Why so few single engine Hercules applications?

[cammerjeff]

My bike is a 2013 BMW R1200 GSW. Castrol 4T Synthetic specified for use. Used since new. No issues. Cars - 2020 Toyota Tacoma - synthetic blend or full synthetic recommended; 2016 Ford Edge - synthetic blend or full synthetic recommended. Just keep it out of older engines, right?

Correct, any engine that it is recommended, by all means use it, any engine built in this century should have no issues with synthetic oils.

 

[bdefen]

Some good history here Castrol R - Motor Sport Magazine

As a kid at local motorcycle races, I loved the aroma of a two-stroke Bultaco or Greeves flying by with that wonderful castor oil aroma. They'd use Castrol or the Francisco castor oil. Did four strokes using it in a wet or dry sump system emit much of the castor oil aroma?

 

[pbehn]

As a kid at local motorcycle races, I loved the aroma of a two-stroke Bultaco or Greeves flying by with that wonderful castor oil aroma. They'd use Castrol or the Francisco castor oil. Did four strokes using it in a wet or dry sump system emit much of the castor oil aroma?

Of course, I had a Norton running on the road with it, it smelled like heaven. It was still being used in UK in the 1970s in speedway engines (500cc four stroke singles) the whole stadium smelled of it. By the early 1980s it wasn't being used by anyone in road racing apart from veteran/vintage types. I used two stroke oil mixed with the petrol in both Yamahas and Suzuki two strokes, the factory T/L oil injection system was disconnected. I had an impromptu race in practice at Brands Hatch with a 500cc Manx Norton, it was quite an experience being behind it, apart from the smell the pulses of the engine made my bike vibrate in sympathy and I could hear my own engine, I had to look at the rev counter.

 

[MIflyer]

At Sun and Fun one year they they fired up - but did not fly - a Swedish airplane with a real original rotary engine. Boy, you could smell the Caster oil with that thing! And it coated the fuselage and tail surfaces so well that it was like a layer of varnish. Of course, Caster oil was very important for rotary engines because it did not mix with and be washed away by the gasoline.

One in the 90's a friend of mine went to Bike Week at Daytona Beach and said they were selling Russian made motorcycles with sidecars. Supposedly, they were WWII design BMW's built at the factory the Soviets took back home with them. People who bought them reported that you had to open up the engines and "Scrape the cylinders" after so many miles.

It was obvious to me that those engines were not designed to use modern low friction antiwear oils. And unless you were careful to break them in on "mineral oil" without antiwear additives, as we do with airplane engines, the rings would not seat properly and would be skating over an oil glaze, leading to high oil consumption. But the motorcycle people did not know that and no doubt just poured in modern American oils. "Scape the cylinders" is what airplane mechanics call honing the cylinders to attain a finish that will be easily wet with the oil and also wear in properly.

 

[pbehn]

One in the 90's a friend of mine went to Bike Week at Daytona Beach and said they were selling Russian made motorcycles with sidecars. Supposedly, they were WWII design BMW's built at the factory the Soviets took back home with them. People who bought them reported that you had to open up the engines and "Scrape the cylinders" after so many miles.
.

A near neighbour of mine had one in the 1970s painted like a WW2 side car set up.. The story was always that they were built with captured machinery, in fact Russia bought the license to produce them in 1940. Dnepr (motorcycle)

 

[bdefen]

A near neighbour of mine had one in the 1970s painted like a WW2 side car set up.. The story was always that they were built with captured machinery, in fact Russia bought the license to produce them in 1940. Dnepr (motorcycle)

Did a motorcycle ride on the Magruder Corridor Road in Idaho and Montana in 2006. It's a Forest Service route with primitive areas on either side. About 100 miles long. An iconic trip. One guy along with us, Al, was on a Ural Sidecar rig - the military looking one. Weighed about 1000 lbs, and could barely make 60 mph. Funky, seemed more like an agricultural implement than a motorcycle, but it looked like fun. He and buddy Steve had ridden down from Moscow, ID, and met us at the Idaho end of the Corridor. It was fun to watch him back into parking places. He wasn't fast on the trip, but he was steady. Things were going just fine.

