Removing cylinder head bolts

[AndyB57]

The 4 bolts on the front cylinder head are proving very reluctant to loosen. I've used Plus Gas and heat numerous times but none of them are showing any inclination to undo and I feel I'm in danger of breaking something if I lean on them much more. Is the only answer to keep using the Plus Gas, heat and a longer wrench??

[huub]

remove the allan screw in the pushrod tunnel

[AndyB57]

remove the allan screw in the pushrod tunnel

Thanks but I'm not at that stage yet.

[trinder]

Try tighten, then loosen, old Fuzz Townsend top tip from Car SOS.

[Steve Brown]

Try tighten, then loosen, old Fuzz Townsend top tip from Car SOS.

This plus what Huub said. Loosen that M6 cap head first. Not that it loosens the main stud/nut set but it means less torque required to get the cap head out so less likely to round the socket.
For the main 13mm nuts try to get hold of a 6 point socket, less likely to round the nuts off. You won't do much damage if you apply plenty of force to loosen them. The worst that can happen is the stud may shear. I have plenty of those spare if that happens, FOC + postage!
I would avoid using heat there as I think it would be hard to target the heat exclusively to the steel bits. They shouldn't be too hard for a decent socket and wrench to shift them.

[72degrees]

I did have one stud unwind from the cases because the nut was corroded on, but that's not too big a deal with the engine out. Possibly awkward with it still in and being unlucky which stud.

You could try 'shock 'n unlock' (freezing/penetrating spray) instead of Plusgas, though that works best with alloy/steel interfaces.

+1 on the recommendation for loosening the cap screw first than a 6 point or surface dive socket.

They are 'nyloc' nuts (well they are, and a new set each time on mine), so a fair amount of stiction if they were torqued up properly.

There eventually comes a time to fetch out the 'breaker bar' - though it may do as in says on the tin.

[AndyB57]

Thanks trinder, SB and 72degrees - too wet for gardening, etc this afternoon so going to have a proper go at them with more oomph. I'll let you know how it goes.....

[AndyB57]

Eased the bolts off! I can tell the Allen bolt could be challenging to remove with the engine in the frame though.......

[3potjohn]

The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John

[AndyB57]

The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John

Planning to have a go tomorrow, hopefully it'll all be plain sailing and I can have a look at the valves then bolt it all back up.

[Steve Brown]

The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John

Planning to have a go tomorrow, hopefully it'll all be plain sailing and I can have a look at the valves then bolt it all back up.

If you weren't already planning to do it, take the barrels off and replace the base gasket. 9 times out of ten if you remove the head then the barrel moves slightly-enough to break the seal and you'll have an oil weep to annoy you. If you are planning this, simply read back to the top and skip this message.

[72degrees]

The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John

Planning to have a go tomorrow, hopefully it'll all be plain sailing and I can have a look at the valves then bolt it all back up.

I always stuff some paper towel or rag in to the pushrod tunnel while taking the socket head screw out, and when putting it back in. You won't forget to take it out because the push rods won't drop in until you do

[AndyB57]

I always stuff some paper towel or rag in to the pushrod tunnel while taking the socket head screw out, and when putting it back in. You won't forget to take it out because the push rods won't drop in until you do [/quote]

Thanks - I took one look at those holes and then the Allen bolt, grabbed some paper towel before I did anything else!

[AndyB57]

Excuse my ignorance, but having looked at various drawings I cannot for the life of me work out what the Allen bolt does! The pushrods on my engine can be removed with it in situ - does that mean something is missing if the bolt is supposed to secure them in some way?

[72degrees]

Excuse my ignorance, but having looked at various drawings I cannot for the life of me work out what the Allen bolt does! The pushrods on my engine can be removed with it in situ - does that mean something is missing if the bolt is supposed to secure them in some way?

Helps seal the head gasket round the push rod tunnel. You can remove the pushrods, but you won't be able to lift the head until the cap screw is out.