David;
That DeHaviland engine must have been only lightly frozen if they got it
loose with only hot oil. I didn't have much luck with penetrating oil
either, in my case diesel, in loostening my engine and I left it soaking for
months. The factor that likely helped was that the DeHaviland likely had a
sleeved aluminium block with which the hot oil would likely cause more
thermal expansion in the cylinders then it would with an unsleeved iron
block. This probably was a great help in loostening the rings in this
fashion. In the case of the engine in my car the piston rings were so rusted
in place that I had to boil vinegar right in the cylinders to disolve the
rust. Even so I spent a good amount of time pounding the pistons out with a
block of wood.
One problem with the hot oil trick, other then the burn hazard, is that you
can't pour enough of it into a cylinder, that's resting at TDC, to heat up
the piston and cylinder. Another problem would be that on a wedge head
engine you can't get a straight shoot into the top of the cylinder from the
spark plug hole so you would have to remove the head to pour the oil in. I
have heard of all kinds of tricks for loostening a stuck engine but no one
that told me about them had actually tried them. In the end I came up with
my own which were also the only ones that worked, along with a great deal
deal of muscle.
Best Regards
Arran Foster
1954 Imperial Newport
Needing A Left Side Taillight Bezel and other trim parts.
----- Original Message -----
From: "David Sherratt" <dave-tracy@xxxxxxxxxxxxxxxxxxx>
To: "Online Imperial Club" <Mailing-List@xxxxxxxxxxxxxxxx>
Sent: Friday, April 05, 2002 11:06 PM
Subject: IML: Compression & starting.
> The thread about compression, engines and carbon build up appears quite
> often on the list. A couple of weeks ago I was watching a TV programme
> about the restoration of an old de Havilland Gypsy Moth. The interesting
> part of the programme was the old aircraft's engine. It was froze up, the
> crank could not turn and to avoid any damage to the engine's pistons,
rings
> and liners, the cylinder head was removed (they already tried WD40 and
other
> penetrating oils which didn't work) and a gallon of light oil was boiled
and
> poured into the cylinders. After a few hours the oil had disappeared,
> lubricated the rings and the mechanic was able to turn the engine over by
> hand. Got to hand it to the flyboys for a new old trick that I'd never
> heard of before. Would it be possible to fabricate some sort of funnel
> which would do the same job without the necessity of removing the cylinder
> head? Word of caution - a gallon of boiling oil can do some serious
damage
> to the human body!
>
> Dave
> 60 Le Baron
> England
>
>
>
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