Mi16 Head Gasket Question

[SweetBadger 91]

Finishing off a rebuild of my aged mi16 today - all going well, came to torquing up the head bolts, and one of the last ones pulled the thread out of the block :-(.

 

Amazingly found a machine shop that was open today, and will have the block back to me with a threaded insert in place of the knackered thread, result!

 

However I don't have a spare head gasket, and I torqued up most of the bolts to 20nm plus 200 degrees before the thread went.

 

Guessing this will have compressed the gasket, meaning it can't be reused?

 

Gasket was in place for no more than 10 mins - can it still be used incase I can't get hold of another one this weekend?

 

Here's hoping that I don't get the same happen with any of the other threads...

Edited April 18, 2014 by SweetBadger

[Anthony 1,000]

I would say that it would probably be fine... but, for the sake of £15 and a couple of days extra wait is it really worth the risk?

[petert 549]

Is that the same engine you had the Cometic gasket on?

[DamirGTI 323]

OE head bolt tightening method is insane ! .. i stopped using it for quite a while now , i'd say you'll have to be lucky not to strip the threads using OE method nowadays when this engines are pretty old thus the block threads are barely able to withstand such torque force .

 

Try this method next time , works really good for me no problems what so ever since i've started using (an reputable UK race engine builder recommended me this method instead the OE one) :

 

1 - 30Nm

2 - 55Nm

3 - Loosen 1/8 of a turn and re-tighten back to 55Nm

4 - 80Nm

5 - 95Nm

 

 

D

[SweetBadger 91]

Hi guys thanks for the quick replies.

 

Managed to get hold of a new head gasket yesterday and the head is now on using the torque settings as recommended by Damir - all torqued up with no drama (although it was bloody nerve-racking doing the bolts up!). Got the engine in the car and turning over today, compression sounds very healthy on the starter, so fingers crossed it should be fine.

 

The block I'm using has had quite a number of head removals / refitting using the 20nm + 300 deg method, so I guess the threads are probably not up to being put through that ordeal again! First time I've ever had one go though, in probably 10+ times of bolting a head down.

 

Anthony, I agree normally for the sake of a couple of days and £20, it would not be worth the risk, but I'm working to very short timescales; car is currently residing 200 miles away from where I live, and I'm hoping to get it mot'd on Tuesday before I head back.

 

Peter, no, well not quite; am using the head, and pistons from that engine in this build. The engine running the cometic gasket started to get uneven on compression (3x low cylinders), and then I'm afraid to say the head gasket did eventually go on a track day. Went between cyl1 and a waterway. Lasted approx 30k miles and several track days before it went, so bearing in mind that when I fitted it I just took the head off, cleaned it up and refitted it with the cometic gasket, I got value out of it.

 

The new engine has had the block and liners decked 0.4 mm by gardias engine services (highly recommended - did a great job on the block and head too), so will be running a standard gasket.

 

Would recommend that anyone considering using a cometic gasket on a wet liner xu engine gets the head refinished with the correct surface finish for a mls gasket, and makes sure liner protrusion is spot on.

Edited April 20, 2014 by SweetBadger