Comper Swift..G-ECTF (Naked)
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Comper Swift..G-ECTF (Naked)
After 12 years of hard work Phil Cozens Replica Comper Swift is now only a year away from flying (we hope).
She came out of the workshop yesterday (thanks to the weather), for a test rigging. And went together very well.
Loads of photos here...
Phils Comper Swift. - a set on Flickr
She came out of the workshop yesterday (thanks to the weather), for a test rigging. And went together very well.
Loads of photos here...
Phils Comper Swift. - a set on Flickr
Last edited by Tupperware Pilot; 22nd Jul 2012 at 06:29.
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That is very nice indeed!
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Comper
Don't know if you've seen this guys but in case you haven't this is Arthur Butler in a Comper Swift flying England to Australia, to retrace Bert Hinkler's great flight of 1928 http://http//www.youtube.com/watch?v=qQWU00ub9ow
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Arthur Butler
Had a great chat this week to the grandson of Arthur Butler - of Comper Swift fame.
His name is Mark Pitts and he is a top boxing trainer whose fighters have included Sakio Bika (v the great Joe Calzaghe) and Arnel Barotillo (v the great Manny Pacquiao).
He says Arthur - who ended up running a big transport company which was then sold to Ansett - taught him boxing when he was a small boy
His name is Mark Pitts and he is a top boxing trainer whose fighters have included Sakio Bika (v the great Joe Calzaghe) and Arnel Barotillo (v the great Manny Pacquiao).
He says Arthur - who ended up running a big transport company which was then sold to Ansett - taught him boxing when he was a small boy
Amazing...
Anyone who is prepared to fly over the shark-infested South China Sea behind a Pobjoy engine has truly got 'Balls of Steel'....! I'm shuddering just thinking about it. 
Comper in bits at Kirton in Lindsey ?
When I did my ATC giding course in 1964 I seem to recall a Comper Swift looking more like a pile of wrekage than an aircraft buried deep in the darkest recesses of the darkest hangar on the station. Anyone know of it or what became of it.
Pobjoys and Sharks
Of course the Pobjoy engine is happy in its lack of knowing if it is over water (Sharks included) or not,as the sharks will not be intererested in munching on its
aluminium and steel.
However this fine engine will give good service if given the required servicing it requires; but has to live with mags that rev twice as much as normal and then deliver a spark to a rather insecure distributor cap.
In fact it was a failing rotor arm that put me down in Iran,and forced a return (over the shark infested Gulf of Oman) back to Dubai on only one mag with a very much 'spare' arm.
It was either that or leave the machine at Jask (not much of a choice).
As an exercise in power to weight and actual thrust the Pobjoy has little equal.
In order to give some chance of survival in event of a ditching (no dinghy) the Comper's empty space was filled with polystyrene blocks.
The engine would be an excellent candidate for electronic ignition.
Prangster, ABTC had had a bit of a prang in the sixties up that way,and was rebuilt by Jeremy Menzies down south.
aluminium and steel.
However this fine engine will give good service if given the required servicing it requires; but has to live with mags that rev twice as much as normal and then deliver a spark to a rather insecure distributor cap.
In fact it was a failing rotor arm that put me down in Iran,and forced a return (over the shark infested Gulf of Oman) back to Dubai on only one mag with a very much 'spare' arm.
It was either that or leave the machine at Jask (not much of a choice).
As an exercise in power to weight and actual thrust the Pobjoy has little equal.
In order to give some chance of survival in event of a ditching (no dinghy) the Comper's empty space was filled with polystyrene blocks.
The engine would be an excellent candidate for electronic ignition.
Prangster, ABTC had had a bit of a prang in the sixties up that way,and was rebuilt by Jeremy Menzies down south.
Last edited by POBJOY; 31st Oct 2012 at 22:38.
Silent Running.
Pobjoy;- The Pobjoys have probably got a better chance of being reliable now with the help of modern technology. They were/are powerful, but pilots in the '30's, when the engines were new, suffered numerous problems and forced landings - and that was often with 'factory-support'. As you state, these were mostly ignition-related issues. Lots of character though and they sound great...!
Ah Pobjoy
Indeed the Pojoy is a light and powerful unit,but aside from the mag situation the valves are a 'weak spot' and need to be changed to a modern material.
The R had exposed valve gear supposidly lubricated by grease (not very well) and the main advantage of the Niagra and Cateract was the oil fed enclosed system.
This system relied on small pipes giving a metered oil supply to the rocker covers (top cylinders),but this can 'silt up' and it is best to actually inject oil into the rocker on a regular basis to ensure some lubrication takes place.