At one narrow uphill section called Dry Saddle, he must have had a moment of inattention and/or loss of control, and launched off the road, tumbling about 50 yards through a boulder field. (I think the bike's handling can be tricky, especially if you have it in two-wheel drive) The bike flipped over throwing him off. It could have killed him, but he was unhurt. It did scare the hell out of all of us. The sidecar was full of camping gear and a case of Corona in bottles. About half the beer survived. We got all the stuff out and up to the road. A passing family gave him (and the beer and camping stuff) a ride to Magruder Crossing campground on the Selway River. We camped there for the night, and Al was able to relax. We left Al at the campground, and Steve rode back home the next day, and came back with his pickup to take Al home. We continued the ride for another three day. A towing service out of Hamilton, MT, retrieved the bike (to the tune of $1,200 - paid by insurance) Insurance also bought Al a brand new Ural sidecar bike.

Ural link: Ural Motorcycles (imz-ural.com)

Photos of the crash aftermath, with Al. Us at the campground that night. Al is the guy with the white hair. It was brunette the morning before the crash.

 

[BiffF15]

Did a motorcycle ride on the Magruder Corridor Road in Idaho and Montana in 2006. It's a Forest Service route with primitive areas on either side. About 100 miles long. An iconic trip. One guy along with us, Al, was on a Ural Sidecar rig - the military looking one. Weighed about 1000 lbs, and could barely make 60 mph. Funky, seemed more like an agricultural implement than a motorcycle, but it looked like fun. He and buddy Steve had ridden down from Moscow, ID, and met us at the Idaho end of the Corridor. It was fun to watch him back into parking places. He wasn't fast on the trip, but he was steady. Things were going just fine.

At one narrow uphill section called Dry Saddle, he must have had a moment of inattention and/or loss of control, and launched off the road, tumbling about 50 yards through a boulder field. (I think the bike's handling can be tricky, especially if you have it in two-wheel drive) The bike flipped over throwing him off. It could have killed him, but he was unhurt. It did scare the hell out of all of us. The sidecar was full of camping gear and a case of Corona in bottles. About half the beer survived. We got all the stuff out and up to the road. A passing family gave him (and the beer and camping stuff) a ride to Magruder Crossing campground on the Selway River. We camped there for the night, and Al was able to relax. We left Al at the campground, and Steve rode back home the next day, and came back with his pickup to take Al home. We continued the ride for another three day. A towing service out of Hamilton, MT, retrieved the bike (to the tune of $1,200 - paid by insurance) Insurance also bought Al a brand new Ural sidecar bike.

Ural link: Ural Motorcycles (imz-ural.com)

Photos of the crash aftermath, with Al. Us at the campground that night. Al is the guy with the white hair. It was brunette the morning before the crash.View attachment 614678View attachment 614681View attachment 614682
View attachment 614677

He's a very lucky man.

 

[fastmongrel]

He's a very lucky man.

I know a guy who slid his bike into a frozen ploughed field. Took him a while to learn to walk and speak, still uses a stick 30 years later

 

[AMCKen]

"You cannot just run Modern Synthetic oils in engines that were designed to use older Mineral based oils. Even in cars you are running the risk of bearing or ring failure, sometimes just seals that fail either because of a certain additive or lack of that additive. "

The engine in my Eagle SX4 was designed in the 1960s. It has been running fine for years with synthetic oil - usually 0W-40. It is primarily a winter driver so the 0W part is especially useful. Can't get that viscosity range with conventional oils.

 

[merlin]

How did that compare with Bristol's own bid for the 4 x 20mm cannon spec, the Type 153 (illustrated in post No.4 of this thread)?

The Bristol design was based on the earlier '151' - 'high-speed' design - just adding bigger wings, accounted for it's short length of only 25' 3"!, perhaps Bristol weren't too confident, hence also offered the twin engine 153A. The B-P P.88a had a span of 39' 6", length 32' 8", w/a 260 sq/f max. wt. 6,573 lbs and max speed of 337 mph @ 15,000' - according to BSP.

