mg tf 160 bad head gasket

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
 
 
 

Thats serious car jacking

Before we leap to conclusions and pour miracle muck like head gasket sealer in, the snotty residue found under your filler cap may well be hidden residue from inside the engine left over from the previous head gasket failure, It can be difficult to get all of it out. It nay boil off over time.

Hmm, true, I haven't run the engine long at all. I'll drive it around a little and hope it boils off. It would be great if it were just that. 

will keep you updated 

Keep a lose eye on your oil and panic if it starts going to snot!

I have to confess I haven’t followed your trials & tribulations, so my comments here are for general consumption & not necessarily aimed at your snot problem.
Emulsion can form with too many short runs in a moisture laden atmosphere, this could be misconstrued as HGF, creating panic. It might simply be condensate & a few good hot runs would boil that off, sometimes I’ve looked at engine oil which has had misty appearance, after a right rollicking run it’s returned to that clear golden & more encouraging look.
M

Ive heard others have found theres still emulsion snot in the oil after a head gasket change and only got rid of it by draining once again, using flushing oil and then doing another oil and filter change.

You guys were spot on! In the first few days of proper driving, it has recovered from its flu No more white foam, and it looks to be behaving nicely for now!! Now that I have a little more faith in the engine, I'm going to give it some TLC, such as fixing the electric windows, respraying the front bumper, and maybe replacing the folding roof fabric.

Thanks again for all the tips, guys!!!
It has been a super fun adventure

Thank you for reporting back & I’m pleased that you didn’t require further surgery.
We cover every permutation & so by the laws of averaged we get stuff right sometimes (it’s much much better than that) especially if Cobber is on the case.
Keep in touch with your progress.
M

Good to hear the snot has boiled off!