9 replies to this topic

[sam138]

Just needed some advise if possible please, I’ve noted on my 1275 supercharged mini that the head gasket is leaking oil on the back edge ( clutch side) after bringing the vehicle
up to temperature.

I’ve only just got the car up and running and it’s running quite rich which I’m trying to sort out however would the head gasket cause a small amount of grey / blue smoke under throttle at idle 3-4000 RPM ? Or could this be a combination of both with oil leaking into combustion area ? I’m running a decompression plate with two head gasket and it looks to be leaking between the head and first gasket.

I’m going to run a compression test however I just wanted to confirm the piston rings are not at fault here as well. I’ve managed to purchase one of the Cometic head gaskets which I’m going to try as it seems a few people have had oil leaks with decompression plates.

Edited by sam138, 22 December 2021 - 07:44 AM.

[sonikk4]

First of is have you done a retorque of the head after it’s first full heat cycle?? If not then check now.

Now what head gaskets have you used, copper or composite?? Copper are notorious for need a perfectly flat mating surface and you have added an extra two due to the decompression plate. This could well be the problem.

[sam138]

Thanks for the reply, I’ve done the heat cycle and re torque of the head. I should say that the car has been started several times and brought up to temperature with no issues until now.

The head gasket is the Af470 composite type.

[Petrol]

First of is have you done a retorque of the head after it’s first full heat cycle?? If not then check now.

Now what head gaskets have you used, copper or composite?? Copper are notorious for need a perfectly flat mating surface and you have added an extra two due to the decompression plate. This could well be the problem.

Both myself and a friend of mine have had head gasket failure on new builds.
In my case, I used a Payen copper head gasket, the head was skimmed and the block was decked
I didn't re torque the head after the first full heat cycle. Is that something I should have done?

Thanks
Pete

[sonikk4]

First of is have you done a retorque of the head after it’s first full heat cycle?? If not then check now.

Now what head gaskets have you used, copper or composite?? Copper are notorious for need a perfectly flat mating surface and you have added an extra two due to the decompression plate. This could well be the problem.

Both myself and a friend of mine have had head gasket failure on new builds.
In my case, I used a Payen copper head gasket, the head was skimmed and the block was decked
I didn't re torque the head after the first full heat cycle. Is that something I should have done?

Thanks
Pete

Recommended by an awful lot of people on here.

[Hexxeh]

 

 

First of is have you done a retorque of the head after it’s first full heat cycle?? If not then check now.

Now what head gaskets have you used, copper or composite?? Copper are notorious for need a perfectly flat mating surface and you have added an extra two due to the decompression plate. This could well be the problem.

Both myself and a friend of mine have had head gasket failure on new builds.
In my case, I used a Payen copper head gasket, the head was skimmed and the block was decked
I didn't re torque the head after the first full heat cycle. Is that something I should have done?

Thanks
Pete

Recommended by an awful lot of people on here.

 

 

I've seen this mentioned a few times - what's the reasoning behind re-torquing? I'm finding the exposed edge of my head gasket (Victor Reinz 998 composite) is perpetually wet a few weeks after fitting.

[gazza82]

I've seen this mentioned a few times - what's the reasoning behind re-torquing? I'm finding the exposed edge of my head gasket (Victor Reinz 998 composite) is perpetually wet a few weeks after fitting.

My thoughts on this are that running up to temp squashes the gasket as the block/head metal expands, so re-torquing it will close up the gaps.

[Hexxeh]

 

I've seen this mentioned a few times - what's the reasoning behind re-torquing? I'm finding the exposed edge of my head gasket (Victor Reinz 998 composite) is perpetually wet a few weeks after fitting.

My thoughts on this are that running up to temp squashes the gasket as the block/head metal expands, so re-torquing it will close up the gaps.

 

 

So literally just go around with the torque wrench again still set to the final torque and check them all? I've seen some mentions of loosening each a quarter turn first too...

[sonikk4]

 

 

I've seen this mentioned a few times - what's the reasoning behind re-torquing? I'm finding the exposed edge of my head gasket (Victor Reinz 998 composite) is perpetually wet a few weeks after fitting.

My thoughts on this are that running up to temp squashes the gasket as the block/head metal expands, so re-torquing it will close up the gaps.

 

 

So literally just go around with the torque wrench again still set to the final torque and check them all? I've seen some mentions of loosening each a quarter turn first too...

 

 

I did not back off first and re torque, just went around in sequence and check torqued at max allowed figure. In my particular case it did not work as i had a copper gasket and it still weeped. (the block deck and head face were not resurfaced although i did both for being straight and true.)

 

i ended up replacing it with a Payen HG, did one full heat cycle, checked it again and job done.

 

So by all means carry out a re torque but if it still seeps then you will need to replace the HG's i'm afraid. 

 

Please bear in mind i'm not a professional engine builder so hopefully some of the pro's like Turbo Phil ,AC Dodd or Ian 'Oz' Osborne etc can shed some light on this.

[GraemeC]

I'd always back off first - you will not get a true torque figure otherwise.  You should always come up to torque in a smooth movement, even a lubricated thread will have some stiction to it and therefore the prevailing torque will be higher than the true torque.