Mini turbo head gasket problems!
Turbo Mini Forums

Hi all! very new to all of this.
Just got my mini turbo all pretty much built up, ( OR my boss did anyway )
Took it out for its first run and it blew the head gasket straight away when it got full throttled!
Was running very well before hand and seemed very fast too!
Not very mechanically minded myself as im a painter, but wondered if anyone may know what may have caused this? The head has been removed since and my boss does suspect it may not be a turbo head.

Something doesnt seem right as the gasket actually blew out the side of the engine and sounded like it was only running on three plugs!

Also anyone know what the best head gasket would be to get for it?

Thanks Dan

the std BK450 gasket is fine, there were a few duff ones flating about a couple of years ago, but the current ones are good.

you need to be sure that the gasket going is not symtomatic of another problem, ie poor fueling or timing, or too much boost,

Also worth checking out what you compression ratio is while the head is off.

Until youve had it on a rolling droad to check the fueling and timing you dont want to be abusing it though as its easy to wipe the pistons out with a lean mixture.

ahh i see. Sorry if i sound stupid but how would i check the compression ratio? I know my boss has not fitted the boost guage yet so that is a concern of mine incase it was just boosting far too much.

Failures of the head gasket out of the side of the head are generally caused by a head incorrectly torqued down (too low) or something isn't flat.

Check your torque wrench.

Some photos of the gasket would be useful to help work out the cause.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

get hold of a syringe, stick somthing like an old CD on the head sealing it on with a smear of grease or vasaline, fill with liquid noting how much youve put in, you should be able to tell with in a cc how much the chamber holds,

do the same for the block at TDC which can be tricky as anthing thin can leak past the rings,
once you have the figures the compression ratio can be calculated,

Even if you dont have a turbo head it shouldnt be an issue, as the combustion chambers are the same size across all the heads unless its been skimmed at some point,

on any turbo car I'd always fit a wideband lambda gauge, they can be picked up for about 150quid new and then you'll always know what the fueling is doing, also well worth getting a boost gauge in there.

good call on the head torque too.

yea thats what we thought, but the head seemed to be fitted correctly.

Trouble was i bought the engine already built, but i dont think the part number on the gasket was bk450 so may have been a weaker gasket too.

Will hopefully get some pictures on monday to post on here.

Anyone know where i may be able to get hold of a bk450 gasket as soon as possible? Live in the Lincolnshire area but will

its the std metro gasket, so any motor factors should suffice,

Motor factors, ask for a BK450 or an AF470.

It's rarely a head gasket problem. Yes yes BK450 is the most robust, but the failure you have will not be solved by using one.

Unless you checked the head torque, you have no idea if it was correct or not really.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

ahh right i see. sure my boss checked the torque settings but will have to check. Will get it on a rolling asap after its back on the road again. Will come back to you when i know more! Thanks For the info

It's not an uncommon problem for torque wrenches to be inaccurate. I went through many head gaskets before I worked out mine was 10lbs out.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

What boost are you running? Is you ignition timing correct? And your fueling? Are you using an intercooler? Whats the spec of your engine Turbo etc? ? Questions I know but they need answering

Failure. To know where your are with the above will quickley bring in detonation.... resulting in your failure and constant failures,

no amount of head gaskets or pistons will last till you sort the above questions out and get advise. From us to correct issues
hope this helps

Also as the gents above state

Edited by BENROSS on 23rd Sep, 2012.

Well as my boss hasn't fitted the boost guage I am unsure on that. Think when it gets up and running again I will need to take it on a rolling road and make the sure the fuelling and timing etc is all set up correctly to make sure it doesn't happen again.

Think my boss is fitting a different turbo head as he thinks mine may be at fault, but I'm still not convinced, obviously I don't know much myself as I'm still learning but I just don't want the problem to re occur.

Whether it is or isn't a turbo head will make no differance. The only differance between the turbo and no-turbo head is the exhaust valves. The turbo has sodium filled valves, but these are unnesessary.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Hi there just a quick update. Had the head fitted again which was a turbo head, thought the head was originally not tightened down right so had it all rebuilt and was running it for about a week and the head gasket has gone again but now in a different place. Boost gauge has been fitted and seems to be running at a max boost of about 7 psi and that was with the engine revving quite high. Have been suggested it might be high compression and that 2 head gaskets might solve this? Anyone have any other ideas what might be causing it?

Try reading some of the posts already in this thread..