The engineers at Napier really were smoking something on a whole new level. An adaptation of steam engine tech to combustion engines! Oh if only we could’ve seen what this was truly capable of if it wasn’t for that corporate meddling.
Think about it though. There is no cam shaft, lifters, springs or anything that pushes or compresses springs. EVERYTHING internal is rotary action. VERY quiet. Matter of fact these engines were often referred to as "The Silent Knight". Sleeve valves were very popular at early car manufacturing (1920's). Sleeve valve technology was used even through the second world war in British aircraft. The thing that killed sleeve valve was the cost of machining became prohibitive. Thanks for your input.
@@accountcontact7764 Retired aircraft mechanic here. I never dealt with sleeve valve engines personally, but I have a vintage book from WWII-era Britain that discusses them. It seems that the burning of oil is inevitable in large, air-cooled engines because to the necessarily large clearances involved. However, in a sleeve valve engine, the burning of oil left deposits that actually served to improve the sealing of combustion gases within the chamber. Mechanics of the time. including my engine training instructor in 1964, were in pretty much universal agreement that relatively high-time sleeve valve engines actually had better performance than those that were freshly assembled.
@@Hopeless_and_Forlorn Thanks for the response! I have read comments around the interwebz about how sleeve valve engines in particular have issues burning oil, but I was always suspect of this claim. Can you forward me the name of that WWII era book ?
@@nancydavemastous3815 They ironed out the machining costs but development nearly broke the Bristol company. It’s true that sleeve valves were never as cost competitive as poppet valves and in practice, didn’t have the development potential either. All those stories about 4,000hp Napier Sabre engines are fluff. There were _plans_ to develop a 3,500hp Sabre but there is no record that it ever ran, much less flew. Much less went into service. All the WWII sleeve valve engines were single sleeve: the Bristol Hercules and Centaurus and the Sabre. The Rolls Royce Eagle and the Pratt & Whitney X-1800-SA-G and H3730 were a couple of others in development at the end of the war.
Actually doesn’t seem like much of a problem to me at all. Reciprocating steam engines use this exact same system and they use the steam to lubricate the valves. I can’t see why oil wouldn’t have a problem getting in there just the same.
I can tell you that information. It is in my garage in S.W. Florida. One of our Willys Overland Knight Registry club members built a few of these from a non rebuildable double sleeve valve engine. I wound up getting this from him in a deal where I sold him one of my Knights. There are several of these scattered throughout the country, most of them being owned by private partys. The AACA museum in Hershey has an entire cut a way engine on display. If you are interested in getting one of these let me know. I have parts in process and will be building two of them in near future and doing ebay with them.
The engineers at Napier really were smoking something on a whole new level. An adaptation of steam engine tech to combustion engines!
Oh if only we could’ve seen what this was truly capable of if it wasn’t for that corporate meddling.
Awesome display. Thanks for posting
Different from what I was thinking...still can't figure it out 😂😂😂
Interesting but seems monstrously complex
Think about it though. There is no cam shaft, lifters, springs or anything that pushes or compresses springs. EVERYTHING internal is rotary action. VERY quiet. Matter of fact these engines were often referred to as "The Silent Knight". Sleeve valves were very popular at early car manufacturing (1920's). Sleeve valve technology was used even through the second world war in British aircraft. The thing that killed sleeve valve was the cost of machining became prohibitive. Thanks for your input.
@@nancydavemastous3815 Happen to know if it burns lots of oil?
@@accountcontact7764 Retired aircraft mechanic here. I never dealt with sleeve valve engines personally, but I have a vintage book from WWII-era Britain that discusses them. It seems that the burning of oil is inevitable in large, air-cooled engines because to the necessarily large clearances involved. However, in a sleeve valve engine, the burning of oil left deposits that actually served to improve the sealing of combustion gases within the chamber. Mechanics of the time. including my engine training instructor in 1964, were in pretty much universal agreement that relatively high-time sleeve valve engines actually had better performance than those that were freshly assembled.
@@Hopeless_and_Forlorn Thanks for the response! I have read comments around the interwebz about how sleeve valve engines in particular have issues burning oil, but I was always suspect of this claim. Can you forward me the name of that WWII era book ?
@@nancydavemastous3815 They ironed out the machining costs but development nearly broke the Bristol company. It’s true that sleeve valves were never as cost competitive as poppet valves and in practice, didn’t have the development potential either. All those stories about 4,000hp Napier Sabre engines are fluff. There were _plans_ to develop a 3,500hp Sabre but there is no record that it ever ran, much less flew. Much less went into service.
All the WWII sleeve valve engines were single sleeve: the Bristol Hercules and Centaurus and the Sabre. The Rolls Royce Eagle and the Pratt & Whitney X-1800-SA-G and H3730 were a couple of others in development at the end of the war.
Este modelo fue muy usado en motores de aviones BRISTOL HÉRCULES y tuvieron éxito en potencia..
Looks like a problem x100.
English design?
Actually doesn’t seem like much of a problem to me at all. Reciprocating steam engines use this exact same system and they use the steam to lubricate the valves. I can’t see why oil wouldn’t have a problem getting in there just the same.
This is a Knight system double sleeve valve engine, far worse than the Burt-McCollum single sleeve valve engines Bristol and Napier made.
can you please tell me where this model is located?
I can tell you that information. It is in my garage in S.W. Florida. One of our Willys Overland Knight Registry club members built a few of these from a non rebuildable double sleeve valve engine. I wound up getting this from him in a deal where I sold him one of my Knights. There are several of these scattered throughout the country, most of them being owned by private partys. The AACA museum in Hershey has an entire cut a way engine on display. If you are interested in getting one of these let me know. I have parts in process and will be building two of them in near future and doing ebay with them.