Cylinder head removal

[Ken Young]

I need a bit of help and advice please. I've got a poor compression on one of the cylinders on my GT6 mk1. I am taking the head off and following the instructions in Haynes.  It specifically says to leave the manifolds in place during removal.  However, as far as I can see, this prevents access to the head fixing bolts.  Am I missing something here. I've added a photo on case it helps. Thanks. Ken

[Ken Young]

Here is the photo

[nicmk1est]

you have to remove the manifold,think the manual refers to a later engine,you`ve got early type

[Ken Young]

Thanks nick. I'll get back to work.

[JohnD]

In all versions of all Triumphs of this era, four or six pot, the manifolds bolt to the head.
So it has to be unbolted, to get the head off.

In fact I'd have to think for a very long time to find an engine where the manifold doesn't bolt to the head.

Without rereading the Haynes text, I think it means that you need not remove the manifold from the engine bay, which requires that you dismantle the exhaust system first, just to push the manifold aside and leave it there.

JOhn

[JensH]

Quoted from JohnD

In fact I'd have to think for a very long time to find an engine where the manifold doesn't bolt to the head.

Yep - you will have to go electric for that
And then... no manifold ...

[RobPearce]

Quoted from JohnD

In fact I'd have to think for a very long time to find an engine where the manifold doesn't bolt to the head.

Quoted from JensH

Yep - you will have to go electric for that

Umm... sidevalve, anyone?

[nang]

Relatively easy to just undo the manifold bolts, leave the exhaust alone, and push the manifold away. That's what I do. Saves having broken exhaust studs and the drama that goes with it.
Tony.

[Ken Young]

Good old Haynes. Anyway, I think I found the problem. Quite relieved it's not the rings or valves.

[glang]

ummm yes that would explain low compression although I would have expected to find it on both cylinders. Anyway I suppose you'll check the head for flatness and also grind the valves before reassembly?

[Nick Jones]

Good ol' Mk1 and it's "fun size" head studs........

Nick

[Ken Young]

I am just about to order a replacement head gasket and am slightly bewildered by the alternatives on offer.  I don't want to fit a crappy one accidentally.  Can anyone recommend a good supplier / make.  Thanks

Ken

[JohnD]

As Nick says, a Mk1 head - all the ports in a line, not staggered.

You need a gasket without the recessed ring and without a tab at the back, which would mark it as a MK.II gasket.
As for maker, Payen ones are a good name.   Your old one looks to be an original copper/white asbestos one, so dispose of it correctly - take to the tip and tell them - asbestos!
Payen have a heat activated sealant on both sides, and seal well.

But investigate why your old one blew.  As above - damage to head or block faces?
John

[Ken Young]

Thanks for the advice John. There is nothing obviously wrong with the sealing faces on the block or the head.  I have cleaned them up and they seem good and flat with no dents or dings.   The only thing I can think of is that the bolts loosened over time due to creep. The head nuts located under the manifold were certainly a bit looser than I would have expected.  

Is there any check that  I can try in the garage that doesn't involve specialist equipment.  Also are there any other known problems that may have caused this that I can check.  

Note also, the fitting of the stainless coolant feed pipe that goes under the manifold was fairly badly blocked with rusty shite. That may have restricted cooling, although I think this is not for the head but for the air manifold and heater matrix.

[JohnD]

Place a straight edge - a steel rule is best - on the surface to be checked and shine a bright light from the other side.    This will show up any irregularities in the surface well.

That coolant pipe is the return from the heater.    It was originally mild steel, so if you have a stainless one, plus!   But if that is furred up then think on what the block water jacket and everywhere else is like.   Dipping the block, stripped of all components is ideal but otherwise have a dig down the rear right hand side towards the drain plug/tap. This is the deepest point of the jacket and often has a lot of crud deposited so that often the drain is completely blocked.    Dig it all out with a long screwdriver.
Then use a coolant system cleaner when the engine is reassembled with the radiator in place.

John

[RobPearce]

Mk1 head gaskets can fail like that due, as you suspect, to the "fun-size head studs". While there's absolutely no harm checking it's all straight, the odds are it's fine. You would do well, though, to replace all fourteen head nuts with ones from MiniSpares (comes up fairly frequently, this one).

