Re. my 1949 cylinder head
I posted the question as to how best remove the “stuck” cylinder head on my “Flying Squirrel” on 16-4-04 and was overwhelmed with helpful hints from many people.
For the record, the head is now off, after almost 2 months of trying WD40, parafin, diesel oil, plus gas, heating and chilling-all to no effect.
I then welded the old head nuts onto the studs and leaned on them with a long ring spanner. This attack resulted in 7 studs giving up and unscrewing with no further problems. The remaining 9 studs all broke off flush with the head face. (I presume this may have been at the heat- affected zone following my welding efforts). In between times I would periodically try very carefully tapping the head to check for movement. For this I used a wooden drift up the bore. Nothing doing.
Figuring the old copper/asbestos gasket could well be stuck solid, I then attacked it with a hacksaw blade (having first ground the “set” off the teeth and grinding a sharp hook shape). This was very successful, and I managed to remove almost all the centre out of the gasket. So it was by this time obvious the only trouble was with the remaining studs.
Now things start to get serious!
I carefully drilled the end of each stud using a centre drill in my bench drill, followed by a ¼”drill, then 11/32” drill. The aim being to drill to about ¼” above the head joint face level so I had something to get hold of when removing the piece of stud.
This was not a great success. Although I was using new, high speed drills, it was hard going. The studs appear to be in pretty good steel.
I got to about 25mm deep when it became clear the drill was starting to drift off and I was about to damage the head. So I gave up, admitted defeat and took the lump to a local precision engineering company.
They followed my line of attack, but did it with end-milling cutters in a vertical mill with everything clamped tight. BINGO!!! They left about 3mm of stud proud of the joint face, but STILL the head stuck fast!
A few deft blows up the bores to the combustion chamber dome finally had the bloody thing apart!
They then drilled out the studs and we had a beer!
It is clear the studs were holding in the head because their ends were in the water jacket thus allowing them to “grow”. There had obviously been some leakage up the studs to explain the fantastic grip between them and the aluminium cylinder head.
Needless to say, assembly will be using lots of “copperslip”!!!!!!
I wouldn’t wish this on anyone! But the as Ela Heck, one of the respondents to my plea said, ”It’s a character building problem”. I second that! Thanks Ela, and all the other members who offered their assistance. It is much appreciated.
John E. Smith