Fuego Head Bolts

[alpinesau]

When tensioning the head bolts on my Fuego, they bound up, then released with a sharp crack repeatedly. Therefore it is impossible to determine the correct torque. This happened on the middle 3 bolts on the inlet side. All the others were OK. I ensured that the bolts were oiled and the threaded holes in the block were free from coolant, oil etc. (Using a pipe cleaner).
Any suggestions?
I plan to take the head off again and chase out the threads with a tap. Can I re-use the heat gasket or is that too risky?
Any advice from those who have experienced this condition previously would be most appreciated.

Robert

 

[Haakon]

Has the head ever been off before at the hands of someone else? If so, I bet they let bits of carbon fall into bolt holes in the block, and ruined the threads in the soft alloy of the block when head bolts were replaced. Nothing for it but to get the threads redone with Helicoil inserts, which means taking car on a trailer to an engineering firm (or taking out the engine!) or finding one that will come to you. Had exact same problem on my girlfriends R21 - gasket went 6 mths after some cowboys fixed it for the previous owner ( replaced gasket without bothering to reface head and clean block or head!) I am now faced with possibility of doing it all over again 6 mths on again as the threads in the block were pretty bad on 3 bolts and was impossible to get an accurate torque setting (didnt have time at the time to get threads fixed), only this time I will definately have to get the threads fixed. I am keeping a nervous eye on coolant levels, and hoping like hell a tweak of a couple of head bolts will stem what is so far small loss of coolant.

 

[Simon]

Initially I thought the Fuego head might have to be tensioned to angle rather than torque, but that isn't the case.

I'm just wondering if it is some weird metallurgical effect where the alloy is very dry and the thin oil coat on the bolt is quickly "sponged up" by the block thread.

Just wondering if filling the thread with oil, leaving it for an hour or so to absorb into the block then removing the oil would resolve the problem.

The gasket should still be OK as most seem to have a thermal adhesive which only sets when the engine is run. So if the engine hasn't been run, and the gasket isn't damaged and is correctly torqued it should be OK.

Simon

alpinesau:
When tensioning the head bolts on my Fuego, they bound up, then released with a sharp crack repeatedly. Therefore it is impossible to determine the correct torque. This happened on the middle 3 bolts on the inlet side. All the others were OK. I ensured that the bolts were oiled and the threaded holes in the block were free from coolant, oil etc. (Using a pipe cleaner).
Any suggestions?
I plan to take the head off again and chase out the threads with a tap. Can I re-use the heat gasket or is that too risky?
Any advice from those who have experienced this condition previously would be most appreciated.

Robert

 

[COL]

Hi All

Had a problem with spark plug hole threads on a R12 years ago when I was doing a rebuild. I removed the head had the threads fixed and reused the head gasket. The engine had never been started and lasted for years afterwards. So Robert get those threads fixed and put it back together and everthing should work out O.K.

Regards Col.