Valve stem seal installation

[CaptainAhab]

Hi guys, I'm rebuilding the head after de-coking and valve lapping etc. I am installing new valve stem seals and want to be sure they are in right, but I'm not sure of how much pressure to put them under. I have heard there is a measurement between the top of the seal and the top of the valve stem, does anyone know this figure?
I'm using a small plastic tube to push them down by hand and I've stopped pushing when there is a lot of resistance. It would be a bit of a bugger if they came off after the head is back on.

Cheers,


Rob

[morsing]

Hi,

Not sure about the Volvo, having not done this on a Volvo, but on my other car they will just get pushed back when the valves start moving anyway. Is that not the case here?

Thanks

[CaptainAhab]

Hi Henrick, these seals are a push fit over the intake valve guide, there is a small spring around the top to seal onto the valve stem. Once in they are not supposed to move or alter shape.
I am reasonably happy there are on right as any more pressure feels like it would damage them, but if they lift off afterwards I'll have to take the head back out again so I thought I would check now!

[morsing]

Hi,

I know what they look like, I've had a set lying in the garage for a year waiting for me to have time to fit them :-)

Maybe I should just get started on doing it...

[CaptainAhab]

Ha, yeah, I have various items in similar situations!

I took the opportunity to de-carbon everything, grind the valve seats, set the shims and put in a V cam. It got rid of a few items from The Shelf.

[Clifford Pope]

As I recall, the seal is like a little rubber bucket with a rim and spring around the wider end. Don't you just press it down until the rim engages in the groove round the top of the guide?

I did them once long ago with the head on and used the rope trick. I remember it would have been possible to press the seal down hard so that it rode up the guide beyong the groove, but decided that would have been pointless because it clearly didn't want to stay there and would have moved back up to click into the groove anyway when the engine started.

I don't think there is space for it actually to come off the guide is there - wouldn't the underside of the big plate holding the spring keep it on when the valve opened?

[CaptainAhab]

Hi Clifford,

There is room under the spring retainer for it to lift, and I've seen forum posts saying they weren't put in right and came off.

My shim comes in a couple of days and I'll be firing up shortly after, I'll keep you posted!

[morsing]

You never kept us posted! :-)

I did mine last summer if you want to compare notes and it's been running like a dream... So smooth.

Regards,
Henrik