seal, valve stem - urgent help needed !

[Lorenzo]

I have posted the below message into the another subject ( Huge engine oil consumption), but because I need urgent suggestions I post it again into a new subject.

....... now I have the car at a local workshop, and after having dismounted the engine head they saw it full of oil, due to the fact that a previous owner made some works on the head, installing seal valve not properly, so that the seals were out and someway,moving togheter with the valve movement, "pump" the oil into the combustion chamber.

It's so difficult to adapt the head for new seal valve sterm into my engine head ? An italian jaguar spare parts supplier is telling me that my engine head wasn't designed to use seal valve sterm, and that Jaguar solved this problem on a next version of the engine: is it true ? Do you have any suggestion about if and/or how about the installation of new goetze rhiag seals valve stem on all inlet and exhaust valves ?

[Dave K]

Lorenzo,

My engine is a 3.8 that was originally destined for the XK150S I had my head overhauled back in 2003 to include valve stem seals. It's an easy job for a machining company to do. You would have to strip your head and let them fit the later valve guides with the recesses in the them to accept the seal. Since your car is a 4.2 I am surprised it hasn't already got them, I'm sure they were fitted to the late 3.8's and all 4.2's. As far as I can remember the stem seals are only fitted on the inlet side and not the exhaust or is it the other way round?

Dave

[christopher storey]

Seals are only ever fitted to the inlet valves, for two reasons

1. Temperatures on the exhaust side are much higher and would demand rather special seal material

2. More to the point, there is very little suction on the exhaust valves, it only occurring to a very small degree during the last part of the overlap period

[Dave K]

Thanks Christopher, not feeling 100% today and couldn't remember. Am I also right in thinking the later 4.2 engines had the stem seals fitted as standard?

Dave

[PeterCrespin]

Modern Viton seals can be fitted to all valves but exhausts don't mind a bit of oil. Only the Series 3 XJ big valve heads had seals I think 1979 onwards. Might be a few before then. Jaguar later guides inlet and seals MUST be used only with the later shallower retaining collar and tappets or they will hit the seal and pump oil down as stated. Using no seals at all should not be acproblem if everything is in good condition.

Pete

[PeterCrespin]

Shallower collars and collets, sorry, not tappets. It's 11.15 pm here in Dallas at the JCNA meeting and drinks have flowed... hic!^#*

[38E]

As Dave said, your engine ought to have been built to use the seals. So it should already have valve guides which incorporate a snap-ring groove to retain the seal. However, if the guides are worn, it's probably best to renew them at the same time as installing new seals anyway. Either silicon bronze or regular cast iron guides would be preferred. I retrofitted seals to my 3.8, using new silicon bronze guides and the later valve hardware to accommodate the seals (which you should already have). Here are some pics of my hardware, old and new. The new ones are on the left. Note the shorter collet and retainer and the relieved spring seat, all to allow room for the seal. This work, together with new piston rings completely cured the oil consumption and smoking on start-up

[Lorenzo]

Thanks to all, thanks Clive, I will follow your precious suggestions to solve the problem.

Lorenzo

[Nick]

Oil seals were only fitted to inlet valve guides from December 1966 onwards (from engine No. 7E11668, 7E52687). My March '65 car didn't have them.

Nick

[Skylink]

Hi Nick,

Do you know of a supplier of Viton e type valve stem oil seals in the UK?

Regards,
Walter

[MarekH]

If these are the same as for the v12, i.e. a 5/16" stem and 1/2" seat, then you can fit teflon seals if you want to, subject to their not being too tall such that they do not hit the retaining collets at full lift.

I have a few sets of v12 low profile teflon valve stem seals for people who need them for high lift cams. (Standard teflon seals are substantially taller than the oem rubber seals and thus have less clearance at full lift with a standard cam.)

kind regards
Marek

[Skylink]

Thanks MarekH,

How would I get those seals from you? I need them for the intake valves for a 1970 e type Roadster

Regards,
Walter.
Email: skylink@eircom.net