Cylinder Head

[jedgarrett]

Well where to start? Head gasket has gone again.havn't taken the head off yet so not sure what the state underneath is.The engine has been fine for many months being used locally but after about an hours motorway driving,noise,loss of power.Look under the bonnett and bubbles coming from between the head and block!! Pretty miffed and unsure as to why it should go again,the head was checked and confirmed as in good order prior to the latest gasket being fitted.What checks should I be making befor the next gasket is fitted?

[bmcecosse]

Bubbles from between head and block - don't necessarily mean the gasket is blown! Was it retorqued after the last fitting - after the first heat cycle? You should run a compression test and come back with the result - but first check/set the valve gaps - 15 thou exhausts and 12 thou inlets - after retorquing the head (44 ft lbf) if that wasn't done before.

[jedgarrett]

Hi and thanks,yes all was re-torqued on two occasions and found to be ok,maybe I hadn't ran it for long enough.On getting the car home I checked the state of the stud nuts and a few did require tightening! I ran the engine and a fare bit of smoke is being exhausted.I will check the tappets etc soonest,thanks again.

[bmcecosse]

Compression check is the way forward. If it was torqued - how can some 'studs' need tightening?

[les]

I'm reading that as ---stud nuts. (head nuts)

[bmcecosse]

Oh right - I see - stud nuts....

[jedgarrett]

Well cylinder head was off today,gap was found in the gasket in exactly the same place as the last one![quote][/quote]
I also found that the pipe into the top of the distributer was hanging off and that studs No's 2 and 6 were loose!!
All is back together now and sounds/looks ok.I havn't done a compression test as I havn't got a guage yet (will get one this weekend)
How long should I run the engine before checking the torques of the cylinder head? [frame][/frame]

[MarkyB]

After a heat cycle or two should do it.

[bmcecosse]

Oh dear yes - that IS rather blown.... hope you didn't run it for more than a couple of minutes like that. Torque to 44 ft lbf after the first heat cycle. Then reset the valve gaps.

[jedgarrett]

Pulled over straight away,next probably obvious question but should i wait for the engine to cool after the heat cycle and then check the torque and tappets?

[bmcecosse]

Cool yes - but not necessarily completely cold.

[jedgarrett]

All now seems to be ok,head has now had two checks after heat cycles with ajustment after first cycle only.Due to past problems I think we will give it one more check after 100 miles or so,fit a new rocker cover gasket and hopefully all will be well.Thanks to all for advice.

[bmcecosse]

I would leave well alone....