Just about had it !
Turbo Mini Forums

My newly built engine blew its head gasket between piston 2-3, after doing 750 miles to wear the engine in on back roads using the rev range and slowly increasing it as I built up the miles, I booked it in to get the timing set up and advised the garage of the engine spec and miles it had done, once getting it back I drove it for a few miles ( didn't run great al low revs ) then at 12psi it back fired at approx 4.5k and then it was missing. Upon inspection as I said it blew between 2-3, at the time I was very angry at myself as I had not re checked the torque on the head bolts after 500 miles.

So what next, well today I installed a brand new BK450 head gasket Having looked at the advise from here, even though the one that blew was a BK 450, I also tapped in to the inlet manifold to get an accurate boost reading. I torqued the head down to 55nm With a wrench that I had checked today to ensure it was right, took her down the road and all was great , upped boost to 10 psi and at 4k she blew water out of my rad cap and loads of fumes out of the breather . Once I managed to push her home ( fortunately not far) I checked the compression and now number 4 is down to 90psi so I am back to square one .

I have a replacement gasket but it's an all copper coloured one, from previous experience with these ones on turbo engines I have had no issues what so ever but since using the BK 450 I have had nothing but troubles, I know everyone on here uses the BK450 but am to be honest a bit disappointed. I have checked the fueling and timing all is spot on. Not sure if anyone else has suffered the same issue ?

Any advise chaps ??

I doubt the head gasket is the issue here. How do you know the fuelling is spot on ? What's the timing set to ? What's your compression ratio ?

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Yes this well common... sadley!

The torque settings are 55 ft pound not Newton meters,

What compression ratio are you running and the spec of your engine. Ie piston dish CC and head chamber CC. ?
This is caused by detonation preignition. ....are you running an intercooler also?

Was you running low grade fuel 95 ron? On 99 ron....... Dont despaired! Take a step back and lets have a look

Is this on a dizzy?
Dont be discouraged either mate we have all had this at some point there is only a limited number of reasons it happens , its a case of checking through them step by step

Edited by Brett on 15th Aug, 2012.

Yes i moved to the darkside

Instagram @jdm_brett

Thanks for the advise, it's one of your engines Steve, I bought it from benyaris a while back, he had bought it from you for a project but he gave up and sold the engine off. I have the fuel pressure set at 3.5 psi on idle and approx 4-5 psi above the boost . One thing I don't have is an ecu , it's still on dissey

Sorry to add ( my computer just crashed) its electronic Dissey , the co2 is 3.7 on the local garage machine which I am told if anything is slightly too rich .

Oh and yes it's running Ron 95 fuel, should it be 97 , was worried this may be too much for her ?

You need to get it setup before you break something.

What ignition advance are you using at that boost? What CR.

You should definitely be using the best fuel you can lay your hands on and be taking in very easy until you either get it to a rolling road or buy yourself a wideband. That CO2 reading is useless.

In the 13's at last!.. Just

Also, retourqing the head wouldn't have cured your first failure.

In the 13's at last!.. Just

There are a few points that need looking at that have been mentioned. Also check the head is flat you take it off. I would not let an engine see boost without a rolling road setup to be honnest.

If it the compleate engine and box I. Remember
The compression is 8.5:1

Right you can go around upping the boost with no intercooler running crap octain fuel on a standard distributor with a unknown mixture? And expect to do mass of amountnof HP and be reliable, sadley this is a classic case!

You need a AEM LAMBDA wide band fuel gauge and megajolt set correctley with a safe map in or at least a modded Turbo dizzy with Max advance of 24 degrees. ..... but the magajolt is the best option!

Then you need to go to a rolling road with a knowledgeable. Operator on the above and set the engine correctley!! Say 16 pounds of boost with an intercooler and thats then ok if the fueling is between 11.5 And 12.5 to1 ratio and the maximum advance Dont exceed 24 degrees

Yeah good point, does anyone know of a suggested rolling road anywhere near Devon ?

Do you have a picture of the failed gasket. It will help diagnose the cause of the failure.

Double check what you are torquing it up to, as Steve says, its 55lbft or 68NM.

As above retorqung will do nothing.

btw, I use a copper AF460 on my hillclimber with no issues, the BK450 is considered better though.

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

Also Dont run the car anymore untilled you have accomplished the above or it could be a piston melt down next time. Sorry to be point blank but you have a very good engine there and I would be a great shame if It ended in total. Tears for you wiith out addressing the above points ASAP!!!!!

Also Dont run the car anymore untilled you have accomplished the above or it could be a piston melt down next time. Sorry to be point blank but you have a very good engine there and I would be a great shame if It ended in total. Tears for you wiith out addressing the above points ASAP!!!!!

Thanks Steve, I have an intercooler on it so will get a new gasket on and get all the points above addressed .

Cheers

With The wide band gauge it looks like it bolts in to the exhaust ? Is this right , if so I need to get my down pipe changed . Also are these any good ?
http://www.ebay.co.uk/itm/AEM-Wideband-AFR...#ht_1780wt_1064

http://www.ebay.co.uk/itm/Complete-Megajol...7#ht_873wt_1002

Cheers

With The wide band gauge it looks like it bolts in to the exhaust ? Is this right , if so I need to get my down pipe changed . Also are these any good ?
http://www.ebay.co.uk/itm/AEM-Wideband-AFR...#ht_1780wt_1064

http://www.ebay.co.uk/itm/Complete-Megajol...7#ht_873wt_1002

Cheers

Chin up fella, I have broken a nearly new gt20 after 100miles, I wish it would have been a £12 gasket

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Might be worth checking the triggerwheels website for MJ, if you know anything about wiring, or can get edis parts cheaper or whatever, then it may work out cheaper.

aem wideband is the same as mine; you will need to weld the boss into the downpipe but you should be able to use your existing pipe

Have others fitted the lambda boss to the down pipe with the downpipe fitted to the car?

Yes! That's the wideband AEM. And the megajolt set up, but...... you can get. Most of the parts from the scrap yards for 20 pounds Max! Don't get pillocked offer 20 pounds Max for the Edis until the one without the vacume take off and the coil pack and leads also crank sensor

A list of of UK cars are available on the trigerwheels.com. website......... where you. Can obtained. The parts .... saves you pounds.

Crank trigger wheel and EDIS MAP you can buy from trigerwheels.com. or. .... preferred. Tom fenton our very own hero! And fentonator! Could supply the bracket and machined. Pulley...... if Tom still does these. ?

Please get up to speed on the trigerwheles website while you are waiting for your parts.

I hope all the above, what peeps and me are saying will place you in to a more educated position when you have swatted well

After that we are all here to help for any problems

Dazed and Confused....