Aside from that i have never had a mechanical failure of the engine or gearbox in hundreds of operating hours.
Used to have 'issues' before changing the valves,but one has to accept that with the territory.
The unit had a fairly low overhaul life because of this,and would have seen valves replaced on a regular basis when they were readily available.
All in all this is a great engine to fly behind and gives great thrust for little weight.
The R had exposed valve gear supposidly lubricated by grease (not very well) and the main advantage of the Niagra and Cateract was the oil fed enclosed system.
This system relied on small pipes giving a metered oil supply to the rocker covers (top cylinders),but this can 'silt up' and it is best to actually inject oil into the rocker on a regular basis to ensure some lubrication takes place.
Aside from that i have never had a mechanical failure of the engine or gearbox in hundreds of operating hours.
Used to have 'issues' before changing the valves,but one has to accept that with the territory.
The unit had a fairly low overhaul life because of this,and would have seen valves replaced on a regular basis when they were readily available.
All in all this is a great engine to fly behind and gives great thrust for little weight.
Pobjoy operations
I think it is fair to say that the 'servicing' and operation of a Pobjoy is more akin to a cross between a sewing machine and a small turbine.
The engine was very small and light for its power,but had to live with materials and oil of the period.
Because the oil has to cope with a reduction gear (SAE 50-60) this is not ideal for good flow through a tiny metering system to the top valves.
As mentioned the cowling system would not have encouraged much extra probing,and indeed the valve design (and material) left little reserve for poor lubrication.
However i changed my valves very early on and ensured the guides got a sploge of lubrication with direct injection between flights.
The Gypsy engines of the time had valves that were 'bathed' in oil due them being downstream in the system.
It is only the top three cylinders that need attention on a PJ so in the 'open' (no cowling) system of a Swift giving them an occaisional squirt is no problem (just like many non aviation engines of the time).
The real benefit comes when you fly behind one,Power,thrust,and that Pobjoy 'growl'. As i soon binned the collector ring exhaust in favour of 'no problem' stubbs the slightly grimy face was a small price to pay.
In non aviation use an early Morgan would be a suitable home for one.
As most of the current engines have the BTH mags fitted it is good practice to open and close the throttle SLOWLY thereby allowing the the mag drive to absorb the input,and giving the piddly little BTH bearing a fighting chance.
Under no circumstances should the 'Gypsy' mag coupling be substituted for the original Pobjoy one, it will not cope with the exta rpm.The original drives may look 'sloppy' but that is the secret of their worth.
The engine was very small and light for its power,but had to live with materials and oil of the period.
Because the oil has to cope with a reduction gear (SAE 50-60) this is not ideal for good flow through a tiny metering system to the top valves.
As mentioned the cowling system would not have encouraged much extra probing,and indeed the valve design (and material) left little reserve for poor lubrication.
However i changed my valves very early on and ensured the guides got a sploge of lubrication with direct injection between flights.
The Gypsy engines of the time had valves that were 'bathed' in oil due them being downstream in the system.
It is only the top three cylinders that need attention on a PJ so in the 'open' (no cowling) system of a Swift giving them an occaisional squirt is no problem (just like many non aviation engines of the time).
The real benefit comes when you fly behind one,Power,thrust,and that Pobjoy 'growl'. As i soon binned the collector ring exhaust in favour of 'no problem' stubbs the slightly grimy face was a small price to pay.
In non aviation use an early Morgan would be a suitable home for one.
As most of the current engines have the BTH mags fitted it is good practice to open and close the throttle SLOWLY thereby allowing the the mag drive to absorb the input,and giving the piddly little BTH bearing a fighting chance.
Under no circumstances should the 'Gypsy' mag coupling be substituted for the original Pobjoy one, it will not cope with the exta rpm.The original drives may look 'sloppy' but that is the secret of their worth.
Last edited by POBJOY; 16th Dec 2012 at 18:43.
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Hi bral et al,
I enrolled at the Cambridge University Library today, looking for Pobjoy drawings, but I failed my quest. I was under the impression that the UL had _everything_ ever published. I'd love to know of other libraries where I could obtain drawings that would enable me to construct an engine in 3D CAD. I have a project in mind, along the lines of rotec, jabiru, but remarkably similar to the Pobjoy.
-Hazel
I enrolled at the Cambridge University Library today, looking for Pobjoy drawings, but I failed my quest. I was under the impression that the UL had _everything_ ever published. I'd love to know of other libraries where I could obtain drawings that would enable me to construct an engine in 3D CAD. I have a project in mind, along the lines of rotec, jabiru, but remarkably similar to the Pobjoy.
-Hazel