Triumphrat

Osara

Hi, I recently bought an accidented '96 Tbird, which I want to convert to a café racer. However when I started the engine, a loud rattling noise came from the cam chain side, and after a short investigation, it appeared that the cam chain rubbing blade was broken in 3 (probably from the shock of the accident). To replace this blade the cylinder head needs to be removed, which I did today without any problems.
My question is the following : Both the triumph service manual and the haynes manual state that the cylinder liners need to be lifted and resealed. Is this really necessary? Has anyone ever tried reinstalling the cylinder head without resealing the liners? I asked my dealer about this, and he told me it was not necessary, but I'd like a second opinion on this :wink:

Thanks, Osara

I haven't removed my head but I don't understand why the manual insists on that. If the liners did lift when you removed the head then it would be necessary to re-seal them obviously.
My opinion is remove the cylinder head and then put a steel straight edge across the the liners and check that they are all level with the top of the cyl block. If they are, then they haven't broken their seal.
The liners are wet-liners so if they are not sealed to the cyl block you get coolant water in the crankcase. I think Triumph are playing safe here and shouldn't be criticised for that.
That's what I would do.

Osara
One more I find myself agreeing with Terry. BUT be very critical with that 'straight edge'.

If there is any sign that the wet liners have lifted or "rocked" , their seals to the cases will probably be split. If so you will always have water & coolant leaking into the oil.

Jon

Jodel

Osara,

I haven't had to take the head off a modern Triumph, but I do have experience of cars with wet liners which were a real pain if you didn't get the seal right. You just end up having to take the thing apart again if it leaks.

It's a fair bit of work to dismantle the engine that far, so you have to weigh up the risk of having to do it again if you get a leak.

As it happens, I'm going to my Triumph dealer tomorrow. If I get the chance, I'll speak to the senior mech. and ask what he thinks. I know he's had a few of these motors in pieces so he might be able to advise.

Cheers.

Jodel

Osara - Update.

Spoke with the Triumph mech today and he reckoned that Triumph recommend re-sealing the liners as it is difficult to be sure you don't break the seals if a liner 'sticks' to the head when you lift it off.

Obviously. if you rotate the crank at all when the head is off, the seals will break unless you can fix some kind of temporary bar across the top of the engine to stop the liners moving.

You might get away with it, but sounds like it's worth re-sealing the liners. Apparently the liners have a distinct taper at the base to make them easier to fit back over the pistons when re-assembling. Hope this helps.

Osara

Thanks for the input everyone.

I reinstalled the cylinder head yesterday. The liners were perfectly level with the cylinder block, but I didn't want to take any risk so I removed them anyway, and I'm glad I did. The tiniest movement will break the seal, and even if they are level with the block, you can't be sure that they haven't moved while removing the head. I was surprised how easy it was to remove and reinstall the liners. They indeed have a taper at the base, so you don't even have to compress the piston rings (well maybe just a little bit by hand), you just "rock" the liners gently over the pistons. Also there was almost no trace of the original seal, but most of it is pressed out anyway when tensioning the cylinder head.
I will probably get her running again next weekend, and hopefully all goes well...

thanks again, Osara

Thanks for the tip Osara; looks like I was wrong on that one then so sorry for my bad opinion. I am concerned that you say there was almost no trace of the original sealant. Looking at the picture in the Haynes manual there is a chamfer at the spigot location in the cylinder block which should hold most of the sealant.
Any chance you took some photos of the installation?

Osara

Don't worry about it Terry, actually I was planning on reinstalling the cylinder head without resealing the liners, but as i was carefully removing some remnants of the old head gasket from the liners, I noticed it didn't take much to slightly move them.
I did take some pictures of the block with the liners still installed, block with liners removed, and the liners themselves. If you're interested I'll try to set up an album here.
I can also add photos later of my next projects : I still have to replace the starter clutch on my 2nd Tbird (at 112.000kms), which requires the crankshaft halves to be separated, and I need to do something about the oil consumption of my trophy (also at 100.000+ kms), which also requires cylinder head removal...After that I should be safe for a while :-D

Thanks Osara. I'm always interested in looking at pics of jobs like that. It may be my turn next so I'm happy learning something from the guy who did the job before me.
Sounds like you did a good job.

Osara

Hi Terry, I finally had some time to upload the pictures of the cylinder head removal to my album. You can find them on this link