Cylinder head removal
Discussion
Finally got the second cylinder head off the engine. The reason for being stuck was corrosion around one of the head studs. Some things I've learnt that may be of help to others. The aluminium is pretty soft and I've damaged a couple of the edges of the exhaust ports by using a copper mallet to get things moving. Small chisels/scrapers at the corners where there isn't a sealing surface can help, its hard to resist the temptation to hit it hard.
I had a couple of strips of steel that I drilled and bolted in place of the inlet and exhaust ports. These enabled the engine to be suspended from the engine hoist with the weight of the block acting against the head. This didn't really do much, even after 4 weeks of tapping and WD40.
The thing that finally worked was welding some bits of scrap metal with a M12 hole tapped directly above one of the main studs. This enabled a direct upward force which finally go things moving. I also used small angle pieces of steel (bolted to the front cover holes) with a threaded bar between them to push that end of the head apart from the block.
This shows the general state of affairs with the ground clamp from the welder near the oil/water pump.
This is the collection of steel that finally worked, I also had to use the plug in the rear of the head to stop the metal bending. Its a 3/8" square hole, hence using a ratchet to hold it in place.....
If I had to do it again I'd skip a lot of the earlier steps and go straight to some way of using a screw thread to press the head off.
I had a couple of strips of steel that I drilled and bolted in place of the inlet and exhaust ports. These enabled the engine to be suspended from the engine hoist with the weight of the block acting against the head. This didn't really do much, even after 4 weeks of tapping and WD40.
The thing that finally worked was welding some bits of scrap metal with a M12 hole tapped directly above one of the main studs. This enabled a direct upward force which finally go things moving. I also used small angle pieces of steel (bolted to the front cover holes) with a threaded bar between them to push that end of the head apart from the block.
This shows the general state of affairs with the ground clamp from the welder near the oil/water pump.
This is the collection of steel that finally worked, I also had to use the plug in the rear of the head to stop the metal bending. Its a 3/8" square hole, hence using a ratchet to hold it in place.....
If I had to do it again I'd skip a lot of the earlier steps and go straight to some way of using a screw thread to press the head off.
The Triumph Stag community are experts at removing corroded head studs & bolts and they've come up with a few great techniques.
1 - The Rope Trick
Remove as many of the head bolts/studs as possible.
Take all of the spark plugs out if they are not out already.
Shove ~3ft of soft rope into the cylinder with the piston at the bottom (leave the tail of the rope out)
Slowly turn over the engine - you can use the starter motor if you're careful.
Remove the rope and put it in a different cylinder and repeat until the head budges.
2 - Hydraulics
Use the other head to push against to remove the stuck head...or in the Stag's case, once you remove one stuck head, put some bolts back in and push the other stuck head off.
3 - Ultra sonic
The special tools needed apart from the usual spanners etc. are :- a compressor , air chisel and a riveting head for the chisel.
You lock the bolt with two nuts leaving the top 6 or 7 mm of stud exposed (say the top 2 threads plus the slotted bit ) . Then you apply the air chisel to vibrate the bolt . With your spanners on the lock nuts you GENTLY try to undo it . IF it's tight - vibrate some more - if it's lose then undo it , sometimes applying a bit more vibration if it goes tight again .
1 - The Rope Trick
Remove as many of the head bolts/studs as possible.
Take all of the spark plugs out if they are not out already.
Shove ~3ft of soft rope into the cylinder with the piston at the bottom (leave the tail of the rope out)
Slowly turn over the engine - you can use the starter motor if you're careful.
Remove the rope and put it in a different cylinder and repeat until the head budges.
2 - Hydraulics
Use the other head to push against to remove the stuck head...or in the Stag's case, once you remove one stuck head, put some bolts back in and push the other stuck head off.
3 - Ultra sonic
The special tools needed apart from the usual spanners etc. are :- a compressor , air chisel and a riveting head for the chisel.
You lock the bolt with two nuts leaving the top 6 or 7 mm of stud exposed (say the top 2 threads plus the slotted bit ) . Then you apply the air chisel to vibrate the bolt . With your spanners on the lock nuts you GENTLY try to undo it . IF it's tight - vibrate some more - if it's lose then undo it , sometimes applying a bit more vibration if it goes tight again .
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