ESE's works engine tuner

[TZ350]

Really? How many ponies are in there? 3000?



This will teach you to be more careful with your remarks, TeeZee

Arrrr words and the games we play with them ... ... Glad I said "one of the most powerfull", actually its a bit of a tiddler compaired to yours. I wanted to say aero engine but that would have given the game away. Maybe I should have just said "big grunty engine compaired to a Morris Minor".

development was heading towards 5,000 bhp


There are various numbers bandied about, but this from Wiki.

The progress of jet engine development overtook that of the Crecy and replaced the need for this engine. As a result the project was cancelled in December 1945 at which point only six complete examples had been built, however an additional eight V-twins were built during the project. Crecy s/n 10 achieved 1,798 horsepower (1,341 kW) on 21 December 1944 which after adjustment for the inclusion of an exhaust turbine would have equated to 2,500 horsepower (1,900 kW).^[11] Subsequent single-cylinder tests^[12] achieved the equivalent of 5,000 brake horsepower (3,700 kW) for the complete engine. By June 1945 a total of 1,060 hours had been run on the V12 engines with a further 8,600 hours of testing on the V-twins.^[13] The fate of the six Crecy engines remains unknown.

[husaberg]

Really? How many ponies are in there? 3000? This will teach you to be more careful with your remarks, TeeZee

Some more light able to be shed on this tasty little Italian Aprilia esp the semi active suspension. 1992

Another question was to do with the Dellorto carbs.
Were other carbs tried or were the Dellottos better suited to the Disk valve engine or were there other considerations.
Such as their Italianess or sponsorship (I see there is a sponsor sticker on the fairing) or just as case of sticking with what the team was familiar with.
One last thing was that you mentioned in the pit lane thread about the electric power-jet when did Aprilia implement this?. You also mentioned about a car solenoid or stepper motor. A Fiat Uno one why did you go to a Keihin part.

[husaberg]

10 characters plus the carb pics of the Dellortos of the Pitlane thread.

[2T Institute]

The other question was to do with the Dellorto carbs.
Were other carbs tried or were the Dellottos better suited to the Disk valve engine or were there other considerations.
Such as their Italianess or sponsorship (I see there is a sponsor sticker on the fairing) or just as case of sticking with what the team was familiar with.

Dellorto's have been gracing Rotax engines first , with the bore size growing to 39.5mm on the VHSB body, then after Aprilia took over the engine production the VHSD appeared with a 41mm bore then the first generation S-DAS (stepper motor driven power jet) then the pulsed power jet and the latest VHSG 42mm with the APX electronics .
Unsure if other carbs were tried but never seen an Aprilia RSA/RSW without one. I'm not sure but I think it was more down to Dellorto working closely with Aprilia and a pinch of nationalistic pride. No doubt they work very well and if it aint broke.....................

An area of differentiation seems to be in bellmouth designs which each team seems to have their own idea on what the form should be.

[TZ350]

Ok this is where I am at now. The pumper didn't like it, I don't think it could shift enough fuel. I fitted the 24/28 that had run reasionably well before (28.9rwhp) and found it needed to go from a 140 main to a 150 and spent some time adjusting the ignition curve. It didn't lose power, which it usualy does when I try to improve things and it didn't shit itself on the dyno, so not bad all in all.

1ex + RS pipe and Wobbly polish to my EngMod2T simulation model.

Todays dyno run hand drawn in blue and overlaid on the EngMod2T simulation graph.

Down 7hp on target and cuts off abruptly at 12,000 ish. The interesting thing is the torqe starts to realy pickup towards 11 ish and looks like it should start to fly but no matter what I did I could not get it past the wall at 12K.

At the moment something is choking it, I know I will get it right, maybe its time for that matching Wobbly pipe.

[diesel pig]

Down 7hp on target and cuts off abruptly at 12,000 ish. The interesting thing is the torqe starts to realy pickup towards11 ish and looks like it should start to fly but no matter what I did I could not get it past the wall at 12K.

Is that not what solenoid power jets are for? The Overrev?

[Grumph]

Are you running the resonator between carb and motor ?
It looks a bit like you're running into a bad resonance period - try shortening/reducing volume of the resonator.

[wobbly]

Now Neels has added a facility to produce engine power from dyno power numbers, here is what I have actually measured.
This is dyno curve on a Dynojet 168 with plenty of eddy current load to simulate real road use, with rear wheel Hp.
Then there is the sim of the 485 Cheetah cylindered RZ.
And a check of the difference.
12 to 18% between rear wheel and crank.

PS to TeeZee,before we do a hard pipe - what is the 40mm section at the beginning of the RS125 pipe in your sim - I used this in the sim with my design, is it necessary or can we make a "normal" flange around 25mm long.

