Reed valves and torque pipe

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Someone just asked me if adding a reed valve will give a torque improvement over having an intake extension and I replied that without a torque pipe I doubt it would.
Let me illustrate:
Yesterday I took my bike for a spin with a standard exhaust on it. Power was OK but not impressive. Then I put on my torque pipe and the thing actually had a power rush about 2/3 of top speed (I thought it was going to wheelie) and was eye opening impressive from half speed all the way to the top. With my torque pipe it is actually a blast to ride. I like getting alongside a motorcycle and then gassing it and leaving it behind while the rider looks at me wide-eyed.
People need to understand that the pipes available to this engine can actually make you have less power at all rpm except top rpm because the strong baffle return wave, at lower rpm, pushes back the fuel mixture into the crankcase. Those pipes are designed for use only at top rpm. A pipe designed for torque increase, along with a reed valve, will increase power from about half speed to top speed. Without a reed valve it is greatly limited because the diffusers return suction wave has little effect on the closed off crankcase area. With a reed valve the suction pulls into the crankcase more fuel mixture from the carb, which then goes into the cylinder for more gas/air to burn, therefore causing more power.
Some people think that "power mods" will make them ride too fast and draw negative attention to them by law enforcement. Not so. With an expansion chamber you can set the top rpm by the header length. Longer causes less peak rpm and more down-low power. Once you have top speed set that way then you can enjoy more hill climbing power and better acceleration. Click onto my signature link to read more about the torque pipe and other power enhancing modifications.
 
The reed valve intake on it's own will increase the amount of air/fuel mixture trapped in the crankcase when the reed valve petals close, as there can be no reversion when the piston starts descending from top dead centre, as is typical with a piston port engine at lower and midrange rpms.

A side effect is a higher crankcase compression ratio which causes higher velocity through the transfer ports (when open) which results in greater mixture motion (turbulence) once the piston is ascending and the exhaust port is closed.
This higher mixture motion more vigorously agitates the air/fuel when the piston enters the squish zone (if the squish is correctly set) and violently forces the mixture towards the centre of the combustion chamber, just prior to spark ignition.

At very high rpms the effect of a reed valve intake becomes less and less, as the power curve becomes more focused towards a very narrow usable rpm range.
In the case of motorized bicycles, it is desired to have a strong & flexible torque curve, starting from low rpms, which has the added benefit of significantly reducing noise.

Adding a Jaguar Torque Pipe with belly mounted stinger gives even more low and midrange torque and further reduces the noise of the engine, as does the reed valve intake, which prevents excessive intake noise; the reed petals stopping the reversive effect; reducing sound being channeled up the intake tract and out of the carburettor.

A reed valve intake is an excellent starting point with noticeable gains in low and midrange torque, but the best total gain would come when adding Jaguars Torque Pipe with belly mounted stinger, if you can get away with a physically large exhaust system hanging off the bike.
 
Hi Fabian,

I dont think the exhaust has to be big. That's a question of design. It's not bad to make a long pipe coming down to a low riding muffler with a side outlet just to keep that blowing oil from getting on the back wheel/ bike.
Otherwise, it's possible to start the muffler/stinger, just from the belly of the expansion chamber.
I wish I new how to add photos here. I'd show you my pipe I made...

Paul

Well here it is! I did it!
done.jpg
 
Thanks! I'm still figuring out how I'm going to connect a stinger to it, something like some hose clamp type tightening. It's all stainless .9mm welded with normal 2mm steel electrodes - electric welding. Not what you want to do. But our welder granny Nadya, she is a super welder and she could do it despite the very difficult task. I ground down the excess on the outside and then sanded and polished it with goya paste...lol! We did it over a week or so, I would make new cones and bring them to work and get them really perfectly round and flat welding surfaces to the fraction of a mm, right on edge to edge. This is important when welding thin metal. We have a large thin cutting disc at work for cutting pipe and steel beams. So I could use it as a grinder with a large flat suface - the side of it. I was able to clean out all drops that came through, so it is perfectly smooth inside of there. Now I gotta figure out what muffler design to make too. Dellorto SHA 16.16 on it's way real soon. And too much to do at work %-D)))
 
more photos from making pipeSDC16638.jpgSDC16641.jpgSDC16629.jpg Take notice of the shock absorber piece, it's from an Ikea office chair, it worked perfect as a form to pound the round shape of my stainless cutouts into cones and bellies. At some points I had to wrap the cones and bellies in some wire to hold the longwise edges together tightly until we could get that first tack weld on and then weld the rest. Note! When you weld cones end to end, you should tack them with 3 or 4 welds around the rign you need to weld and when you put the first tack on you have to hold that top cone down tight on the one under it until the first tack has cooled down good otherwise the thermal expansion will push the cone up and out of place as you weld and as it cools, then you are in trouble)))
 
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They are an excellent set of photos. I love the pic with the vernier caliper and sitting next to it on the table is the delicate; micro-metric fine tuning tool - the splitting axe.

More photos of the stinger and muffler arrangement...
 
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