 

[A.G. Williams]

The Bristol design was based on the earlier '151' - 'high-speed' design - just adding bigger wings, accounted for it's short length of only 25' 3"!, perhaps Bristol weren't too confident, hence also offered the twin engine 153A. The B-P P.88a had a span of 39' 6", length 32' 8", w/a 260 sq/f max. wt. 6,573 lbs and max speed of 337 mph @ 15,000' - according to BSP.

Thanks. I have a note that the '153' was calculated to be capable of 357 mph. Not sure what power the Hercules was assumed to be delivering to achieve that.

There's a nice three-way drawing of the Type 153 in Goulding's 'Interceptor' (page 101).

 

[sotaro]

The sleeve valve was promoted by Ricardo as a solution to the poor volumetric efficiency offered by poppet valve high performance engines. At that time there was little doubt that the single sleeve valve flowed more air at equivalent rpm. Also, the sleeve valve combustion chamber was more resistant to detonation due to the absence of an exhaust valve. In radials poppet valve engines only had 2 valves/cylinder, so air flow was limited. I am under the impression the sleeve valve and its activation system was more expensive to produce than the comparable poppet valve.

 

[ThomasP]

re the requirement for Shell Aeroshell 100U oil in the Bristol sleeve-valve engines.

During the pre-war and war-time years the standard aircraft engine oil for use in all RAF and FAA engines was required to meet the D.T.D.109 specification. Shell Aeroshell 100U was simply one of the many different manufacturers' blends that met this specification. The Bristol sleeve-valve engines did not specifically require Shell Aeroshell 100U (not in war-time anyway - and I can not think of any reason why they would have required that specific Shell blend post-war.)

re aircraft the could have used the Hercules engine.

 

[Simon Thomas]

I stumbled across this today. From 'Fedden - the lift of Sir Roy Fedden' Bill Gunston OBE FRAeS RRHT 1998 - 2015 Reprint. p 230

Camm's Tornado fighter could have flown with a Centaurus in 1940, but the development of a good British fighter with a radial engine was - in Fedden's view - deliberately prevented by official bias, centered around Air Marshal (later Air Chief Marshal Sir) Wilfred Freeman. Freeman disliked Fedden as intensely as he liked Hives and his team at Rolls-Royce. The antipathy was quite open, and whereas Major Bulman's problems with Fedden never appeared to warp his judgement, Freeman never tried to exercise any judgement on Bristol engines save to reject them. When the Tornado ground to a halt through failure of the Rolls-Royce Vulture engine, the Centaurus could have been fitted to a specially tailored airframe within two or three (months (Fedden sent Camm an engine in November 1940). In fact, to the disgus t of Freeman, Camm did contrive to build a Centaurus- Tornado, and when he flew it in October 1941 it turned out to be the fastest fighter ever built in Britain up to that time. In its original form it reached 402 mph, but with a redesigned engine installation and four-blade propeller it reached 412 and then 421 mph. Later in the war with a Centaurus IV in a further redesigned installation, it reached 429 mph. Camm became enthusiastic, and managed to get a Centaurus fitted to one of his new thin-wing Tempests, which then (August 1942) was called the Typhoon II. Freeman was furious, and had the engine taken out again. In return Fedden said he wondered whether he could get Freeman impeached for seriously undermining the war effort. The Centaurus fighter was not allowed to fly until June 1943, by which time the excellence of the German Focke-Wulf 190 and American P-47 Thunderbolt had made it difficult for Freeman to insist that a radial-engined fighter must be inferior.

Gunston does note that none of the reviewers of the text required the above to be modified.

Why does "d i s g u s t" get auto-corrected to disgust?

 

[Admiral Beez]

I know a guy who slid his bike into a frozen ploughed field. Took him a while to learn to walk and speak, still uses a stick 30 years later

I've been riding for over fifteen years now with at least a 100,000 km ridden, and have never, not once had an oh sh#t moment. I ride to my abilities, always 100% sober, always ATGATT, and never ride until the roads are free of ice, salt, sand and snow. More than half of motorcycle accidents are either entirely or partially the rider's fault - if we control for ourselves we need only worry about those few accidents that are entirely the other guy's fault.

