Re: Bit OT - "A Car is Reborn" ...

Jags were pretty bad for removing the head iirc since the studs stayed in the block, if there was internal leakage then the studs became solid in the very deep head. So there is little likelihood of just undoing the head nuts and lifting the head straight away unless it has been off recently.

It's true that use to be said but many old engines have ally heads on iron blocks and get bad corrosion around the water passages between the two.

I've just rebuilt a Daimler 2.5 V8 - iron block, ally heads - and the passages had to be welded up they were so bad. The Daimler expert who did it, (Russ Carpenter, if any of you remember drag racing in the '60s) said it was imperative when refitting the heads to use Hylomar jointing compound around the water passage ports.

Slatts

Many years ago a work colleague was restoring a Triumph Mayflower. It was one of the first cars to have an alloy head, with an iron block, and the head seizing in place was very common. This guy was enterprising, so he machined some lifting eyes to fit on the head, and with the nuts removed used a block and tackle to pull upwards on the head.

He left it overnight, and in the morning the garage roof was on top of his car...

Chris

Not just old engines - it's remarkably common even today.

(Aren't most diesels still cast iron blocks, due to the compression they run?)

IHMO, this was caused by using either the incorrect anti-freeze or non at all. The correct anti-freeze used all year round prevents such corrosion.

Wasn't it just. Luckily, I was doing a full overhaul, so removed the pistons from below and belted it off using a length of wood and hammer.

Presumably in ye olden days it was not considered good practice to keep the anti-freeze of the day in all year round, since it was definitely common practice to drain the coolant and refill with fresh or antifreeze at the beginning and end of winter.

Quite. It also had a reputation for actually causing corrosion and maybe even blocking rads. So you flushed it out at the first sign of spring. Which could have been a problem this year. ;-)

My first car with an all ally engine was a Rover P6 - and they were adamant you had to use the *correct* coolant all year round, which sort of went against what I was used to. But it certainly worked - I remember replacing a water pump when the car was about 5 years old to discover the inside of the water jacket to be like new. Inside of ally pumps on cast iron block cars of those days would inevitably be badly corroded.

Yes, I have been warned - not just advised - that I must use a 50/50 mix of the correct antifreeze mixture all year to prevent a reoccurrence of the corrosion.

Slatts

Which is, let's face it, just common sense and good practice with ANY water-cooled vehicle.

Rather than "correct" coolant, I'd just use the modern red OAT coolant these days - there's no reason not to, and a stack of reasons why it's better. It's not even that much more expensive.

Just make sure you properly flush through if you're swapping from the older blue-green stuff - they can gel if mixed.

I'm not absolutely certain, but think I read that modern long life stuff isn't best for older cars with copper rad and heater. So I'd stick to stuff said to be for older cars - I use Halfords which has been ok.

I don't think you can still get the original blue stuff that did all the damage.

I rebuilt a 2.5 Dart engine for a client about 15 years ago and it's still probably my most enjoyable engine rebuild. Lovely castings, hollow crank pins with sludge traps and a beautiful elegant design.

The heads corrode badly because they have a very high magnesium content in the aluminium and this one was no exception. However it was a simple job to mill out the corrosion, get it TIG welded with an appropriate grade of wire and then remachine the waterways back to their original shape. I also blueprinted and balanced the whole engine including equalising the deck heights of the block on both sides relative to the crank centreline. It was way out as standard with some slope from front to back on both sides and one side a lot higher than the other. I made a special jig to swing it on the mill through 90 degrees about the main journal housings which took longer than the actual machining but I felt it was worth the effort. If I recall correctly the CR was about half a point higher on one side as stock which is a big difference.

The scary bit was repacking the crank rope seal as I'd never done one before, or since for that matter, but apparently it didn't leak a drop once back in the car so phew!

You need a TV series you do. The next Fred Dibnah. ;-)

Tim

On the Hyster fork truck propane gas engines, it was common practice to use spray Hylomar on the entire head gasket top and bottom. This was supposedly a factory recommendation. Still, it worked fine.