Which type of valve stem seals does the engine have?

[Elsa]

I'd love to know the answer to the subject before I take anything apart or off the engine unnecessarily...

Truck: 1971, 88", 2.25 petrol, IIA (24440729G / June 1970), with original engine #30700406A.

Seems there are two types of valve stem seals for 2.25 engines (please see attached pics):

1. O-ring that sits recessed down inside the valve guide tube wall (stem pushes up through it for the sealing factor). The O-rings are not visible when valve cover is off, since they're down inside the valve guide hole about 1/2". To replace them the head has to come off as I know it, and I won't be doing that job. In this case, I'd not take anything apart and just have my trusted shop do it.

2. An "Umbrella" type (as it's called) that simply slides over the already inserted and protruding valve stem and valve guide top. These rubber 'umbrellas' are visible with the valve cover removed, and based on numerous videos, they can be replaced with the head on, and just removing the valve cover. This I can do.

Question is... before I take anything apart (possibly unnecessarily if I have O-rings), how do I know which type of valve stem seals are on the engine? (ie: Is there a known change over date / engine number cut-off from one type of seal to the other?)

Thanks

[roverp480]

My parts book shows the change of seal happened on S2A engine suffix K onwards ( Chassis Suffix E onwards ) , but LR did a kit to change them as a retro kit, which I did on my S2A Land Rover . The easiest way to check would be, as said , to lift off the rocket cover as the later seals can just be seen through the valve spring coils . The change was advised in the LR Service Newsletter Volume 2 No. 30 dated March 1968. On that basis your 1971 vehicle if it has its original engine , would have the later seals . The Newsletter also advised the ignition timing pointer changed from the flywheel to be on the front cover and bottom pulley, so if you have that its likely to have the lip seals on the valves. The Land Rover Series 2 club has the service newsletter's on it web site , viewable to members. https://www.series2club.co.uk/public_pages/index.php

[Elsa]

@roverp480... you're an anomaly - what would we do without you?! Thank you kindly for the (always) perfectly detailed reply. I'll see if I can find the timing pointer. But overall, with your good news I may as well optimistically remove the valve cover and check the seals, since my engine is original/numbers matching. Strange though that my engine (A) is much earlier than the LR engine change at (K) but my chassis (G) is later than the LR seal change at chassis change (E). Maybe Solihull had an abundance of suffix A engines that made it into very late 2A's... but that seems odd. I attached a pic of my engine info, just for fun. Thank you again - will share what I discover beneath the valve cover...

[roverp480]

I must admit I had never come across a 307 series engine number before but I have just found that the 306 and 307 series of engines are unique to the 88" vehicles with engines to meet the US Federal emissions regulations . 307 series ( 8:1 compression ratio) were Suffix A . Just to confuse , 306 series of engines ( 7:1 compression) were suffix K. Again found on the LR S2 club web site. Its listed in parts supplement 606494 for US vehicles

[Elsa]

@roverp480, Yes, quite interesting. I too didn’t know the US had dedicated engine numbering. It’s in line with the extra emissions items mine has… fuel vapor evaporation tank below driver’s side, charcoal canister and pcv valve beneath the hood, along with one other red canister/filter? (pic attached, sorry host rotated them) in the heater hose line. So would such a ‘307’ 88” be considered a NADA model?

On the valve stem topic, I’m hoping if I’m able to replace them via valve cover removal that the blue exhaust smoke seen on cold or warm start-ups, and pull aways from stop lights, will go away… vs needing to do a ring job. Is that what lead you to do your valve stem seals too?

[roverp480]

I replaced mine that had "O" rings for the lip seals as I was rebuilding the head & it seemed a worthwhile upgrade. I am not sure the the term NADA was still in use by the time yours was built , the relevant parts book doesn't use that phrase, just "U.S.A specification"
Not sure if you have done this before but regarding changing the seals with the head on, you need to remove the valve springs and thus need to keep the relevant valve closed during this period. Just having the piston at top dead centre isn't sufficient. My dealer, when I had the seals changed under warranty, had an adaptor that screwed into the spark plug hole which he connected an air line thus pushing and keeping the valves closed . I have heard of feeding a length of cord through the spark plug hole into the cylinder and then turn the engine compress it all into the top of the cylinder & this hold the valves shut. Having finished , lower the piston and pull out the cord. I managed to change just one broken valve spring using a bent nail pushed through the plug hole , resting on the top of the piston and pushing against the valve. I wouldn't recommend it for doing all eight!

[Elsa]

Thanks for that. I've read about that method with the head on so I'm glad you agree with it, and it worked for you (with a nail). Yes, I think I'll go the rope route . I recently learned it might be wise to first do a compression check, as if the rings are bad then the head has to come off anyway (ugh $$$). More to come... and thanks very much once again for all your great info.

[jimrr]

I seem to recall a lot of leather (with spring) seals on my S3 88 and it was one of the last sold in the usa. I think these were on the valve stems too? and other places, I've saved them somewhere.
P80 !!!, very tricky on the broke spring, I can imagine doing that and not making any fast or extreme moves!!

[roverp480]

I seem to recall a lot of leather (with spring) seals on my S3 88 and it was one of the last sold in the usa. I think these were on the valve stems too? and other places, I've saved them somewhere.
P80 !!!, very tricky on the broke spring, I can imagine doing that and not making any fast or extreme moves!!

The nail was an old rectangular section, not round, so it stayed in place and didn't roll to one side . I have never seen a valve stem seal in leather , road wheel and gearbox shafts etc yes.

[Elsa]

@roverp480, I yesterday checked compression and thankfully results were in range of 130-147. Also checked the Emission Control Valve rubber diaphragm; it's pliable and untorn. So those two areas seem okay. I'm thinking of diving into the valve stem seal job (head on) to conquer the blue smoke at start-up issue (or sometimes at a long traffic light stop). Is there anything else/easier that you recommend checking before I dive in? I realize there's a bit of a wish on a prayer that the seal job will fix the smoke... but trying to eliminate other potential culprits first. Thanks for any thoughts.