As for the Hercules, this demo rig is impressive to me.

 

[Shortround6]

The sleeve valve was promoted by Ricardo as a solution to the poor volumetric efficiency offered by poppet valve high performance engines. At that time there was little doubt that the single sleeve valve flowed more air at equivalent rpm. Also, the sleeve valve combustion chamber was more resistant to detonation due to the absence of an exhaust valve. In radials poppet valve engines only had 2 valves/cylinder, so air flow was limited. I am under the impression the sleeve valve and its activation system was more expensive to produce than the comparable poppet valve.

All of the above was true when work started on the sleeve valves in the 1920s, much of it was no longer true or of little difference by the mid to late 1930s.
Bristol was using four valve heads in the early/mid 20s but the valves were all parallel which made for small valves. Intake port and manifold size/shape also affect breathing. Bristol went to a pent roof head to get a bit more room for valves. P & W, Wright and others went to hemi heads with valves at 90 degrees or so to each other to allow really big two valve heads and to allow big ports/passages.
The hot exhaust valve problem was moderated by the development of sodium cooled valves. It might not have been eliminated but the sodium cooled valves did run much cooler than the old ones. Likewise many of the other problems with poppet valves ( valve seat problems, valve warping, broken valve springs, etc) were overcome with new materials and manufacturing techniques.
In the 20s most radial engines used very little (if any) manifold pressure (The inline engines didn't use any) with the impeller between the carburetor and the intake pipes often referred to as a "mixing fan" to ensure the top and bottom cylinders got somewhere near the same mixture.
Amount of fuel/air mixture going into and out of the cylinders was highly dependent on the valve opening, timing and good intake tract design (which very often wasn't very good).

Once they fitted superchargers and had a positive pressure in the intake tract on the higher throttle settings the volumetric efficiency of the various head/valve designs tends to become a smaller piece of the pie. Not to be ignored (Wright went to a lot of trouble between the R-1820G-100 and R-1820G-200 engines to improve the port size and shape) but boost pressure was becoming more important in determining the amount of fuel/air going into the cylinder.

See: Bristol Engine Tests

for some of these points.

 

[Admiral Beez]

My vote for single engine Hercules is for a monoplane, all metal retractable undercarriage TSR. Can we get it sooner than the Barracuda? Ideally instead of the Albacore, with the Swordfish soldiering on until our Hercules powered TSR is ready.

 

[ThomasP]

I think the main problem would be the development timeline of the Hercules. The Albacore and the Fairey monoplane TB design used the Taurus partly because there was not a reliable fully developed engine of greater HP available. There is no reason the Fairey monoplane design could not have been built with a Hercules engine if it was available.

The Albacore with the Hercules engine (in the photo that I posted above) was tested and evaluated, but it was decided that there was no operational need for an Albacore with a more powerful engine. Basically, the Albacore could already carry an effective load, and the few extra mph and increased climb rate were not considered worth the expense of money and production time.

 

[Shortround6]

There were a bunch of paper single engine designs in the late 30s using the Hercules engine. None were selected for production or even prototype construction.

The availability of some engines, like the Hercules and Sabre (and Vulture) tended to lag behind the initial announced timing which may have had something to do with it?
Some design groups sometimes offered two or three versions of the same aircraft to the air ministry using different power plants. The Air ministry then selected which version to go with, if any.

Considering the difficulties Bristol had with producing the Hercules in quantity 1940 it is probably a good thing that it wasn't selected for more aircraft.

lets not forget it was selected for the Stirling from the start. From wiki so........
"Prior to the Munich Agreement of 1938, Shorts had received a pair of orders for the Stirling, each for the production of 100 aircraft; however, as a result of Munich, the Ministry of Aircraft Production (MAP) enacted 'Plan L', under which Stirling orders were rapidly increased to 1,500 aircraft "

so there are 6000 Hercules engines plus spares already allocated before the end of 1938 or early 1939. Now how many other planes were supposed to use Hercules engines?
And in 1938/39 the "production" Merlin bomber engine was the Merlin X.

 

[GrowlyBear]

Book title, please. Thank you.