Cylinder head removal

[flyer295]

Ever had difficulty removing an aluminium cylinder head from an old engine without damaging it.

The old fashion way was to use wedges etc. Great if you want to knacker the head and block.

I'm trying to find out what engines particularly have this problem when working on them.

Top of my list is the Jaguar V12. Used in the E-type and XJ's

At the moment I make a tool for removing the head of the Jag V12 but would like to spread my range to other engines.

Anybody know of any others?

Bob

[one eyed mick]

The worst I came across was a Tr7 ,the studs have screw slots but also pass through coolant passages head comes up so far and stops I cut them off with a pad saw! and removed the bits with stillsons allnew studs coated in coppa slip never saw it again

[flyer295]

Thanks Mick,

Is that the 2.5 ltr straight 6 ?

Come to think of it, I had a TR5 some time back and yes I did have trouble with getting the head off but I think they are steel heads. The reason I'm specifically after aluminium is that they are easily damaged if brute force is used.

Bob

[Big Rumbly]

Old trick we used to use was loosen the head nuts just a little, then crank the engine, compression was usually enough to break the seal. I take no responsibility for this tho.

[tapkaJohnD]

It's NEVER the 'seal' between the two faces, block and head.
It's ALWAYS seized between the studs and the head, muck in the interspace.

Triumphs, especially the straight sixes, can be very difficult to get off - unless you take the studs out first, all of them.

New ones aren't costly, so violent methods justified and welding a nut to the top of the stud is a far, far better thing than double nutting, as it applies a heat shock to the stud as well. Get all the studs off, and then hit the head with an upwards stroke, using a soft hammer, or some wood as a drift.

You can fill a chamber with rope, through the plug hole, and then use a breaker bar to turn the engine, pushing the head off, but you won't have enough leverage. Don't use the starter - I have a bent conrod to show you why!

John

[Petrolhead_Rich]

Big Rumbly said:

Old trick we used to use was loosen the head nuts just a little, then crank the engine, compression was usually enough to break the seal. I take no responsibility for this tho.

This would certainly break the seal eventually, or if you remove the cam shafts so all valves are in their closed position then fashion up some compressed air to the spark plug holes then this would apply even equal pressure across all cylinders, although as above, there are clear risks from this method, personally I'd keep the pressure low (~2bar?) and either leave for some time or gentle shocks with a plastic mallet to break the seal under pressure! Obviously I accept no responsibility for anything untoward happening if you try this method!!

[tortop45]

Regarding removing head from a v12 jag engine have a look at XJ restorations web site/face book pages theyve made there own removal tool which seems to work fine.

[flyer295]

Yes, I know. I sold them their head removal tool back in April. Glad to hear it works so well.

I am trying to find what other car engines have this problem so that I can make a tool for them.

Bob

[Little Pete]

Many years ago I visited a respected classic car specialist-who shall remain nameless- and saw a DB6 suspended from a girder with its front wheels off the floor via a block and tackle attached to the cylinder head. Apparently when they opened the next day it still hadn't moved!
Obviously I do not recommend such butchery, er I mean imaginative engineering!

Edited by Little Pete on Monday 16th January 17:04

[jamieandthemagic]

There's a head removal tool available for alloy Alfa twincam heads

http://www.ebspares.co.uk/images/tool.JPG

I've got one, needed it. But the head had never been off on a 71 car, so once the tool ran out of thread and had lifted it 4" I was stuck.

Combo of some lime scale remover down the head bolts, plus bouncing the whole car off the engine hoist finally got it loose.

[one eyed mick]

Little Pete said:

Many years ago I visited a respected classic car specialist-who shall remain nameless- and saw a DB6 suspended from a girder with its front wheels off the floor via a block and tackle attached to the cylinder head. Apparently when they opened the next day it still hadn't moved!
Obviously I do not recommend such butchery, er I mean imaginative engineering!

Edited by Little Pete on Monday 16th January 17:04

One Aston I ever worked on I had to do the same ! ,it did come off over night !

[Wombat3]

Ferrari V8s (especially the 2V / 308 variety) can be a nightmare. Solutions have been designed though :

Plates attached to the cam bearing cap studs & cam cover studs and/or into the spark plug holes & then bolts through onto the top of the head studs to apply the lifting force.

http://www.ferrarichat.com/forum/308-328-sponsored...

Edited by Wombat3 on Thursday 2nd February 09:25

[99hjhm]

Little Pete said:

Many years ago I visited a respected classic car specialist-who shall remain nameless- and saw a DB6 suspended from a girder with its front wheels off the floor via a block and tackle attached to the cylinder head. Apparently when they opened the next day it still hadn't moved!
Obviously I do not recommend such butchery, er I mean imaginative engineering!

Edited by Little Pete on Monday 16th January 17:04

Yes thats common practice, engine crane and a couple of weeks if your not in a rush. There are Churchill special tools for winding the heads off these and they have never failed me.

Done a Jag V12 too, long story but with a drilled and tapped very thick plate the length of the head that bolted to the cam carrier studs it wrenched off, putting the head back on one stud snapped (another long story of very corroded studs and customer with no money) and it needed a engine rebuild and studs spark eroding out (Yet another long story).

[flyer295]

If anybody's interested I make the pullers for the Jag V12 and very successful they are, according to those that have bought one.

It's other car engines I'm interested in so that I can make a puller for them.

Bob

[Perseverant]

In a 1950s "Practical Motorist", I read an article on cylinder head removal - much the same set of problems, especially with alloy heads. They suggested using a thin wall tube fitted tightly over the studs with teeth filed and case hardened. Using lots of oil and a tommy bar to turn the tube, they cut down between stud and head. I wouldn't vouch for it but add it as at least a possibility, or maybe a period curiosity.