mg tf 160 bad head gasket

Thanks!!! haven't removed the liners yet but I did rotate the crank to get access to the piston bolts as I was planning to remove them to clean the water channels a little (They seem to be a little seized and I think the previous owner used some head gasket sealant which is gluing them a little).

Do not even remotely try to weld up that piston!
I will leeave it at that.😉

wrote:

Do not even remotely try to weld up that piston!
I will leeave it at that.😉
 

I agree totally, DON'T attempt to weld up the piston!

Top marks for wanting to have a go but id add my voice to the others, best replace rather than try to repair that piston. Piston repair should only be attempted within a very advanced engineering workshop where they can check and replicate the exact metallurgy and join seamlessly to avoid creating a stress point. It's really only ever worth it if the type of piston is otherwise entirely unavailable.

No, that's a bad idea! I've seen videos of poorly equipped workshops doing remarkable work, that though is a matter of "needs must if the devil drives". I'm of the opinion, as with the rest of the lads, that your missing piece was missing before the head was put back on. If it had broken whilst running (Why/how) it would have left evidence of its departure. Order spares & rebuild.
M

I'm pretty sure that the 160 pistons were specially hardened to cope with the increased power. This could be a rogue. 
In any case, they have 160 stamped into them on the piston top face.


Edit:- Scrub that, I think I can see 160 on your piston... 
 

Mexiiiii wrote:

Finally got around to removing the piston and can properly see the the damage, was actually pretty straight forward

 . Struggling a bit to get the liners out so I'm soaking them in penetrating fluid. 
It's got the number "135" stamped in the side. Could this be a piston from a 135 engine?(or are they the same and it doesn't matter?

 

 

 

David Aiketgate wrote:-
For some reason the 160 pistons do have 135 on the side. But as above, have 160 on the face.

 

This is of course the story of my life........Pissed n broke! 🤣
I'm sure many of you have been in the same boat!

Thanks a bunch, you awesome folks! This is my first time using a forum, and I’ve never been so happy to be told how close I came to screwing things up. You’ve all been a huge help! 
I'm going to make an order from the UK once I've gotten my shopping list finished then it's hopefully just a few days of assembling. I'll post a video of it once it's all back together (if it runs ;P)

Hi Mexiii
You seem pretty capable of getting this thing running again but I will offer a few tips if you have no written guidance.

Replace that piston and replace the rings on all of the pistons. Check the ring gaps once installed, there will be info in the ring pack. Don't assume they are "factory" gapped.
For instance ...info can say for Road use 15thou...or for Race use 40thou...you need to check the gap so they don't expand too much and nip in the bore and break. The compression ring is the important one.
Spin the rings around so that the gaps are about a third of the circumference away from each other.
Once the pistons are ready to be fitted in to the bores deglaze the bores with 400grit wet dry lightly to remove the varnish and allow the new rings to bed in.
Smother the rings with assembly grease..many types on Ebay...and carefully fit in to the bores with the pistons facing the right way. 

Replace the Big end bearing shells.

Clean the surfaces in the conrod and the cap and press in the new shells on to a clean conrod surface. Do Not use assembly grease on the back of the shells..it will effect the torque of the con rod and cap.
Once the shells are in place then lightly grease the bearing surface and the crank journals with assembly grease. Do not use grease on the conrod and cap mating surfaces where they are bolted together.
Refer to the MG manual for the correct torque settings for the bearing caps.
For instance with forged Eagle rods they give you 3 different torques setting for using the bolts dry..with oil..or with assembly grease. I am fairly sure MG will say lightly oil the bolts and give you a torque figure. CHECK.
Cleanliness is your friend when assembling an engine. It will smoke from the assembly grease on start up but will burn off quickly.

If you refurbish the head be sure to use assembly grease on the camshaft bearing surfaces!
I am pretty confident you will end up with a nicely running engine.
Good luck!
 

Thats excellent advice.

So took my sweet time to get everything sorted. Good news and bad news  . First good news: It flippen runs!!!! (Will attach a video below) So I'm pretty chuffed with that.
Bad news: there was a bit of white foam under the oil cap and on the dipstick  ( don't think that can happen due to a bad oil cooler or?), and I have a theory. As I was excitedly assembling the headgasket and cylinder head, some oil dropped onto the gasket, so I took it off and wiped it with a clean cloth to remove the oil. However, in my excitement to try to get it done that evening, I wasn't extremely thorough in my cleaning, and I think it might have compromised the seal.

So, currently, the plan is to see if I can sort out the rough idling that existed before the rebuild (think it's a faulty lambda/O2 sensor), and I'm very tempted to try a headgasket sealer until I can get my hands on another headgasket+bolts when family comes to visit (3 months)

But it turned on after the first crank, so I can't be too mad, and after some initial discouragement after seeing the white foam of despair, I'm going to give it another shot

Google Drive video links:
(The angle from the rear of the car was to see if white smoke started coming out, which did happen lightly after the video ended.) The engine also moved a lot in one of the videos, as I hadn't attached the lower engine mount yet.
https://drive.google.com/file/d/1b93MGogUE6DmWne69drLVdW1HQt_mBfh/view?usp=sharing
https://drive.google.com/file/d/1b7nnMlsKFqnFlY6w00pxQC5Ye93eg7SS/view?usp=sharing


The MacGyver way of getting the seized piston liners out using the broken piston and old piston ring for an mg tf. Put the piston in the liner in reverse till the ring expands at the bottom, and use a car jack to pull it out with the liner