MODS: I appreciate that this needs to be in Tech but could you please leave it on here for a day or two 'cos I need a quick answer. (Thanks chaps )
Hi, I have a 1989 camper (DG engine). I am hopefully going to be greeted by a "It all went OK" answer tomorrow but, if not, I am going to need a cylinder head. I'm on holiday in it in June so no time to mess around. There is an exhaust bolt snapped off part way down the head (nothing to get hold of with mole grips etc). I have an engineer going to sort it tomorrow and drill out the remains and helicoil the thread. If he isn't succesful I am going to need a replacement head. Will there be a problem replacing just the one head? if there is, is there a way around the problem apart from replacing both heads? I have a source lined up for a s/h head but just wondering if I need to think a little further regarding extent of repair.
Many thanks
Oooooh now you are asking!
Using a hss drill 1 mm smaller than the diameter of the bolt it is possible if you concentrate hard and with a steady hand to drill the shaft of the bolt out of the hole. If you are successful, you can then pull the thread of the bolt out of the hole. It just curls out like a piece of wire. You can then run a tap down the hole to clean up the thread taking it a little deeper than the original bolt and you can then forget about helicoil inserts as they are a little unreliable in an exhaust manifold situation as there is a danger of cracking the casting if the hole is enlarged to take the insert. Use a slightly longer bolt than the original and the job's a goodun.
If the guy is a proper engineer he will know this anyway, if he is just a fitter, he may not.
Thanks for that Bob. He's the local engine specialist and is a good one. Get's a lot of work off my son's garage so he knows he's got to do his very best. Supposedly find out later today how succesful it was!!
btw, I just assumed he'd helicoil it, maybe he will drill carefully.... I hope
Well, the engineer had a go but said he needs the engine out 'cos the bolt is of very hard steel so he needs to get a good angle with his drill so as not to slip off the bolt remains He said he did manage to get a helicoil part way in but he feels it will be better drilling it ouit completely so as not to have to do another repair some time later. Still only charging the agreed figure though So, engine probably coming out on Monday. Might as well replace clutch at same time I reckon.
itchyfeet wrote:To answer the original question yes you can just replace one head that's why brickwerks sell a gasket set for one side
The question was asking if there are any problems changing just one head. Yes, I know I can buy a single gasket, and a single head, and a single everything but I just wanted to know if it would cause a problem. It has become somewhat irrelevant now, I hope!
)
He said he did manage to get a helicoil part way in but he feels it will be better drilling it ouit completely so as not to have to do another repair some time later. Still only charging the agreed figure though 
So, engine probably coming out on Monday. Might as well replace clutch at same time I reckon.
