Loose valve guide

[Paul Goldsmith]

I've just had the diagnosis that the noise from my offside head is due to a loose valve guide

Both heads where rebuilt about 6 years ago at a respected Stag specialist and the car has done only a couple of thousand miles since (mainly due a lay-up these last couple of years). Due to unavailability of a decent MK2 head at the time, a reconditioned MK1 head was used on the offside. The longer term plan was always to keep an eye out for a better pair of MK2 heads but as the car had been running fine prior to its lay-up this search lost focus.

From searches on this forum, there has been suggestions that a loose valve guide has sometimes be sorted with the head in-situ but no further information provided. Please can somebody enlighten me further on possible options ?

At this stage I'd be happy with possibilities for even a 'stop gap' repair on the MK1 head, to buy me some time resuming the search for a better pair of MK2 heads. I'm visiting the garage on Saturday to be shown for myself, will take pics and post if that helps here.

Many thanks

(BTW : I've still got my original MK2 head, which was rejected due to the skim being down the valve seat IIRC)

[73stagman]

You can get a bespoke valve guide made. The valve guide hole will need to be reamed to make sure its truly round then a bespoke valvguide machined and reamed itself to suit the valve stem. I have one to do in one of my rover heads too! Its not rattling at the moment but it was pretty loose when it was fitted

[Staggard]

I am not suggesting you do this, but I guess you could remove the camshaft remove the spring ( using the rope trick) from the offending valve/guide remove the guide over the valve stem and replace the guide in reverse order with a bespoke or original. Normally when you replace guides they trim the seat to make sure the valve sits square. The problem this a very dangerous area EG the guide loosens drops down jams and stops the valve closing then what follows does not bear thinking about OH PS you may be able to use a head saver shim on the Mk2 head

[Staggard]

Right I have just got my P45 Got it wrong the guides cant drop down because they are shouldered. But I think the consensus would be not to go down this route. I should have remembered that as I have just done my heads, now where did I put that bottle of Vodka

[staginhiding]

As far as I know the Head needs to be heated to replace the valve guides properly..so an in situ repair would not work..
Unless someone else knows any different..

Sam

[Staggard]

As far as I know the Head needs to be heated to replace the valve guides properly..so an in situ repair would not work..
Unless someone else knows any different..

Sam

An old immersion heater and a pump,

[Paul Goldsmith]

Many thanks folks, so it's theoretically possible but only just ! Laterally thinking, instead of heating the head to expand the hole, couldn't the guide be frozen to make it smaller ?

I'm also wondering whether there's a heat resistance bonding glue to hold the guide in place ? Appreciate that it might not last forever but buy some time for a better MK2 head to be found. I''ll know more tomorrow lunchtime when I pop over to have a chat with the mechanic and update what the confirmed diagnosis is

I did ask about 'saver shim' on my over skimmed MK2 head at the time but this was ruled out IIRC because the rebuilder wasn't keen in principle.

[Staggard]

Many thanks folks, so it's theoretically possible but only just ! Laterally thinking, instead of heating the head to expand the hole, couldn't the guide be frozen to make it smaller ?

I'm also wondering whether there's a heat resistance bonding glue to hold the guide in place ? Appreciate that it might not last forever but buy some time for a better MK2 head to be found. I''ll know more tomorrow lunchtime when I pop over to have a chat with the mechanic and update what the confirmed diagnosis is

I did ask about 'saver shim' on my over skimmed MK2 head at the time but this was ruled out IIRC because the rebuilder wasn't keen in principle.

Hi Paul, The heated ally will expand far more than the frozen guide will contract, as far as saver shims go, true to say I have never used them myself but I am sure there are quite a few that have. Why don't you drop Kryten) a PM see what he thinks he is a fairly helpful geezer and his knowledge is current. Cheers Graham

[V Mad]

As far as I know the Head needs to be heated to replace the valve guides properly..so an in situ repair would not work..
Unless someone else knows any different..
Sam

I believe the 'correct' method is to press them in cold, although this seems unusual preactice.

[staginhiding]

I believe the 'correct' method is to press them in cold, although this seems unusual preactice.

I'm just going on what my machine shop said to me,so I'm probably wrong again....

Sam

[V Mad]

General workshop practice is to shrink them in, but for some reason the stag heads are supposed to be pressed in cold (I dont have any reference to where I read this though).

[DJT]

From ROM:

[73stagman]

The ones for the Rover heads suggest that the heads are heated and the guides are chilled.... so best of both... means everybody is right!

[jleyton]

General workshop practice is to shrink them in, but for some reason the stag heads are supposed to be pressed in cold (I dont have any reference to where I read this though).

Maybe Triumph were worried about overheating the heads

I wonder why

Cheers

Julian

[V Mad]

Maybe Triumph were worried about overheating the heads

I wonder why

Cheers

Julian