Old Koreelah Posted June 1, 2013 Share Posted June 1, 2013 OK, a friend of mine flew them (Sea Furies) in Korea. Don't recall the real high oil use figure. IN very cold conditions the little rods that moved the 2 sleeves would break because the oil had congealed Bristol freighters were flying out of Essendon for years and plenty of those pilots are known to me also. They are quite noisy but as far as I know the Bristol sleeve valves worked OK. Plenty of "normal" valve radials use a lot of oil. The P&W s could get through a bit and one plane I flew had a large oil tank in the cabin to enable oil to be transferred in flight, to any of the engines. Nev While I was growing up in the 60's, what I believe was a Bristol Freighter would fly over our farm (at Old Koreelah) each week. It made a big impression. A few years back I got talking to an older bloke who was turned out to be the pilot of that aircraft. Small world. 1 Link to comment Share on other sites More sharing options...
facthunter Posted June 1, 2013 Share Posted June 1, 2013 They used to call them Bristol Frighteners. A few had wings come off them. They climbed, cruised and descended at the same pitch attitude . (Like a Thruster). The throttles were up in the roof like a seaplane and they adjusted the noise. I'm not a particular fan of the plane. It was probably designed to fly cars across the English Channel. Quite a few of them were used in New Zealand. The aero museum at Christchurch has quite a lot of Bristol engines of various kinds and a Bristol freighter that you can climb all over. Nev Link to comment Share on other sites More sharing options...
bexrbetter Posted June 1, 2013 Author Share Posted June 1, 2013 How about some forum ediquette guys ... Link to comment Share on other sites More sharing options...
facthunter Posted June 1, 2013 Share Posted June 1, 2013 Meaning back to your engine? Nev Link to comment Share on other sites More sharing options...
rankamateur Posted June 1, 2013 Share Posted June 1, 2013 If you moved this thread to a suppliers page you could probrably run it just however you like. Link to comment Share on other sites More sharing options...
geoffreywh Posted June 1, 2013 Share Posted June 1, 2013 The thread was a discussion about a NEW Australian Engine. Not an old fogie discussion forum on the merits of nasty old aeroplanes (Which I have flown in thank you.) Lets get back to it. For a start would someone (other than me, ) please work out the shape of the combustion chamber. Given that the approximate size would have to be around 50 cc. and bore / stroke? say 85 x 80mm ... I'm tired from painting the baby's bedroom and bailing out the cellar.... Link to comment Share on other sites More sharing options...
bexrbetter Posted June 1, 2013 Author Share Posted June 1, 2013 Meaning back to your engine? Nev No, at least engines in general would be fine. I keep the forum open in a corner while I am working and see the red symbol come up, stop my work so I can answer any questions posed just to find off topic stuff going on. Thanks. If you moved this thread to a suppliers page you could probrably run it just however you like. Besides having a forum donation on the way, or arrived already, I am not selling anything. Yet. Link to comment Share on other sites More sharing options...
bexrbetter Posted June 1, 2013 Author Share Posted June 1, 2013 say 85 x 80mm Say aprox 70 x 70. Link to comment Share on other sites More sharing options...
Old Koreelah Posted June 1, 2013 Share Posted June 1, 2013 How about some forum ediquette guys ... Yes sir. We old fogies will now straighten up and fly right. 1 Link to comment Share on other sites More sharing options...
geoffreywh Posted June 1, 2013 Share Posted June 1, 2013 Ha Ha , very funny. now here's a question, If the bore and stroke are 70 x 70 that's 270 cc per Cylinder. 540cc per "pair" 1620 for a flat "six" But the combustion space would be then 66 or so cc per pair of pistons. That's about 35 mm of bore space. So at TDC there would be 35mm between pistons IF there were no valves... But there are valves and they would have to be about 32 mm inlet and 30mm exhaust .... to open and close they must protrude somewhat into the space between the pistons otherwise compression is too low... So how is that arranged. The drawing shows . a sort of diamond combustion space that looks like it might have some severe side thrust effects ( someone already mentioned this.).....Have you built a test engine as per Harry Ricardo ? 1 Link to comment Share on other sites More sharing options...
bexrbetter Posted June 1, 2013 Author Share Posted June 1, 2013 But there are valves and they would have to be about 32 mm inlet and 30mm exhaust .... to open and close they must protrude somewhat into the space between the pistons otherwise compression is too low... So how is that arranged. Firstly there is no running engine yet but drawings have been done and cases are currently having molds made. Valves are 35 and 32 actually and I have molded, with clay, several combinations of chambers and all looks very nice but you will have to excuse me if I don't actually release that information currently as I haven't decided if it's worth protecting or finalised yet. The engine currently has 4 IPR applications, 2 are now at Pending status and 2 are being searched still. 1 Link to comment Share on other sites More sharing options...
