Blown head gasket

Post by **millerman** » Tue Oct 18, 2005 11:26 pm

I have had a 70thou head skim and this head is fitted to a 1098cc engine with 20thou oversize bores. New copper head gasket fitted in july this year , 1800 miles ago, Payen I think. Head was retorqued to correct figure 100 miles after fitting. I usually aim to keep up with traffic at 65 - 70mph.

Anyway gasket blew between 3 and 4 cylinders today.

Advice required on how I can get the head gasket to last longer, torquing after 1000 miles,I suspect, would have helped. Are there any heavier duty gaskets that will maybe give better service?

Cheers

Post by **Cam** » Wed Oct 19, 2005 12:05 am

You can get a copper 'competition' type head gasket from most mini specialists (they also use the 1098 engine). I always torque the head first, then run up to working temperature then torque the head again when cooled down. Then re-torque again after 500 miles (first oil change).

Although if everything is OK a standard head gasket should not blow! Are you sure the head and block faces are true?

Post by **bmcecosse** » Wed Oct 19, 2005 10:32 pm

Not much in the way of competition gaskets for 998 engine these days - it's all for the 1275. But he says 'copper' gasket anyway. Maybe just bad luck - or maybe the head deck is now too thin and has warped or cracked - but at 70 thou it should have been ok. Only way to find out is to strip it and see what's up. My car blew the gasket 6 years ago - I had to change it at the side of the road with just ring spanners (walked a mile to get gasket from Autoparts and mile back again - and ever since carry a spare with me) and that gasket is still fine after 12000 miles of hard driving. So don't give up on it yet !

Post by **Alec** » Thu Oct 20, 2005 7:04 am

Hello Millerman,

if the head has recently been skimmed, then it should not be bowed, so I would suspect a crack in the head.

Alec

Post by **millerman** » Thu Oct 20, 2005 5:58 pm

Thanks for comments.
Head has been put back with a new gasket. I will torque down again tomorrow and I haven't given up on it yet . Alec, there didn't appear to be a crack, althou' job was done before I read your post.
I'll keep you informed if there are any more problems.

Post by **Alec** » Thu Oct 20, 2005 6:01 pm

Hello Millerman,

fingers crossed, but cracks can be quite indistinct and sometimes need careful scrutiny to detect.

Alec

Post by **bmcecosse** » Thu Oct 20, 2005 8:36 pm

Did you run the car any distance with the blown gasket ? And did you try a straight edge across the block and/or the head ?

Post by **millerman** » Thu Oct 20, 2005 10:15 pm

I did check the head with a straight edge and that seemed ok. ran car approx 1/2 mile with a blown gasket and I haven't checked top of block. Fingers crossed at present!

Cheers

Post by **bmcecosse** » Fri Oct 21, 2005 9:53 pm

Should be ok - think positive !

Post by **Peetee** » Sat Oct 22, 2005 6:24 am

but cracks can be quite indistinct and sometimes need careful scrutiny to detect

Yes indeedy. I spent hours in my shed last winter porting and flowing a head only to find the thing was cracked in two places. Without the clean up they wouldn't have been visible and probably not been a problem!

Post by **bmcecosse** » Sat Oct 22, 2005 9:59 pm

Which is why the 12g940 head is such a good idea. Dead cheap on ebay - and comes ready ported and flowed all you could really want for 948/1098 engine. Of course if it's a 1275 engine it can be further improved - but it's fine just as it is for the smaller engines.