1098cc Valve seals

[Wyliecoyote]

Having some bother refitting the valves to my cylinder head on the 1098cc

Can someone show me a oicture or diagram of which order things go back on?

I have new spring-type seals but the conical type thing beneath the retaining ring seems to snag the top of the seal

Any help or pictures appreciated

Thanks

[bmcecosse]

You just push them down the valve stem till they sit over the guide. If the guides don't have a groove near the top - they may not stay in place for long.

[simmitc]

As Roy says, if the guides have no groove, then the new seals won;t work very well. They are really good when fitted to the matching guides; but the original plain guides had just an O-ring seal on the valve stem. There is a good reason why the design evolved

[philthehill]

Your best bet is to fit 4 new inlet valve guides (Pt No: 12G1963) with the groove seals (Pt No: ADU4905). You may need to shorten them on the non grooved end as the 1275cc valve guides are slightly longer.
The conical thing as you call it is the valve seal shroud (Pt No: 2A545) and is not required when fitting the later seal.
Some say fit the new seals to all 8 valve guides and some say only to the inlet valve guides but I would suggest fitting only to the inlet valve guides. A bit of oil around the exhaust valve stem is no bad thing.
Attached is a photo of the non grooved valve guide (top) and the later grooved valve guide (bottom) and the special tool required to fit the valve guide though with care the tool is not required. Make sure that the top of the valve guides do not protrude above the valve spring seat more than 19/32".
Also attached is a diagram of the current valve seal arrangement.[frame][/frame][frame][/frame]

[bmcecosse]

I wouldn't fancy trying to fit new guides without that tool! And yes - I had to shorten them considerably to avoid obstructing the inlet throat....

[Wyliecoyote]

Thanks guys great help, much appreciated!

[alexmcguffie]

If you do end up fitting new valve guides they should then be reamed to the correct size and then the valve seats re-cut and ground in. If you're going to do it, might as well do it properly ;)

[philthehill]

Whilst you may have to recut the seat relative to the new valve guide it may not be necessary; lightly lap in the valve against the seat and see what the result is - a nice grey lapped in finish all round on both valve and seat will be all that you require. If you cannot get that finish the valve seats will need to be recut and lapped in. If you have engineers blue to hand you can do the same test and see what results you get.
As regards the fit of the valve in the guide again you may not have to ream the guide. Fit the guide and see what the fit of the valve stem is in the guide. I find that the majority of valve guides these days do not need to be reamed but it is important that the valve is not tight in the guide.
The above is worth trying before buying any specialist tools.
If you are not experienced in the ways of fitting valve guides/cutting valve seats and reaming valve guides it may be better to give the job to your local engineering shop to complete but of course that will cost money.
Good luck
Phil

[bmcecosse]

I recently fitted new guides to a head - I can confirm NO need to ream anything - what can sometimes happen is that the top of the guide may be slightly damaged -especially if the 'tool' isn't absolutely square... This was not the case for any of mine (and they were a bl**dy tight fit in the head...). Valves dropped straight down no problem. I've never understood the often stated 'need to recut the seats'. Assuming the new guides are properly made - the centre hole concentric with the OD - then the valve will drop straight on the original seat. Again - this was fine in my case. As it happens I am recutting the seats - but because they were pretty badly pitted...not for any concentricity reason.