International Lancia Forums

Hi all,

Ever since I've had my S2 1600 engine, the plug of cylinder 2 didn't fit well. I presumed a previous owner had somehow tried to fit a misaligned plug... I tried not to touch it too much, but this afternoon the plug blew out of the engine. All the thread, also the aluminium, was on the plug and a clean, cylindrical hole left in the engine. Had to limp home on 3 cylinders.

So what now?

Helicoil or threaded sleeve? Can this be done without taking off the head? How much material is left for making new thread?

Any advise appreciated.

Bart

I consider a helicoil a thing to be used when travelling and you need a quick repair. There are special sleeves to repair bad plug holes. The head has to come off I am afraid.

You could look at something like "bigsert" the big brother of "timesert" but as Huib says you will need to take the head off due to swarf from cutting the oversize thread for the insert.

Tim

Understand that 1600 had 12mm and smaller engined Fulvias had 14mm spark plug threads - this mainly to allow for larger inlet and exhaust valves - 38 Inlet / 34 Ex being common.

Have seen 1600 with 14mm plugs and no problems with std valves though - so you could go that route.

I have (with difficulty) bought a midlock repair set, consisting of 4 insert sleeves with M12x1,25 on the inside and M13x1,25 on the outside, and one tap M13x1,25. It also had a piece of wax. Now the procedure is to wax the tap thoroughly and to tap with only one turn at a time. Remove the tap after each turn and all the metal is embedded in the wax, nothing inside the engine. Then clean and fit the sleeve with lock-tite; e voila, finished. It took half a day to find a supplier of this size of sleeve, and another ten minutes to affect the repair.

Bart

Wow so you got her running OK?

Does your supplier offer 14mm to 12 mm conversion?

Cheers

are you happy with the results ? Is it a long term solution ?