Cylinder head removal on GT6 Mk3

[Waynebaby]

Hi All,

 

Does anybody have any good tips for getting a stuck cylinder head off a GT6? I've taken the stud nuts off and the head is "loose" enough to allow water/air up the studs and air into the cooling system when I turn over the engine by hand but despite bashing away with a rubber mallet and nearly giving myself a hernia tugging away at the head it is showing no sign of budging! I've used plenty of plus-gas on the studs which seems to be getting down where it needs to be

 

All suggestions gratefully received.

 

Wayne

[JohnD]

First step, remove all the studs.    You can double nut them or weld a nut on to, it doesn't matter 'coz either way you will need new studs, a good move anyway.

Or else invest in a stud remover/driver.  NOT the eccentric cam type that will really damage the stud (which you are going to renew, aren't you?) but the roller type that you can use to put them back in with, with no damage at all.

 

Then, back to the Large Precision Adjustment Instrument (aka hammer).     A mallet may be too kind, a 3lb club hammer with some wood to cushion the blow may shift it, esp. if the energy is directed upwards.

Likewise, a WOODEN wedge into the head gasket.

 

It's never that the head is stuck to the block, but that crud and corrosion around the studs glues it down.

John

[Pete Lewis]

Echo johns clues,

 

once in desperation I had to cut one imoveable stud through the small gap done with a hacksaw blade with a cornflake packet sleeve to protect the faces, the stud end twiddled out with fingers

the remaining stud in the head needed a hard punch and sledge hammer to drift it out .

Pete

[dougbgt6]

The recent "rough running thread" on here is a useful read. I think it said there you could reuse the studs three times but, of course you never know how many times yours have been reused already!  Always use new nuts and make sure they're the right ones.

[Waynebaby]

Thanks for the suggestions and pointing me in the direction of the rough running thread (although I have to admit that if I'd read that particular saga first I may not have started down this route!)

[GT6M]

If  the heads still on, and not took any thing off yet

but are thinking it maybe tuff togit off, then try thee,s first.

 

drain water,  slacken all nuts off cylinder head,   If any studs come oot, all the better, 

can get a ring under the rockers if shaved doon a bit

then run emgine,, blipping throttle to increas CR pressure . this should work head loose

 

if an when its cracked off, but still tight at one end, then bung some rope in the cylinder furtest away frae the loose end,         thru SP hole, and turn engine wid bigg spanner this will lift the head up.

 

Note, if any studs are left in, then it can be awkward for the heed to come off.

 

Also, when re fitting, its a good idea to slot all the studs, so they can be screwed in/oot

same too for all the manifold studs, meks putting them in /oot  so much easier

 

M

[Waynebaby]

I've got 12 of the 14 studs out now using the double nut technique but two of them don't seem quite long enough to let me do this (the top nut only gets a couple of turns of thread) Off to get an impact stud extractor tomorrow. Hopefully this'll get the last two studs out of the way and I can try the sledge hammer and 2x4 approach to get the head to move. If this doesn't work I'll attempt the rope trick. The head is certainly getting looser - turning the engine over by hand produces fountains of oil/water from some of the empty stud holes. 

 

Wayne 

[Pete Lewis]

Johns got a photo of a bent conrod using the rope trip

 

when approaching tdc you can apply far more load than the rods will take

 

if the studs are out it will fall off

 

if you have a small gap appearing dream about the cut it off mode,

 

if the extractor is the three jaw chuck type they are good in an impact wrench

Pete

[Waynebaby]

Finally got the head off today after buying a chuck type stud remover and a mains powered impact wrench. I wish I'd bought the wrench ages ago - what a great piece of kit. Thanks for the advice Pete.

 

I'll be calling Garth tomorrow and see about getting the head refurbished via the club shop.

 

I have a related question about the push rods, each of which has a small abraded area at the very bottom (presumably where they bear on the tappets) Does anybody have an opinion about whether or not the wear marks justify splashing out on new rods? If I do go for new push rods is there any advantage in splashing out still further on the "uprated" rods that Rimmers sell? 

 

Wayne 

[Pete Lewis]

Rods and followers wear into each other best not to mix them keep in pairs

as for the abrasion , hard to to tell , new would likely have flat this makes sure the spherical beds into the follower.

some can wear and you get a pip on the bottom

this may the case and its been filled off

 

as for uprated ,,, why?. Just whats up about it, if you up the valve spring rate then a stronger rod may be

worth a consideration otherwise its not worth any more££££

Just some thoughts pete

[Waynebaby]

Thanks for the advice Pete. I think I'll just put the old ones back in. Cheers. Wayne