[husaberg]

Arrrr words and the games we play with them ... ... Glad I said "one of the most powerfull", actually its a bit of a tiddler compaired to yours. I wanted to say aero engine but that would have given the game away. Maybe I should have just said "big grunty engine compaired to a Morris Minor".

development was heading towards 5,000 bhp


There are various numbers bandied about, but this from Wiki.

Bar and Stroud was a popular sleeve valve engine to be fitted to the early motor cycles. such as Grindley pearless a make later made famous by one C.W.G (Bill) Lacey. (He used J.A.P conventional engines Though)
These engines were popular partly because of there almost silent operation.
unfortuantly it was never developed to the same extent as the multi cylinders used on the aeroplanes and and for cars.
This was also it the wiki article TZee quoted which i found interesting.



http://en.wikipedia.org/wiki/Sleeve_valve

Advantages

The main advantages of the sleeve-valve engine are:

• Increased volumetric efficiency due to very large port openings. Sir Harry Ricardo also demonstrated better mechanical efficiency. An additional advantage of the system is that the size of the ports can be readily controlled. This is important when an engine operates over a wide RPM range, since the speed at which air can enter and exit the cylinder is defined by the size of the duct leading to the cylinder, and varies according to the cube of the RPM. In other words, at higher RPM the engine typically requires larger ports that remain open for a greater proportion of the cycle, which is fairly easy to achieve with sleeve valves, but difficult in a poppet valve system.

• Good exhaust scavenging and controllable swirl of the inlet air/fuel mixture in single-sleeve designs. When the intake ports open, the fuel air mixture can be made to enter tangentially to the cylinder. This helps scavenging when exhaust/inlet timing overlap is used and a wide speed range required, whereas poor poppet valve exhaust scavenging can dilute the fresh air/fuel mixture intake to a greater degree, being more speed dependent (relying principally on exhaust/inlet system resonant tuning to separate the two streams). Greater freedom of combustion chamber design (few constraints other than the spark plug positioning) means that fuel/air mixture swirl at TDC can also be more controlled allowing improved ignition and flame travel which as demonstrated by Ricardo, at least one extra unit of compression ratio before detonation c.f. the poppet valve engine.

• The combustion chamber formed with the sleeve at the top of its stroke is ideal for complete, detonation-free combustion of the charge, as it does not have to contend with compromised chamber shape and hot exhaust (poppet) valve(s).

• No springs are involved in the sleeve valve system, therefore the power needed to operate the valve remains largely constant with the engine's RPM, meaning that the system can be used at very high speeds with no penalty for doing so. A problem with high-speed engines which use poppet valves is that as engine speed increases, the speed at which the valve moves also has to increase. This in turn increases the loads involved due to the inertia of the valve, which has to be opened quickly, brought to a stop, then reversed in direction and closed and brought to a stop again. Large valves that allow good air-flow have considerable mass and require a strong spring to overcome the opening inertia. At some point, the valve spring reaches its resonance frequency, causing a compression wave to oscillate within the spring, which in turn causes it to become effectively weaker and unable to properly close the valve. This valve float can result in the valve not closing quickly, and it may strike the top of the rising piston. In addition, camshaft, pushrods, and valve rockers can be eliminated in a sleeve valve design, as the sleeve valves are generally driven by a single gear powered from the crankshaft. In an aircraft engine this provided reductions in weight and complexity.

• Longevity, as demonstrated in early automotive applications of the Knight engine. Prior to the advent of leaded gasolines, poppet-valve engines typically required grinding of the valves and valve seats after 20,000 to 30,000 miles (32,000 to 48,000 km) of service. Sleeve valves did not suffer from the wear and recession caused by the repetitive impact of the poppet valve against its seat. Sleeve valves were also subjected to less intense heat buildup than poppet valves, owing to their greater area of contact with other metal surfaces. In the Knight engine, carbon build-up actually helped to improve the sealing of the sleeves, the engines being said to "improve with use", in contrast to poppet valve engines, which lose compression and power as valves and valve stems/guides wear. Due to the continued motion of the sleeve (Burt-McCollum type), the high wear points linked to poor lubrication in the TDC/BDC of piston course are suppressed, therefore rings and cylinders lasted much longer.

• Cylinder head is not required to house valves, allowing the spark plug to be placed in the best possible location for efficient ignition of the combustion mixture. For very big engines, where flame propagation speed limits both size and speed, the swirl induced by ports as described by Ricardo can be an additional advantage.

• Continental in the USA conducted extensive research in Single-Sleeve-Valve engines, pointing that they were eventually of lower production cost, and easier to produce, however, their aircraft engines soon equaled the SSV engines performance by introducing improvements such as Sodium cooled poppet valves, and it seems also that the costs of this research, along with the October 1929 crisis, lead to the Continental SSV engines not entering mass production. ( Continental ! Its Motors and its People. William Wagner, 1983, p. 33 ). The same book reports that General Motors had made tests with SSV engines, rejecting this kind of arrangement.

