16 replies to this topic

[Brewster]

Hi folks, I'm new to the forum and would be grateful for any assistance. I recently discovered a small leak from the cylinder head gasket in my 1979 Mini Clubman 1100. The cylinder head was removed and sent away for refurbishment, and at the same time converted to run on unleaded fuel.

The top of the engine block was cleaned up prior to reassembly with new gaskets and studs. Prior to reassembly I checked for any deformation of the top of the engine block. Following the settings within the Haynes manual I torqued the new head bolts. Within a space of approximately 10 seconds it became apparent that there was a water leak from the head gasket, just below the thermostat housing on the cylinder head. After switching off the engine and allowing it to cool I rechecked the bolt torque settings, and confirmed they were all set at 68Nm. After stripping everything down I then spotted a couple of holes in the new head gasket which did not appear to have a corresponding hole on the top of the engine block, which I suspect to be holes for the water jacket that may have become blocked. I'm not sure if this could be related to the water leaking from the head gasket, but if anyone has any advice then it would be greatly appreciated.

I've attached a couple of photographs with the suspected blocked holes indicated with arrows.  ir-IMGP1301.JPG   71.4K   28 downloads  ir-IMGP1303.JPG   65.36K   25 downloads

[tiger99]

That is quite normal. Some variants may have drilled holes there. But if in the slightest doubt, poke the centre of the suspect areas with a sharp tool. I expect that you will find it is solid cast iron.

As for the leak, did you remove the head studs and lightly use a countersink or large drill to clean any raised burr or debris from around the holes? And what brand of gasket did you use? It is hard to know what else to suggest unless the block or head is warped, which can unfortunately happen.

Have a close look at the gasket that apparently failed. There may be some visible signs of problems, which may help diagnosis. You could perhaps put the same gasket back for a quick check, to see if the leak really is where it seems to be. Sometimes coolant or oil escapes somewhere else and runs around the small ledge formed by the gasket edge.

[Rorf]

First problem - torquing head bolts to 68Nm you have probably stretched them. Shouldn't be more than 55 Nm and torqued in correct sequence and in three stages.

 

What head gasket did you use - Payne are one of the better ones.

[Dusky]

68nm isn't too wrong, my book says 68nm for all engines except those with emission controls (literal translation) which should be torqued to 54nm.

[Brewster]

That is quite normal. Some variants may have drilled holes there. But if in the slightest doubt, poke the centre of the suspect areas with a sharp tool. I expect that you will find it is solid cast iron.

As for the leak, did you remove the head studs and lightly use a countersink or large drill to clean any raised burr or debris from around the holes? And what brand of gasket did you use? It is hard to know what else to suggest unless the block or head is warped, which can unfortunately happen.

Have a close look at the gasket that apparently failed. There may be some visible signs of problems, which may help diagnosis. You could perhaps put the same gasket back for a quick check, to see if the leak really is where it seems to be. Sometimes coolant or oil escapes somewhere else and runs around the small ledge formed by the gasket edge.

I have poked the area with a centre punch and it does seem solid, so I will leave it alone.

The head studs were removed, but I didn't countersink the holes, so I will do this when I reassemble.

I bought a head gasket set from Minispares, which contained a basic copper gasket. I have now ordered a replacement one from Minispares which is advertised as being the best one available.

There doesn't appear to be any sign of damage to the old gasket, but I will inspect it further.

Thanks for the advice regarding the stud bolts, I will give that a try

[Brewster]

First problem - torquing head bolts to 68Nm you have probably stretched them. Shouldn't be more than 55 Nm and torqued in correct sequence and in three stages.

 

What head gasket did you use - Payne are one of the better ones.

Unfortunately I used a basic copper one which was part of a head gasket set supplied by Minispares. I have now ordered the better quality Payne one.

The torque settings I followed were the ones specified in the Haynes manual, but were only in two stages.

[Brewster]

68nm isn't too wrong, my book says 68nm for all engines except those with emission controls (literal translation) which should be torqued to 54nm.

Thanks Dusky, I have double checked my Haynes manual and it definitely states 68Nm.

[panky]

Yep it says 68 Nm or 50 lb/ft

[cal844]

68 NM is too high! 45nm is the update I believe?

[Dusky]

68 NM is too high! 45nm is the update I believe?

45lb/ft when you oil them AFAIK. Calver has an article dedicated to it 😊

[RooBoonix]

http://www.calverst....asket-problems/

 

Here is said article, he mentions 45lbft dry on standard studs and nuts.

[Dusky]

http://www.minimania...t_problems_1227

"2 If standard spec studs/nuts are used, do them up with NO lubrication to 50lb ft. If you must oil the threads, do them up to 45lb ft, or if using a moly-based oil, 42lb ft."

He needd tot make up his mind

[RooBoonix]

http://www.minimania...t_problems_1227

"2 If standard spec studs/nuts are used, do them up with NO lubrication to 50lb ft. If you must oil the threads, do them up to 45lb ft, or if using a moly-based oil, 42lb ft."

He needd tot make up his mind

 

I think as long as you use an adequate torque (which seems to be between 40 and 55lbft) and stick to that number, to keep the clamping force needed, then you can't be too far wrong..

[Brewster]

http://www.calverst....asket-problems/
 
Here is said article, he mentions 45lbft dry on standard studs and nuts.

Thanks chaps. Studs and bolts were replaced, so will torque them up dry as suggested to 45lb/ft

[MRA]

Ok there seems to be confusion.....

 

1) the older studs unmarked are 40lbf ft

2) the later type with a "Y" on top are 50lbf ft

 

Both should be dry, but if you oil them reduce accordingly