Leaking head gasket

[chenstone18]

Having recently had my 7's head and block machined I reassembled the engine and put it back on the chassic. I then did a pressure test and found that cylinder 1 was leaking and giving me no pressure at all. I could hear the leak as I manually turned over the engine and it appearred to be leaking in to the timing chain casing. Because it had a lot taken off the head I fitted a extra thick gasket and applied the torque settings as for a standard one. The valves and guides had been replaced and to the best of my knowledge do not leak. I have also new piston rings fitted.
So the question is why does it have no pressure in cylinder 1?
Have I tightened it up enough as do extra thick gaskets need more torque?
Should I have put gasket sealant on it before I assembled it
Any help would be appreciated







  

[Beans]

Presuming that with pressure test you mean a compression test, I would first check that all valves close properly.

A problem that can be caused by the fact that a lot of material has been skimmed from the head are the five angled head studs.
When skimming a lot of the head, the holes in the head and block won’t align properly anymore.
As a result of which tightening down the head properly might be a bit of a problem.
So these holes might need enlarging a little.

When you used the correct torque settings and sequence it should seal properly without adding more torque.
And don’t use gasket sealant on the head gasket

[Nick Jones]

^^^ WHS.

The angled studs can hold the head off if the right technique is not applied, especially if the head has had a big skim.  I once managed to have an 1850 head torqued fully down according to the bolts torques which poured water out of the gasket face as soon as we started filling the engine with water.  That caused a few oaths!

On the advice of a local Stag specialist we lifted the head again, gave all the stud holes a really good clean out and relieved the angled stud holes near the face .  We then re-assembled by initially leaving the straight studs loose but nipping up the angled ones working from the centre outwards while thumping it fairly gently with a rubber mallet in the direction that the studs run.

The angled studs were then slackened and the book torque procedure followed.  Worked fine that time.

Astonishingly stupid idea those angled studs......

Nick

[Flying Farmer]

When you say you had the block machined, was the deck of the block skimmed, because if it was the timing cover should have been bolted in place when it was done, otherwise there will be a step that will hold the front of the head off the block
Neil