Replacing the head gasket

[Sidney'61]

Hi.
My engine has started having running problems, lacking in power and very jumpy at higher revs, ive noticed its using a lot of oil and theres a slight bit of yellowy gunk appeared down the side. I assume this means the head gasket has gone?

If so, how hard is it to replace? Ive done a fair bit of work on various minors so I'm not a complete beginner but I've never changed a head gasket, would it be sensible to try changing it on my own? any tips?

btw, its a 1275.

Thanks,
Andy

[simmitc]

Do you have (or can you purchase / borrow) a torque wrench and the workshop manual to show the correct sequence for loosening and tightening the bolts? As long as the answer is yes, then it's a straightforward job, just follow the steps in the manual.

You will have to disconnect the exhaust, but whether you leave the manifold in place depends on personal choice and the exact arrangement you have with the 1275 modification.

[bmcecosse]

Easy job - use a copper faced gasket and smear lightly with grease - torque to 44 ft lbf, and retorque after the first heat cycle. Well worth grinding in the valves and fitting new stem seals on the inlets when the head is off.

[stevey]

No problems, just follow the manual. Give the head and block a careful clean before it all goes back together.

[Sidney'61]

Thanks.
New gaskets ordered, torque wrench borrowed, I'll let you know how I get on

[simmitc]

One hint that isn't always in the manual: Lay out a sheet or two of clean newspaper. As you take off each nut and washer, the rocker gear, and pushrods, lay them on the paper in the correct relative positions. That way it's easy to work out what goes where when you come to refit. It would be a good idea to fit a new bypass hose (if fitted to the 1275) whilst the head is off - only a few pennies, and saves a lot of effort later.

[Sidney'61]

I finally found the time to have a go on the head gasket today.
As is always the case one part is completely stuck. It seems the middle (removal order no1) stud is seized into the head, the head is slightly loose and wiggles around the other studs yet stud 1 wiggles with it. Ive left it to soak but any better tips on removal?

[chesney]

I had a similar problem. I ended up welding a stud to the top. That didn't work, then the stud snapped, so I ended up taking the engine number tag off and 'unscrewing' the head (this engine was out of a car) then wedging it in a vice for 48 hours. Hope you have better luck than me! Don't forget a dab of oil on them for reassembly.

[JOWETTJAVELIN]

For the obstinate nut Plus-gas and much leverage will work. A ring spanner and rubber mallet work equally well.

Note the copper side of the h/g should be facing UP.

[katy]

Have you tried putting 2 nuts on the stud and "locking" them together and then try turning the stud?

[Sidney'61]

The 2 nuts method worked and i eventually got the head free, thanks Katy,
The old gasket seemed to be in reasonable condition but the engine is running a lot smoother with the new one so hopefully its fixed my problems

[bmcecosse]

Retorqued (44 ft lbf) after the first heat cycle??? And then set the gaps 12 thou inlets and 15 thou exhausts.

[Sidney'61]

Yes, retorqued and gaps set, thanks.