17 replies to this topic

[sam138]

I’ve recently swapped cylinder head to a mini spares Mse 4 head which is weeping coolant after torquing down. The old cylinder head had no problem with leaks. Is it possible to do a in situ head skim at home as I guess this is what is needed to get the block flat ? Or does it just need a better clean up ?

[TheFabMini]

I’ve recently swapped cylinder head to a mini spares Mse 4 head which is weeping coolant after torquing down. The old cylinder head had no problem with leaks. Is it possible to do a in situ head skim at home as I guess this is what is needed to get the block flat ? Or does it just need a better clean up ?

I had the same problem when I changed the head gasket on my standard 998
Had a weep between the head and block after fitting a cheap copper gasket
Removed that and done a much more thorough clean up and fitted a composite gasket and not had any leaks since. Also improved compression slightly

[macaldron]

If its a new head gasket then they have bewn known to leak if using coolant straight away. I just changed my head gasket and foe got this tip. Leaked out the coolant. Took it apart, cleaned again, filled just w water and have a perfect seal now. Will run just water for a month or so then will change over to coolant (30%). Several posts popped up on this topic when I searcged a few days ago. All point to needing to run water first then switch to coolant.

[sonikk4]

Did you retorque the head after one full heat cycle??? Also there are some poor copper hg's out there.

 

I had this issue on my clubby. Head was flat as was the block. Ended up using a Payen HG which cured the problem.

[Rorf]

There are head gaskets and head gaskets - usually the more expensive the better the quality. Head and block surfaces need to be scrupulously clean. Another trick is to start the engine without coolant until the head is warm to the touch, switch off and only fill with coolant the next day.

 

Also do not over torque the head bolts.

[sam138]

Thanks for the reply’s. I’m using a bk450 head gasket which I’m led to believe are the best ones. I’ve only torqued the head down and filled it with coolant but not started. Came out the following day and could see weeping between head and block.

[sam138]

I guess a further strip down and clean of block again is in order. Is the gasket I’ve used a suitable choice ? I will then try the water instead of coolant method if that’s the best course of action ? Can I ask why this is ? Does it allow the head to seal better after first cycle.

[petey81]

I had the same thing a few years ago when i fitted another head. I filled it up with water for a week or so then used coolant. Been fine for 5 years...

[sam138]

From the pictures attached would you say this is clean enough ?



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[sonikk4]

It’s not so much the cleanliness but more the fact the mating faces are true and flat.

Use a 12” steel rule or 24” if you have one to hand and run the edge over both the face of the block and the face of the head. You should not see any light other than chambers etc. It’s a rule of thumb more than anything and not as good as actually having the faces skimmed etc.

The fact that the head is new you would like to think that is true and should not be an issue.

The fact that you did not do a full heat cycle and re torque will not have helped either.

Another thing is the Torque wrench. Is it new or an old one that’s been laying around??

[Rorf]

BK450 head gasket is great, the head is newly refurbed so should be flat and it would be unusual for the cast iron block not to be flat and true. Torque it all up and only add water just before you intend to start it up for the first tme.

 

Check that the head suds have not stretched which would also be unusual for a mini engine.

[sam138]

Thanks for the reply’s, I’ve got a torque wrench which is only a few months old and have been torquing down to 68nm. I’ll get a flat edge on both items before i refit up with a new gasket.

[sonikk4]

I have to say when i did a HG change on my 998 clubby engine that leaked even after a full heatcycle and re torque.

 

Head was flat as was the block face, studs were not stretched etc etc. However i used a Copper HG. So i decided to keep running the car as no oil / water was mixing, just leaking around the edges.

 

It did a couple of long journeys with no problems but i did have a word with Simon@minispares and he sorted me with a Payen hg and no issues after that..

[sam138]

Thank you very much for all your help. I fitted up the gasket today and run it for 40 second TIL head warm without coolant which seems to be recommended to allow the gasket to seal. Then filled with water and down a full heat cycle and re torqued and no leaks !!

[sam138]

Thank you very much for all your help. I fitted up the gasket today and run it for 40 second TIL head warm without coolant which seems to be recommended to allow the gasket to seal. Then filled with water and down a full heat cycle and re torqued and no leaks !!