Most of these advantages were evaluated and established during the 1920s by Sir Harry Ricardo, possibly the sleeve-valve engine's greatest advocate. He conceded that some of these advantages were significantly eroded as fuels improved up to and during World War II and as sodium-cooled exhaust valves were introduced in high output aircraft engines.


Mike Hewland with his assistant John Logan, and Keith Duckworth experimented with a single-cylinder sleeve-valve test engine when looking at Cosworth DFV replacements. Hewland claimed to have obtained 72 hp (54 kW) from a 500 cc single-cylinder engine, with a specific fuel consumption of 170 gr/HP/hr -.45 to .39 lb/hp/hr-, the engine being able to work on creosote, with no specific lubrication supply for the sleeve, just the sleeve driving mechanism requires an specially devoted lubrication. Hewland reported also that the highest temperature measured in the cylinder head didn't exceed 150 °C, sleeve temperatures were around 140 °C, T was 270 °C in the center of cylinder and 240 °C in the edge.

A recent SAE paper deals with a high-speed, small-displacement sleeve-valve engine, calculated, but not experimentally shown, to have a higher SFC than the poppet-valve alternative, a non-surprising result, considering the difficulty in obtaining the high intake and exhaust overlap that very fast-running engines require, additional work compares two different side-opening intake strategies for sleeve-valve engines.

[TZ350]

After a bit of fiddling it was starting to carberate realy well, it could even pull away from idle (idles 3,500rpm). Then it began making a hell of a racket, like a hole in the exhaust, I couldn't see anything so possibly a blown head gasket. Anyway its time to take the barrel of and check the piston, I will investigate tommorow.

[TZ350]

EngMod2T

Now Neels has added a facility to produce engine power from dyno power numbers, here is what I have actually measured.



....sim of the 485 Cheetah cylindered RZ, the difference.12 to 18% between rear wheel and crank.

Neels sent me an update today that allowed the creation of a measured power file with a correction factor for transmission power loss.



Blue line is the simulated engine and the Red line is what I measured on the dyno. I used 16% loss as the correction factor which is sort of mid way between the 12-18% on Wobblys chart.

Now I can truly compare apples with apples and overlay my dyno graph as crank HP on the simulators graph to see where I need to look to iron out the power bugs.

This EngMod2T package is great, here I have an expert system telling me what it thinks is possible with what parts (porting, cyl head, chamber, carb) I have compared to what I am getting.

There are obviously problems with my interpretation of the plan, now to find and correct my build errors.

[koba]

EngMod2T



Neels sent me an update today that allowed the creation of a measured power file with a correction factor for transmission power loss.



Blue line is the simulated engine and the red line is what I measured on the dyno. I used 16% loss as the correction factor which is sort of mid way between the 12-18% on Wobblys chart.

Now I can truly compare apples with apples and overlay my dyno graph as crank HP on the simulators graph to see where I need to look to iron out the power bugs.

This EngMod2T package is great, here I have an expert system telling me what it thinks is possible with what I have compared to what I am getting.

There are obviously problems with my interpretation of the plan, now to find and correct the build errors.

Are you saying you dynoed a legal bucket at 33hp?!?!

[Henk]

Are you saying you dynoed a legal bucket at 33hp?!?!

Not yet, these are simulation runs as far as I'm aware.

[koba]

Blue line is the simulated engine and the red line is what I measured on the dyno. I used 16% loss as the correction factor which is sort of mid way between the 12-18% on Wobblys chart.

Now I can truly compare apples with apples and overlay my dyno graph as crank HP on the simulators graph to see where I need to look to iron out the power bugs.

Not yet, these are simulation runs as far as I'm aware.

So is that 33hp on the dyno or is 33hp the sim result minus the percentage loss you expect?

[TZ350]

Are you saying you dynoed a legal bucket at 33hp?!?!

Yes 33 crankshaft hp. (if transmission losses are 16%)

The dyno measures rear wheel HP, the simulation simulates crankshaft HP there is some losses between the crank and what rolling roads measure at the rear wheel.

EngMod2T has a function where you hand enter the rear wheel dyno results and a correction factor and it prints out crank HP.

If the loss is truly 16% (at the moment 16 is a guesstimate) then my bike makes (Red line) about 33hp at the crank at 11,750 rpm, calculated (with guesstimate correction) from the 28.7 rear wheel hp as measured on the dyno. If the true losses are less than 16% then my engine is making less than 33 crank hp. I am just not sure what the real losses are yet.

Husaburg suggested to me that the dyno can be used to measure roll down resistance, I am not sure if thats the same as transmission loss but I will look into it, if it is then I can get a more accurate figure for the correction factor.