Cylinder head is coming off!

[Andymoor94]

Pottering around, 50 miles , all in one go or lots of short trips?

John ;-)

Split among 4/5 separate trips, but I've also had the engine running at a car meet and general tuning

[paul 300358]

Did you change the oil after you removed the head, the oil could have become contaminated with water as the head was removed.

[oliver90owner]

Is the engine ever reaching normal working temperature? If the thermostat is defective the engine will be over-cooled. If there is a lot of piston blow-by there will be a lot of moisture going to the crankcase.

Mixture too rich will mean more water produced during combustion than normal. Poor crankcase ventilation would not help matters either.

Did you re-torque the cylinder head bolts? Did you use a torque wrench when tightening down? Did you check the deck, as well ad the head, for flatness?

It is likely just short runs causing the problem if all the above have been checked out.

Checking after a long run would be good, as well as keeping a watch on the oil colour until the issue is resolved.

[Andymoor94]

Is the engine ever reaching normal working temperature? If the thermostat is defective the engine will be over-cooled. If there is a lot of piston blow-by there will be a lot of moisture going to the crankcase.

Mixture too rich will mean more water produced during combustion than normal. Poor crankcase ventilation would not help matters either.

Did you re-torque the cylinder head bolts? Did you use a torque wrench when tightening down? Did you check the deck, as well ad the head, for flatness?

It is likely just short runs causing the problem if all the above have been checked out.

Checking after a long run would be good, as well as keeping a watch on the oil colour until the issue is resolved.

Did you change the oil after you removed the head, the oil could have become contaminated with water as the head was removed.

To answer all of the above:

Did I change the oil? No, never even considered I would've OBVIOUSLY leaked water into oil passages! Oops.

Ever working temp? Yes, absolutely

Rich mixture? I've been battling with this a bit actually after installing dual carbs. Still finding the correct settings!

Poor CCV? I wouldn't have though so, nothing to suggest so

RE torquing. Yes, Absolutely did! To 45ft lbs (I believe) in the sequence as per the manual. I bought a torque wrench especially

Flatness? Checked with straight edge and feeler gauge. All appeared well

Oil colour, what should I be looking for?

Great help as always from the ever so diligent members of the forums!

[philthehill]

Mayonnaise in the rocker cover of a Minor is a common thing if the engine is not run at the correct temp.
You used to be able to get a cold air deflector to fit in front of the rocker cover to keep the top of the engine warm.
I found that certain oils were more prone than others to produce mayonnaise.
Do you have a 82 degree thermostat fitted?
It has been very cold lately so much easier to produce mayonnaise if the engine is not hot.
If you are not loosing water I would ignore the mayonnaise, get the engine up to temp and enjoy.

[Bowie69]

If short trips, quite expected I would say.

[Edward1949]

Pottering around, 50 miles , all in one go or lots of short trips?

John ;-)

Good point. Also Andy states that some water was spilled into the engine during head removal. Could be just burning this off. Hopefully will disappear after some more miles.

Edit: just realised another poster already made the point about water spillage, sorry

[Andymoor94]

Pottering around, 50 miles , all in one go or lots of short trips?

John ;-)

Good point. Also Andy states that some water was spilled into the engine during head removal. Could be just burning this off. Hopefully will disappear after some more miles.

Edit: just realised another poster already made the point about water spillage, sorry

Well I haven't ever changed the filter since buying it and only changed the oil that same week. May aswell install the restrictor I bought from Declan and a new filter, as well as drain the contaminated oil anyway. Only £11 for some 20W50 to be here on Saturday so why not

[irmscher]

Check the torque of the head bolts

[Andymoor94]

Check the torque of the head bolts

As previously said, I torqued them all, in sequence too

[oliver90owner]

Oil colour, what should I be looking for?

I think you would recognise an oil/water emulsion!

[Sleeper]

" RE torquing. Yes, Absolutely did! To 45ft lbs (I believe) in the sequence as per the manual. I bought a torque wrench especially "

Does that mean you re-torqued the head bolts after the first heat-cycle?

John ;-)

[Andymoor94]

" RE torquing. Yes, Absolutely did! To 45ft lbs (I believe) in the sequence as per the manual. I bought a torque wrench especially "

Does that mean you re-torqued the head bolts after the first heat-cycle?

John ;-)

Absolutely not damn!
Guess I'll take him out and do it now

[irmscher]

That's what I was referring to

[oliver90owner]

That's what I was referring to

See post @ Thu Apr 29, 2021 11:50 am.