[Ken Young]

I am now ready to do a rebuild after having invested in some new high strength flanged nuts and a Payen gssket from jigsaw racing. Some detailed questions.  

1) When I rebuild, do I do all the nuts up reasonably tight before torquing up or should I just leave them finger tight.

2) should I apply copper slip to the threads or just engine oil?

3) with flanged nuts, should I still use washers?

Thanks.

Ken

[Andy Flexney]

Ken,

once finger tight I start using the torque wrench at a low setting, usually about half of the final setting and tighten in sequence. I then repeat this 3 or 4 times making the added torque smaller each time. For the TR3 the setting is about 110 lb/ft so I start at 50, then 80, then 100, then 105 and finally 110. It seems to work for me.

I always make sure the threads are clean and I put a drop of normal oil on them to ensure there is as little friction as possible. I have never used flanged nuts but I presume if you do there is no requirement to use washers.

AndyF

[Velocita Rosso]

Quoted from Ken Young

I am now ready to do a rebuild after having invested in some new high strength flanged nuts and a Payen gssket from jigsaw racing. Some detailed questions.  

1) When I rebuild, do I do all the nuts up reasonably tight before torquing up or should I just leave them finger tight.

2) should I apply copper slip to the threads or just engine oil?

3) with flanged nuts, should I still use washers?

Thanks.

Ken

If you get the ARP stud kit ,the set of instructions you get will explain how to set the allan key ended studs and multi point socket head nuts fitting along with a special lubricant. These kits are far more effective than the standard bolts/nuts
http://arp-bolts.com/
Payen gaskets are a must

[Jonny-Jimbo]

Yup, I think it's on the ARP site, and certainly in a set of ARP bolts I had a while ago, the type of lube you use changes the torque setting needed - as it changes the friction.

Quoted Text

Three basic elements that contribute to the friction factor:
Most importantly - The fastener assembly lubricant

http://arp-bolts.com/p/technical.php

The higher the friction the LESS able you are to reach the correct torque - so you don't want to go in dry. However, if you use oil, and use too much you can hydraulic lock the stud / bolt and never reach the correct torque, but this is only the case if it's in a blind hole.

The most consistent lubricant is the ARP lube, then Moly and EPL grease, and oil is the least favourable...

Pays your money and takes your choices.

[Andy Flexney]

Mr Rosso, Mr Jimbo,

"special lubricant" ?
"allan key ended studs and multi point socket head nuts" ?

erm? you do remember we are talking about triumphs here. Isn't all that a little over the top for a MK1 GT6?

AndyF

[Tim Bancroft]

No need for all that fancy ARP stuff, I am sure the flange nuts that you have bought from Mini Spares or Jigsaw will be sufficient.

Torque setting for mk1 engines is low, not surprising considering the small diameter of the studs and nuts.

I helped James Cooper the other day torque up the head nuts for Ben Hutching's mk1 and I was surprised at the low figure. Even then using his high quality torque wrench we were worried that they would strip!

Don't many when having work done to a mk1 engine get them drilled and tapped for mk2 size studs? Seems a good idea to me.

[Richard B]

Quoted from timbancroft61

Don't many when having work done to a mk1 engine get them drilled and tapped for mk2 size studs? Seems a good idea to me.

Yes but, you have to drill the head as well.


I think so long as you use the hardened nuts, (not the 8.8 common or garden ones) your ok.

Of course if you are tuning, hot cam, flowed head etc then you may well want more than 46lb/ft on the head nuts.

[Velocita Rosso]

Quoted from AndyF

Mr Rosso, Mr Jimbo,

"special lubricant" ?
"allan key ended studs and multi point socket head nuts" ?

erm? you do remember we are talking about triumphs here. Isn't all that a little over the top for a MK1 GT6?

AndyF

...because of the crap stuff being sold from retailers and the numerous stripping of threads on nuts and studs whilst tightening the first turns. arp...no problems whatsoever

[Marc F]

So washers with flanged nuts or not?

I am building my Spit and bought uprated from James Paddock but they also supplied washers so mucho confusion here