Valve Stem Oil Seal Replacement

[lotuska]

Started to get blue smoke when decelerating and on inital startup, think it could be the valve stem seals (compression fine, no horrible noise).

Has anyone managed to replace the valve stem oil seals without removing the head?

If so what tools did you use?

[Specky]

I'm guessing you're on about doing the compressed airline trick in the top and putting on new valve stem seals...

I've only heard of steve williams doing it..


If you get no joy here give him a bell..

TTFN

[Enright]

I wouldn't have thought it was possible.
But if anyone can demonstrate otherwise I'd be fascinated.

[dapinky]

In theory it is possible, but you will need some specialist kit to do it!

Basically, by removing the sparkplugs, an addapter is threaded into the hole and then (with the cams out, all of the valves will be closed) compressed air is put into the combustion chamber to hold the valves shut, then a speciall type of valve spring compressor bolts to the cam mountings, allowing leverage down on each spring to remove the collets spring and caps. then the seal can be replaced.

I have tried it once on a different engine, but it is a long and fiddly job and (certainly on other cars) it would be quicker to remove the head.

It is the sort of proceedure more suited to one or two seals which need replacing, rather than the whole lot. If they all need doing, it would probably be best to strip it all down so the valve to stem clearances can be checked and the valves re-lapped.

For the cost of the equipment needed, i would suggest either buying a head gasket set and doing the lot, or if you dont want the hassle, try and hire some kit, or farm the job out to a good garage.

Good luck with whatever you go for!

[lotuska]

Looks like I've got a challenge...what I was planning to do was strip the top end and then use one of the two following tools (The draper one I've seen for £45).

Or maybe knock up something myself to do it...I've heard that you don't need to use compressed air to hold the valves in place, some rope fed down the sprak plug hole would do...obviously need to keep hold of one end!!.

[dapinky]

Or maybe knock up something myself to do it...I've heard that you don't need to use compressed air to hold the valves in place, some rope fed down the sprak plug hole would do...obviously need to keep hold of one end!!.

Mark, sticking a bit of rope down the plug hole is one of the 'recognised bodges' that usually works (but not as well as the compressed air!)

The potential problems with that technique are that you need a fair length of thinish rope which is pliable enough to fill up the cylinder (a long and boring job - but i've done it so i know it works!). Its worth using natural fibre rope if you can, and soak it in oil first.

If it's too thin, then it can get caught between the valve and seat.

If you go for it, then set the cylinder to 90 degrees or so , feed the rope in, and when it feels full, turn the engine by hand to hold the valves in place as the piston rises.

another potential problem is that it is possible (but not too likely) that the valve you are working on can drop a few mm because the rope is not acting on that valve as squarely as the others (does that make sense?.....well, i know what i mean ), in which case, when it comes to reassembly, unless you put the pressure squarely on the valve spring cap, it can be fiddly to get the collets back in - it all depends on the tool you use, hopefully there is enough clearance to pull the valve up a bit when the spring is tensioned to allow the collets to drop into their grooves.

The tool i used for mine and Pauls engines i made up out of a piece of thick-walled hollow tube, a couple of washers an angle grinder and a MIG welder! it took about 20 minutes, and worked alright for us! I'm sure that a suitable tool can be made for the method you want to use.

Good luck!

[GeoffSmith]

an angle grinder and a MIG welder!

F**k me! How do you get them in the cylinder?

[lotuska]

Dave,

Thanks for the advice...and yes it does make sense...

Was going to butcher an old spark plug and weld a quick release air line fixing onto it so that I can connect my compressor up.

Also spotted this on ebay, thought it looks like something I could fabricate fairly quickly:

[dapinky]

Looks like a suitable tool, and quite easy to knock up.

Having just done mine the conventional way, the only extra advise i can give is that the valve springs on the elan are quite deeply inset into the head, and it needs the bit that sits on the spring to be quite long (on the honda tool, i think you would need to space the 'base bar' up from the cam bearing caps with a suitable spacer to give you enough room to manoevre the fiddly bits. Getting the collets out is easy using a magnet, and getting them back in can be done with a dab of grease on the end of a thin screwdriver.

One more thought, don't forget to work on the pistons which are up the bores, not down the bores, just in case there is a catastrophic air leak and the valves drop into the bore!

[lotuska]

Made a start today on stripping the top of the engine, took some pics to show progress.

Has been a while since I'd changed the cam belt and had forgotten what a bugger it is.

I've decided that as it's stripped I might as well replace the cam belt, I've got both bearings out (ones the tensioner) how do you tell if they are knackered? (they spin freely, with a little movement, and when spun make a slight noise)

[lotuska]

Done a little more searching on the site and several people have suggested that you can swap the bearings in the tensioner and idler.

Don't suppose anyone knows the numbers for the bearings?

[Enright]

Cor, big job to start just a week before Donington.
Can't it wait til after?
I suppose not now.

[dapinky]

Done a little more searching on the site and several people have suggested that you can swap the bearings in the tensioner and idler.

Don't suppose anyone knows the numbers for the bearings?

I don't know that the bearings can be changed on their own - the ones i got were all sealed units.

They are about £50 each at SJs, but i got mine from America (Rockauto.com) at $67.67 inc shipping - DAYCO part number 84103.

They take paypal and took about a week to arrive (probably not in time for Donny ).

I tried DAYCO in the UK but got no joy from them, so went direct to rock auto.

(Their cam belts are about 16 bucks as well - damn site cheaper than over this side of the pond!)

[Dico]

I looked into changing just the bearings but gave up the search.
If there is a slight noise you may be best changing them. I know it adds to the cost but at least you are saving on labour.
Good on you for having a go

[Monty]

Some info here

lotuselancentral.com/forum/viewtopic.php?t=5998

[lotuska]

Bad news today...

I made up a tool that would allow me to compress the valve springs (looks like the Lotus original) and also butchered a spark plug to allow me to pressurise the cylinder (to stop the valves dropping in).

Connected the air line to number 1 cylinder...a strange gurgling noise could be heard and then an fountain of water started to errupt from the expansion tank...damn, looks like I've got a blown head gasket.

Tried the other cylinders, no gurgling or water fountains...

Oh well, anyone know where the best place to buy a head set is?

[Enright]

I think Sy might have one at a pinch, but otherwise get in touch with Michael (KMCKMC) to send you a set - £60 + P&P.
See this thread - they are unbeatable.

[dapinky]

Looking on the bright side.....you've found a new way to check for head gasket failure - it's not one i've seen before!

And now you can do the whole lot easier on the bench.

And you've also established that the cylinders aren't slack in the bore, otherwise there would have been air getting past the rings into the block.....

...and you've got time to order the belt and tensioners from USA (cheaper) - probably worth a water pump aswell whilst you're at it.

See, if you look at it like that, it was quite a sucessful day

[Sy V]

ka

If you need a gasket set, I have a spare you can have, as long as it's replaced.
oh seven eight one oh, eighty-eight, thirty-nine, forty-one.

[Enright]

Eighty-five, thirty-five, thirty-six... hut-hut-hut!

PS Sy, hope you didn't mind my throwing your name into the frame there. I just thought I remembered you recently offering similar to someone else, and noticed that Lotuska was in Redditch.