Head Gasket

[Nick H]

Hello,
Hopefully some of you can offer me some advise.
Presently my stag is at a local garage with the offside head removed after a blown gasket.
I was going to get them to replace the gasket after first skimming the head and then putting it back together.
They have advised that both heads should be removed and skimmed whilst it is stripped down as only doing one could cause a slight variation and possible leakage at the manifold when it is all re-assembled.
I had the engine rebuilt in 2004 and it has run like a dream since then and I am reluctant to tamper with the nearside head.
Do you think having only one side skimmed will cause a possible leak at the manifold of should I tell them to leave it alone?
I welcome your views.
Nick

[bunny]

Hi Nick
In my opinion if the gaskets were both done at the same time last time, then if one has gone the other can't be far behind.
As for leaking on the inlet i find it hard to understand why it would.
Balance possable but iam not your man for that question.
vince

[flying farmer]

The head gaskets will inevitably fail due to fatigue caused by the different expansion rates of the iron block and alloy heads.

When the cooling system was pressurising on my Stag engined TR a few years ago I had to remove both as I didn't know which one had failed. In fact both had, and in the same place, but one was worse than the other. If I had got lucky and replaced the worse one first it would all have ended in tears a short while later.

I don't think the inlet manifold is relavent, it is how it fits between the heads that is important and that is down to the amount skimmed from the heads, and wether the heads were skimmed parallel to the original face (and believe me I have seen some peculiar combinations of head/manifold interface

Neil

[martin]

The head gaskets will inevitably fail due to fatigue caused by the different expansion rates of the iron block and alloy heads.

When the cooling system was pressurising on my Stag engined TR a few years ago I had to remove both as I didn't know which one had failed. In fact both had, and in the same place, but one was worse than the other. If I had got lucky and replaced the worse one first it would all have ended in tears a short while later.

I don't think the inlet manifold is relavent, it is how it fits between the heads that is important and that is down to the amount skimmed from the heads, and wether the heads were skimmed parallel to the original face (and believe me I have seen some peculiar combinations of head/manifold interface

Neil

I know, I was warned about that 60.000 miles ago, worrying isn't it !

[Nick H]

I know, I was warned about that 60.000 miles ago, worrying isn't it !

Thanks Guys,

I think cost is going to be the deciding factor, but maybe from your comments it would make sense to remove both whilst at it.

Nick

[mike@thenook]

And when they do the skimming make sure they take the same amount off both heads so the distance between the bottom of the cam journal and the head face is the same - any overskim can be taken up by a Savershim made by Gosnay's engineering in Romford Essex - they can supply them to (almost) any thickness needed and importantly take away the problem of the gasket eating into the head again as the shim is stainless steel.
I've learned a lot about this having taken my heads to Gos' but I have another problem with a loose guide they are trying hard to fix before I decide to source some alternatives or (Help!) purchase a whole engine.
Their contact number is 01708 740668 or www.gosnays.co.uk
It is also worth looking under the Technical section - there is a whole load of info in there about tolerances etc.,,

Good luck!

[V Mad]

' but I have another problem with a loose guide they are trying hard to fix before I decide to source some alternatives or (Help!) purchase a whole engine.
Good luck!

A loose guide can be fixed it should not be a big problem. If there is play due to oversize hole in head, it can be reamed and a new oversize guide turned up on a lathe.

[Nick H]

Thanks for the info Mike. Hopefully there won't be any overskim but it's worth knowing where and how I can sort it out if there is.

Nick

[mike@thenook]

A loose guide can be fixed it should not be a big problem. If there is play due to oversize hole in head, it can be reamed and a new oversize guide turned up on a lathe.

This is just what they are going to do - only problem being the guy that does this area of the work is 'a bit' over 70 and doesn't work every day now......

Just imagine this in BL as was!

[flying farmer]

I know, I was warned about that 60.000 miles ago, worrying isn't it !

Yes it is, the head gaskets on the Stag engined TR lasted about 70,000 miles

Neil