Manifold Change
Discussion
Got nice new shiny stainless manifolds to fit and despite lots of soaking and all sorts of other tricks it looks like most of the old manifold bolts are going to sheer. I am thinking that as I am changing the engine mounts at the same time I might be able to jack the engine to get sufficient clearance to get an angle drill in to drill out the bolt remains. Anyone got experience of doing it this way as I really don’t want to take the heads off.
Rob.
Rob.
i got all of mine off using a set of bent spanners and buckets of release oil. i also warmed the car up and cooled it for the most stubborn one which was also the hardest to access. i considered the last bolt to be one of the 'the faint hearted' moments.
the trick is gradual application of force, definitely not 'cracking them' free.
the trick is gradual application of force, definitely not 'cracking them' free.
phillpot said:
Always handy to know someone with a spare pair of brand new old stock cylinder heads 
Very handy, but I do hope I don't need them. Had another little tweak at the bolts tonight, still no sign of movement, even split the washers off one so the head is free, still not moving. Been soaking them for a couple weeks now with releasing oil but no joy. Bit reluctant to go past the point of no return at the moment with the nice weather.Thanks for all the ideas.
Rob.
Hi Rob,
If you've got the washer split off, try tightening the nut a little to break the hold of the corrosion on the threads. Also "shock" it with a few careful hammer blows using an old socket that just fits over the stud.
Plenty of plus-gas & perseverence worked for me.
If you get the nut moving and it starts to "bind", apply more plus-gas and tighten it a little, then undo it again. Keep it moving back & forth, it should free off eventually.
If you've got the washer split off, try tightening the nut a little to break the hold of the corrosion on the threads. Also "shock" it with a few careful hammer blows using an old socket that just fits over the stud.
Plenty of plus-gas & perseverence worked for me.
If you get the nut moving and it starts to "bind", apply more plus-gas and tighten it a little, then undo it again. Keep it moving back & forth, it should free off eventually.
I presume you won't be able to get to some of them with these.
http://www.machinemart.co.uk/shop/product/details/...
They work well and don't damage the thread, it's just a matter of access.
http://www.machinemart.co.uk/shop/product/details/...
They work well and don't damage the thread, it's just a matter of access.
Barkychoc said:
I presume you won't be able to get to some of them with these.
http://www.machinemart.co.uk/shop/product/details/...
They work well and don't damage the thread, it's just a matter of access.
But they are BOLTS not NUTShttp://www.machinemart.co.uk/shop/product/details/...
They work well and don't damage the thread, it's just a matter of access.
Barkychoc said:
Ah Ok ignore me!
Not at all, they are a very useuful tool and as a last resort you could use them to cut off any bolt heads that refuse rather than snap them off. Then if you can wriggle the manifold off you will have a length of thread to which you will have better access. You may be able then to put 2 nuts on, lock them together and try to spanner the remaining thread out. If that fails, mole grips and if that fails..................well lets not go there yet.Another thing to try is heat. A good hot blow torch on the bolts but be CAREFUL, you dont want a bonfire. When its cooling down some more penetrating oil and repeat.
They will come out but you just need patience and avoid brute force.
When they eventuall come out run a UNC tap down the threads and fit new manifolds with Stainless bolts with LOTS of copper grease.
Well after a couple of weeks of penetrating oil (various makes), heating, freezing, gentle spanner wiggling and anything else I could think of, I managed to get 3 bolts out (and back in again so I can use the car). Have now decided it’s going to be quicker and easier to cut the bolt heads off and take the manifolds off to give better access. A sharp tap with a hammer on the remaining studs should release them. Tried it on the one bolt I could swing a hammer at after removing the washer from under the head and it came straight out almost finger loose. Planning to go for it this weekend.
Rob.
Rob.
Sounds like you're getting there Rob.
Before you chop the bolt heads off, try whacking them with something like this...
I made it from a 2ft length of 3/4" round steel bar ( long long ago ), and it's amazing how often it's come in handy.
Holding the long end in left ( insulated ) hand, with the small end on the bolt head, you can redirect the blows from a 2lb hammer in fairly tight places. Should be enough to shock the rusted threads free.
My manifolds were held on with studs & nuts by the way.
________________________________
When I first made it, I flattened the ends of my bar to use as a pry bar, it's original purpose was to free stuck injectors from their housings on marine/industrial diesel engines, but it also proved useful on aircraft, trains, cars, building work, demolition & even self-defence.
It's especially handy for suspension work.
HTH, Good luck,
Glen
PS Don't forget to disconnect your battery lead first. ( see "rocker cover gaskets" thread )
Before you chop the bolt heads off, try whacking them with something like this...
I made it from a 2ft length of 3/4" round steel bar ( long long ago ), and it's amazing how often it's come in handy.
Holding the long end in left ( insulated ) hand, with the small end on the bolt head, you can redirect the blows from a 2lb hammer in fairly tight places. Should be enough to shock the rusted threads free.
My manifolds were held on with studs & nuts by the way.
________________________________
When I first made it, I flattened the ends of my bar to use as a pry bar, it's original purpose was to free stuck injectors from their housings on marine/industrial diesel engines, but it also proved useful on aircraft, trains, cars, building work, demolition & even self-defence.
It's especially handy for suspension work.
HTH, Good luck,
Glen
PS Don't forget to disconnect your battery lead first. ( see "rocker cover gaskets" thread )
Edited by glenrobbo on Wednesday 24th July 13:09
Good luck for the weekend Rob!
When I took some manifolds off a spare engine, the nuts did shear off the studs.
Fortunately there was enough stud remianing in the head to get some mole grips on and they did come out.
The engine was obviously accessible with no chassis around it which made is easy!
Chris.
When I took some manifolds off a spare engine, the nuts did shear off the studs.
Fortunately there was enough stud remianing in the head to get some mole grips on and they did come out.
The engine was obviously accessible with no chassis around it which made is easy!
Chris.
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