Old Koreelah Posted June 1, 2013 Share Posted June 1, 2013 ..I haven't decided if it's worth protecting or finalised yet. The engine currently has 4 IPR applications, 2 are now at Pending status and 2 are being searched still. ..and I bet that exercise costs as much as the prototype, and takes longer. 1 Link to comment Share on other sites More sharing options...
bexrbetter Posted June 1, 2013 Author Share Posted June 1, 2013 ..and I bet that exercise costs as much as the prototype, and takes longer. Nope, China is around $500 to $5000 per application depending on detail and content level and quite fast depending on search criteria and category. Yes sir. We old fogies will now straighten up and fly right. Not sure when "fogie" starts but I'm in the second half century now! Link to comment Share on other sites More sharing options...
Old Koreelah Posted June 1, 2013 Share Posted June 1, 2013 So the Chinese also outperform western lawyers and bureaucrats! Are patents really worth anything over there? Link to comment Share on other sites More sharing options...
geoffreywh Posted June 2, 2013 Share Posted June 2, 2013 There is a very interesting working model of the four stroke opposed piston concept (BUT with different valving.) at http://ridders.nu ... look under 'Verbrandings Motoren" Link to comment Share on other sites More sharing options...
facthunter Posted June 2, 2013 Share Posted June 2, 2013 Would you accept, the engine is an opposed piston Pocket valve, four stroke engine.? Nev Link to comment Share on other sites More sharing options...
VFR Pilot Posted June 2, 2013 Share Posted June 2, 2013 Correct me if I'm wrong but wouldn't that design be less efficient, ie- one explosion having to move twice the mass ? Link to comment Share on other sites More sharing options...
geoffreywh Posted June 2, 2013 Share Posted June 2, 2013 half the distance.... Link to comment Share on other sites More sharing options...
facthunter Posted June 2, 2013 Share Posted June 2, 2013 It relates to the displacement of the engine. The amount of compressed gas available relates to the same thing. This then has to consider the RPM desired and flow rates available through the ports necessary to get the power you need. Much the same if the engine is a normal configuration with a bigger cylinder capacity instead of TWO . Nev Link to comment Share on other sites More sharing options...
damkia Posted June 2, 2013 Share Posted June 2, 2013 Would you accept, the engine is an opposed piston Pocket valve, four stroke engine.? Nev Poppet valve. Pocket valve is another thing altogether https://en.wikipedia.org/wiki/IOE_engine Link to comment Share on other sites More sharing options...
facthunter Posted June 2, 2013 Share Posted June 2, 2013 Pocket valve is what I said and it is what I mean. The orientation of the valves is not the issue. With the cylinder head sitting as it does regardless of the valve orientation it forms a chamber alongside the bore that connects by a passage. I am suggesting the description fits. I have been building pocket valve engines since 1953, and am not implying anything derogatory by that description. Nev Link to comment Share on other sites More sharing options...
damkia Posted June 2, 2013 Share Posted June 2, 2013 Pocket valve is what I said and it is what I mean. The orientation of the valves is not the issue. With the cylinder head sitting as it does regardless of the valve orientation it forms a chamber alongside the bore that connects by a passage. I am suggesting the description fits. I have been building pocket valve engines since 1953, and am not implying anything derogatory by that description. Nev Certainly not trying to insult or offend but my rationale was the style of valving used is a poppet, and that the inlet and outlet are equidistant from the central combustion area, as distinct from the "inlet over exhaust" where the valves are essentially "stacked" on top of each other at different heights from the combustion chamber with the inlet in the head and the exhaust in the block operated "opposed" to actuate opening. Both valves in Bex's engine exist in an OHC head and are actuated in the same plane for opening (although angled to one another). Link to comment Share on other sites More sharing options...
ozbear Posted June 2, 2013 Share Posted June 2, 2013 Nope, China is around $500 to $5000 per application depending on detail and content level and quite fast depending on search criteria and category. Not sure when "fogie" starts but I'm in the second half century now! What part of it could you put a patent on the opposed boxer engine has been done before not being smart but interested. Link to comment Share on other sites More sharing options...
facthunter Posted June 2, 2013 Share Posted June 2, 2013 Don't want to get bogged down with this Damkia but the essence is in there being a SEPARATE CHAMBER linked by a passage.to the operating cylinder(s) where valves let fuel mix in and exhaust out and fuel burns There are what might be called conventional common styles and innumerable possible variants on the principle. Some have the inlets at the bottom and some have the valves at right angles to the bore axis. I don't believe it matters. but it is a significant departure from "normal" valve in head design to be noteworthy.. It does also bring other considerations into the design requirements. Nev Link to comment Share on other sites More sharing options...
bexrbetter Posted June 2, 2013 Author Share Posted June 2, 2013 Correct me if I'm wrong but wouldn't that design be less efficient, ie- one explosion having to move twice the mass ? One explosion that's twice as big ... Actually it is technically more efficient as there is one less combustion chamber surface to be absorbing heat but minus the less efficient inlet and exhaust flow so ends up at a balance somewhere. What part of it could you put a patent on the opposed boxer engine has been done before not being smart but interested. The secret parts. They are actually called "non-obvious" claims - obviously working! 2 of 4 are done and in Pending status, I will let you know when all are as they are related if you don't mind. They are in the Chinese system so they are effectively still a secret. It's actually pretty boring method stuff though, no "super X3000 rocketboosted world saving" exciting stuff. Link to comment Share on other sites More sharing options...
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