Technical Rocker cover

[Highland jamck]

Hi, I was treated to a spray of oil over the top of the engine the other day and was looking at a 10 yo thread which I’m sure remains relevant. However, before ordering a gasket, looking in hoses or contemplating something more serious, I did find the rocker cover was VERY loosely bolted. I know one mustn’t over- tighten, but how tight is too tight I wonder? One bolt was able to turn about a whole turn with no resistance at all to a socket, and it feels like the issue could be that simple. So, in essence, how far should I go …. Any simple terms guidance?!

 

[bugsymike]

Hi, I was treated to a spray of oil over the top of the engine the other day and was looking at a 10 yo thread which I’m sure remains relevant. However, before ordering a gasket, looking in hoses or contemplating something more serious, I did find the rocker cover was VERY loosely bolted. I know one mustn’t over- tighten, but how tight is too tight I wonder? One bolt was able to turn about a whole turn with no resistance at all to a socket, and it feels like the issue could be that simple. So, in essence, how far should I go …. Any simple terms guidance?!

Generally I would say with most rocker covers, nip it up to close contact then about half a turn more with a new gasket, then run for a little will then check and if needed nip it up a little more.
Over tightening just distorts the metal cover and causes more problems.

 

[Highland jamck]

Generally I would say with most rocker covers, nip it up to close contact then about half a turn more with a new gasket, then run for a little will then check and if needed nip it up a little more.
Over tightening just distorts the metal cover and causes more problems.

Thanks. I’m going to try it at that, which I think is about what I’ve done, and remain hopeful

 

[the hobbler]

Thanks. I’m going to try it at that, which I think is about what I’ve done, and remain hopeful

You say that one BOLT went up a turn without resistance---do you mean a NUT, or, was the stud that holds the rocker cover in place loose? I ask because the stud that holds the rocker-cover in place also retains the rocker-shaft. On early 500s, it was not unknown for those studs to come loose, which will affect the valve settings and general running of the engine. I have come too this problem a number of times. If the stud IS loose, check the thread in the head for damage---if it is damaged, you will need to repair it. One method for that repair (and I have used it successfully every time) is to use a "self-tapping steel insert" as sold by "MEMFAST".These are almost identical to the inserts that used to be recommended(and supplied) by Abarth. You will have to think a bit as to what washers you use to make the insert fit flush, but that is not a difficult problem.
If the stud has stayed tight, I would suggest that you fit a"rubberoid" gasket and NOT the cork version. Before you refit the rocker-cover, check that it hasn't been "bowed in"---if it has, try to knock the bow out as the little strengthening braces inside the rocker-cover might make contact with the rockers.When refitting the rocker cover,there should be a flat washer and a fibre washer under the securing nut--a 'ny-loc' nut. As "bugsymike" has suggested, tighten the nut until there is "close contact", and then nip it up another 1/2 turn

 

[Highland jamck]

You say that one BOLT went up a turn without resistance---do you mean a NUT, or, was the stud that holds the rocker cover in place loose? I ask because the stud that holds the rocker-cover in place also retains the rocker-shaft. On early 500s, it was not unknown for those studs to come loose, which will affect the valve settings and general running of the engine. I have come too this problem a number of times. If the stud IS loose, check the thread in the head for damage---if it is damaged, you will need to repair it. One method for that repair (and I have used it successfully every time) is to use a "self-tapping steel insert" as sold by "MEMFAST".These are almost identical to the inserts that used to be recommended(and supplied) by Abarth. You will have to think a bit as to what washers you use to make the insert fit flush, but that is not a difficult problem.
If the stud has stayed tight, I would suggest that you fit a"rubberoid" gasket and NOT the cork version. Before you refit the rocker-cover, check that it hasn't been "bowed in"---if it has, try to knock the bow out as the little strengthening braces inside the rocker-cover might make contact with the rockers.When refitting the rocker cover,there should be a flat washer and a fibre washer under the securing nut--a 'ny-loc' nut. As "bugsymike" has suggested, tighten the nut until there is "close contact", and then nip it up another 1/2 turn

I must apologise, I think I do just mean the nut, and I hope - haven’t tested yet - that will be all for now. I’m such an amateur ….. but grateful for all the support offered and received!

 

[bugsymike]

If the stud has stayed tight, I would suggest that you fit a"rubberoid" gasket and NOT the cork version. Before you refit the rocker-cover, check that it hasn't been "bowed in"---if it has, try to knock the bow out as the little strengthening braces inside the rocker-cover might make contact with the rockers.When refitting the rocker cover,there should be a flat washer and a fibre washer under the securing nut--a 'ny-loc' nut. As "bugsymike" has suggested, tighten the nut until there is "close contact", and then nip it up another 1/2 turn

Good point about "rubberoid" gaskets if available, much better than cork ones that compress up and deteriorate.
Manufacturers gradually moved to the rubberoid versions and some put the steel inserts in to prevent overtightening, mind you that was shortly before the went to OHC and hydraulic tappets etc.
Before that in my workshop I had a rack with the most common gaskets of the time, mostly Ford and A & B series, along with Hillman etc. To change at every full service.