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MG MGB Technical - Cylinder head

I am having some trouble removing the cylinder head. I have used releasing fluid on the studs but the head will not release. I have levered it with a long screwdriver using the alternator bracket and knocked it with a lead hammer without success. What is the best way to release it?
Rod Merrall

Rod,
Yeah, more penetrant down the studs, but sometimes it's just a case of the headgasket has stuck to both the block and head and they can be difficult to release, once it moves it'll come off easy-
Be carefull levering off that waterpump / alternator bracket some heads are quite thin right under where the temp sender screws in and you can damage the head---
If it's real stubborn get yourself a piece of hardwood about 1/2" thick and about 6"-8"ish long and come at it from the other side, get the wood wedged in there on top of that same part of the water pump and the bottom side of the head protrusion and give the end of it a good wack with a heavy hammer and hopefully it will crack the seal, then it'll lift off easy-
Not trying to be a smarty pants, but just double check and make sure you haven't missed a headstud nut.specially the two end ones, it could be easy to undo the rocker gear and the nuts along the side and miss the two end ones if it's a hobby and something you're not doing regularly.
Good luck
willy
William Revit

Rod,
Yeah, more penetrant down the studs, but sometimes it's just a case of the headgasket has stuck to both the block and head and they can be difficult to release, once it moves it'll come off easy-
Be carefull levering off that waterpump / alternator bracket some heads are quite thin right under where the temp sender screws in and you can damage the head---
If it's real stubborn get yourself a piece of hardwood about 1/2" thick and about 6"-8"ish long and come at it from the other side, get the wood wedged in there on top of that same part of the water pump and the bottom side of the head protrusion and give the end of it a good wack with a heavy hammer and hopefully it will crack the seal, then it'll lift off easy
Good luck
willy

How'd you go with the cam followers
William Revit

If it's still in the car and can get compression put the plugs back in and crank it.
paulh4

Thanks I'll give it a go tomorrow. Still can't get 2 followers out Willy; don't really see what else I can do. My friendly mechanic advised to leave them!

Rod
Rod Merrall

Rod
Your friendly mechanic needs to realise there is something wrong going on in there--and needs fixing

In the past I've been able to get them out by poking a piece of stiff wire, like fencing wire, down the pushrod hole and clamping it onto the available top piece of the lifter with some pointy nosed vice grips (have mig'd them on sometimes if they're being really difficult)and then giving the lifter/follower a good up/down workout using the wire. Does the follower come up high enough so that you can see the top of the hole in the side of it, if so you can get your piece of stiff wire and bend a hook on it to get in the hole to get a grip on it instead of the vice grips--give it a real good lift up then tap him back down then another good lift,tap down---it'll give in if you stick to it
What condition were the rest of the followers in

willy
William Revit

Thanks for all the advice. This morning the head would not budge but I sprayed the studs with a penetrating fluid called Deblock. I left it for 3 hours and when I went back the head just lifted off. I couldn't believe it; good stuff.
Rod Merrall

Nice work Rod -- onwards and upwards, only two followers to go--
William Revit

Thanks Willy. I have to say I am nervous about the followers; if all else fails can they be dropped out if the camshaft is removed? Merry Christmas.
Rod Merrall

Rod, The followers can be removed from the bottom if the camshaft is removed first. If your planning to do this you need to remove the camshaft with the block inverted, if not the lobes will hit the followers and prevent the camshaft withdrawal.
R.A Davis

Rod--Merry Christmas-
-Is the engine still in the car.or out----and is it just them two followers No2-4 all the rest came out ok---?
William Revit

Willy Engine is still in car and yes it is just 2 and 4, all the others came out ok
Rod Merrall

It's a bit fiddly Rod but yes, you can remove the cam and get them out the bottom ok with the engine still in there--If you decide to go that way yell out and we'll run you through it--
William Revit

I've removed the cam with the engine situ, but other than rad removal etc, you have to undo the front mounts to get the crank pulley clear of the rack. After doing it, I wished I'd gone that little further and pulled the motor and done other stuff at the same time.

Reading this all with interest as I had what sounded like a blown head gasket. Compressions equal on all pots. Pulled off rocker cover to check gaps. Gaps fine, other than a billion thou gap on front most rocker. On extracting rocker off shaft it looks like oil starvation has completely knackered the rocker bush, as bush dry of oil. I'll take it further apart today and see if the problem shows further down the length of the shaft. Anybody else come across this one before?


Peter Allen

Regarding getting the crank pulley off on a CB it's easier to undo the rack mounting bolts and the column UJ bolt and the rack should come forward enough. For me the UJ splines didn't disengage.
paulh4

Peter the rocker shafts wear for fun. Budget for a new one.

Colin
Colin Parkinson

Re my rocker arm incident, here's one for some post Christmas entertainment:

The engine in question is a 1971 18V that I bought as a back up engine. The idea was to just give it a quick refresh with new rings (it was already on 0.060 bores), big end shells etc. Anyway, I noted that the head had the smaller inlet valves, so as I had a spare 12H 2709 casting with the larger valves I swapped that over. So far so good. Anyway, now on looking at the rocker gear (that came with the engine, and I swapped over on to my spare head) I note that the rear rocker pedestal is the offset oil type. Whereas the head is the earlier inline type, which may account for the oil starvation. BTW, the offset type didn't come in until 1975, so if there's a moral to this tale is assume nothing and pay more attention to detail!


Peter Allen

You won't be the first one to get caught with that Peter, a slot ground into the bottom of the pedestal to line it all up is the go-
I used to use the rocker gear off a Datsun 1500 on myB engined midget racer and that had the same issue--It makes you feel a bit-O bug@er when you find it--but at least you found it---yay
willy
William Revit

Yes, thanks for your commiserations, Willy. That was my second mistake when I assembled this engine. The first was using a three bearing oil pump gasket on a five bearing engine and trying all sorts of methods to get any sort of initial oil pressure...........of course I didn't find this out until the engine was well and truly installed in the car. To anybody who hasn't done this job, the gasket physically goes on, but leaves an air gap under the pump. What larks! If anybody else can use these little contretemps as a lesson learned I'll have achieved something.
Peter Allen

You are not alone, I have heard of others fallung into the same trap. It puzzles me why some gasket sets have both oil pump gaskets in them when it is specifically a 5 bearing set.
Paul Walbran

This thread was discussed between 18/12/2021 and 31/12/2021

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