Joined: Aug 2017 Posts: 2,748 Threads: 31
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Location: Auckland, NZ
Chevrolets were about the only car to retain iron pistons post 1930.
Cycles of heat on the stuck piston may help to free. If you have nothing else can be held over a candle! Clean bore with very fine paper. The conrod and white metal are precious so do not damage. The rings are sure to be stuck after piston is pursuaded out. Standing a household iron on the crown can be used to heat and may free. If wear is moderate and piston skirts not collapsed, pistons and bores may be reusable.
The crankpins are drilled to provide communication from the oil receiving troughs in webs to the crankpins. If you have not noticed the oil jets in crankcase, take care not to damage.
Joined: Aug 2017 Posts: 682 Threads: 17
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Location: The far North East of England
Car type: 1934 Austin 7 AVH Van (in bits & incomplete!), 1936 Morris 8 Series I Tourer
23-07-2018, 12:34 PM
(This post was last modified: 23-07-2018, 12:43 PM by Jeff Taylor.)
The numbers you've found on the piston crown show that these are quality Hepolite manufactured Austin Seven pistons - their Ref. No. was RS11063. They're obviously + .020" oversize (Standard bore size being 2.20") with two piston rings at 1/16" thickness and two rings at 5/32" thickness. The 'RS' in the reference number denotes a "Super Drain Oil Ring below Pin; Split Skirt Compensating Aluminium Piston". The good news is that at + .020" the block has only been rebored twice, the first would have been + .010".
Joined: Aug 2017 Posts: 1,230 Threads: 33
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Location: Salop
Car type: '28 GE Cup. '28 AD Chummy '30 RL Saloon. '34 RP Saloon. Too Many toys!
That doesnt look very stuck. Bollock some ATF and acetone mix in the bore and let it sit till it drains.
Joined: Aug 2017 Posts: 294 Threads: 11
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Hello Geoff. What an exciting project! I may be able to help with gearbox and crankcase etc. if you still need parts but I am up in Derby so not very convenient for you.
Ray.
Joined: Aug 2017 Posts: 984 Threads: 6
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Location: Scottish Borders
I like to use a block of wood that covers a large amount of the piston to distribute the force when its hit with a hammer.
Good idea to soak it in a solvent such as diesel. Pour some in from underneath & leave overnight. It will probably find its way through.
Jim
Joined: Aug 2017 Posts: 29 Threads: 0
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Hi Geoff,
Great project you've got there and hats off to taking the hard route of keeping it as an RP!
2nd the heat cycles. Soldering torch from a diy place will do, soak in diesel for a while, heat, tap (2nd the shaped wooded block) and repeat. Hard to explain how hard to hit, it will free up eventually, hopefully the pistons will get another chance to work again.
Tom
Joined: May 2018 Posts: 130 Threads: 12
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Location: Oxfordshire
Got the piston out with the advice above (thanks). Block has now been stripped and it's gone off to be cleaned before we assess what else is needed.
In the meantime, I'll get the crankcase stripped down...
DVLA have now been in contact and the case has gone off to the specialist vehicle section as they said there was an issue with the numbers between what I can find on the car, and what's on their records. At least I have someone to contact there now who has been very helpful so far.
Joined: Aug 2017 Posts: 294 Threads: 11
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It is nice to have someone helpful as a contact point at the DVLA. We have all heard the horror stories of ignorance and indifference but maybe things are changing for the better. Lets hope so.
)![[Image: piston3.jpg]](http://www.g32.co.uk/images/piston3.jpg)
