big O rings etc I don't have a clue what are for (how many seals are there on a RV8?! I'm assuming most of them are for injection manifolds etc?) but there are 2 possible stem seals!
There are 16 of 2 different types- 1 set are O rings that are a good fairly tight fit on the valve stems, and the other are like pieces of tube/O rings with flat ends that are a pretty loose fit on the valve stems but about 4mm thick! I cant see that the loose ones will scrape any oil at all and are also so thick I would need to take even more off my guides! But the O rings will just sit on the valves underneath the spring retainers unless inertia keeps them down...
Want some help please as would like to put the heads back together and bolt them down!!!

Post by **katanaman** » Sun Apr 19, 2009 6:02 pm

what heads are these? Sorry you have probably said a few times but I cant remember. Early heads just have flat rubber washers that go over the valve stems (kinda like tap washers) and only on the inlet valves. Exhaust valves don't really need seals since there isn't any vacuum. So if its early heads look for 8 of these.

topcatcustom · Post by **topcatcustom** » Sun Apr 19, 2009 7:47 pm

Yes I got them all in a gasket kit but they may be a cheap useless set. I will get a set of 8 flat ones this week!

mgbv8 · Post by **mgbv8** » Mon Apr 20, 2009 7:00 pm

Tom
I think you will want the rubber washer type on your heads.

A couple of questions:
You are fitting a wilder cam arent you. Have you already trimmed the tops of the valve guides to allow for the extra lift? If not, JE charges around 40 notes to trim these down and to machine them so they will take the later and much better blue knock on seals.

If you have already trimmed the tops of the guides down, have you allowed an extra 2.5mm for the thickness of the rubber washers? If not you might find that they just get chopped off as soon as you run the engine mate.
This will leave you with a skinny rubber ring on the stem and a washer with a bigger hole flapping around on the stems until they fall apart and end up in the sump.

Perry

topcatcustom · Post by **topcatcustom** » Mon Apr 20, 2009 8:42 pm

Hi Perry, I took about 100thou off the guides, and found the right rubber washers in my gasket set! Only to find they dont fit within the inner spring, so trimmed half a mm off the edge and they went on fine. If I had known it only cost £40 I would have got them done for the later ones! Never mind, done now and heads built up this evening.

Was going to start a new post but you might be able to give me a quick answer- when I built my A series engine I put blue tack or something on the pistons, bolted the head on loosely and turned the engine over by hand and took the heads back off to see if there was any clearance issues with valves to pistons.

How are you supposed to check this on a RV8 when the lifters are hydraulic and will just take up half of the movement?! My heads are the mid ones (14 bolt, 1990 Range Rover) so not skimmed like the later ones, plus they have not been skimmed by me as were dead perfect.

TC

Post by **katanaman** » Mon Apr 20, 2009 10:32 pm

ah originally the P6 engines with double valve springs didnt have any stem seals.
To check the RV8 clearance you need either a dummy lifter (make one from an old hydraulic lifter and weld/pack it) or use a solid mechanical lifter. Drop me an email address in PM and I will send you a really good PDF by Crane on how to go about it.