Reed valves and torque pipe

Discussion in 'Performance Mods' started by jaguar, Sep 5, 2012.

  1. jaguar

    jaguar Well-Known Member

    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.
     

  2. BigBlue

    BigBlue Active Member

    jaguar,

    Thanks for the post. Always look forward to reading when you post something new.

    Chris
    AKA: BigBlue
     
  3. Fabian

    Fabian Well-Known Member

    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.
     
  4. lazylightning@mail.r

    lazylightning@mail.r Active Member

    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
     
  5. Fabian

    Fabian Well-Known Member

    That's a nice looking pipe.

    More photos please!
     
  6. lazylightning@mail.r

    lazylightning@mail.r Active Member

    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)))
     
  7. lazylightning@mail.r

    lazylightning@mail.r Active Member

    photos from manufacturing process SDC16628.jpg SDC16622.jpg SDC16621.jpg SDC16623.jpg SDC16624.jpg SDC16625.jpg SDC16626.jpg SDC16627.jpg
     
  8. lazylightning@mail.r

    lazylightning@mail.r Active Member

    more photos from making pipe SDC16638.jpg SDC16641.jpg SDC16629.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)))
     
    Last edited: Sep 19, 2012
  9. vermhot

    vermhot Member

    Nice pics man !!!!!
     
  10. Fabian

    Fabian Well-Known Member

    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...
     
  11. lazylightning@mail.r

    lazylightning@mail.r Active Member

    @ Vermhot, Thanks!
    @ Fabian, sure will!
     
  12. lazylightning@mail.r

    lazylightning@mail.r Active Member

    Credit needs to be given to Jaguar's pipe calculator! ;-) The cone layout program is very helpful also!

    If you notice the little paper notes taped over on the pieces, they are notes to remind me the exact mm inner diameters and lengths that I need to get out of each piece. This is not as easy as it seems because you need to change a half mm here and there of your actual final measurements because there is some drift going on. I used that cutting wheel to grind both edges of the lengthwise surfaces to be welded. When cutting the metal out initially it will be off anyway, so be sure it's a little more than you need. This is easily achieved by tracing the cone layout(printout on thin cardboard) with something hard and sharp to put in a scratch, the piece will be bigger than the printout. When adjusting the lateral edges to affect diameter, just put the piece so that the spinning disc is inside of the crack. If you have a stationary disc setup you can compress the part and have it grinding both surfaces flat simultaneously - removing extra metal ideally so the surfaces match in flatness. Keep those calipers near and check frequently so as to not take off too much metal. Compressing the part so it closes completely, holding it closed, to take an inner diameter is tricky, especially when its hot. Removing metal from the ends leaves a lip that wont let you get a proper inner diameter. Make sure it's removed completely from both ends before you start taking down the lateral edges to affect the cone end or belly diameter. Take note that it can happen that you cut it so that you need to take more off at one end of the lateral edge than the other because your cylinder/belly is having a wider diameter at one end than the other(more excess to be removed at one end of diameter than the diameter at the other end). The same is true with the cones, you have to always check both ends and sometimes take metal off at an angle so as to remove more diameter at one end than the other. Take your time and use your imagination.
     
  13. lazylightning@mail.r

    lazylightning@mail.r Active Member

    By the way, that's not a splitting axe, it's my mini-sledge hammer. Good for tapping on the metal piece thats on/around the old shock absorber/hydraulic cylinder.
     
  14. Fabian

    Fabian Well-Known Member

    I say not only more photos, but please make a video and upload it to Youtube :clap:
     
  15. lazylightning@mail.r

    lazylightning@mail.r Active Member

    This is what I mean by cutting disc that I used to grind with. We have a large stationary one at work, but if you have one of these, you could strap it down good and use it. SDC16683.jpg SDC16684.jpg
     
  16. jaguar

    jaguar Well-Known Member

    I like how you pay attention to detail although pipes are very forgiving with protruding edges, etc. Your pipe looks better than mine! :)

    I hope more people follow suit and make their own pipe. It's a great learning experience.
     
    Last edited: Sep 20, 2012
  17. lazylightning@mail.r

    lazylightning@mail.r Active Member

    Thanks Jaguar!

    I was just trying to keep the inner surfaces and form ideally to the calculated image. Since we were using an improper welding system - electric coated electrodes- I had to make those edges meet exactly, otherwise a big hole would appear and drip inside when we were welding it.
    The outside looked rather rough with uneven welds when it was done, so I decided to grind it down even like and then sanded and polished a bit. Not going overboard since I still had jbweld here and there to fill some micro holes and I would never be able to get a perfect finish with that anyway.
     
  18. jaguar

    jaguar Well-Known Member

    Incredible for a first pipe! especially impressive since you used a sloppy electric welder. you've just shown that anyone can make a pipe. and with the plans for a torque pipe anyone can have one better than anyone is selling!
     
  19. lazylightning@mail.r

    lazylightning@mail.r Active Member

    Thanks again! %-D))) Well, the important thing to remember is just to take your time. It took a couple weeks to make because I go to work and all and we could only weld a cone or two every day. But when you order a carb or something else, it always takes a while, so it's the same. Just make something nice for yourself. I cut and pounded a cone or belly or two every day, the next day I would finish tapping on them with the hammer on the shock absorber/form and get them perfectly round and then got and work on the inner/lateral edges so as to effect the diameter of each cone or belly end, then the length had to be adjusted here and there, which will make the cone end wider or smaller depending on the end in question, so it's better to do the proper length first, clean up the inner round edges with a file or hard steel blade of sorts(dont let the lip from grinding grow too much or you cant cut it off and will have to file). Then start adjusting the inner lateral seam edges to bring the diameter down to the exact mating edge with the next piece. Note that you should have some wire rigging to hold it compressed while you take measurements and or do the first tack welds on that lateral seam. SDC16647.jpg SDC16648.jpg
    These photos were made before I sanded and polished it, the welds have been ground down already. Note, I put all the lateral seams on the back side so they won't be visible when the pipe is mounted. The welds are offset a bit. This is important because it makes it stronger and because when you weld the ready cones and bellies together, there will probably be a little v shaped crack at the very end. Though if you are using proper welding then this may not be a problem. Just grind off any excess that get's into each cone and belly as it's being made and then make a final cleaning or grinding inside (do you have a small enough grinding wheel that you can connect to some kind of rod that fits in your drill chuck?). Then you do the last connecting welds that seal it all up. Try to make sure it doesn't drip at all on the final welds so there will be nothing inside the pipe....

    ps. The screen on my camera is out and I cant see to adjust the regime to video, I can only take pics for a while now =-( Something gained and something lost..
     
    Last edited: Sep 21, 2012
  20. lazylightning@mail.r

    lazylightning@mail.r Active Member

    by the way...... Nadya is no sloppy welder ;-) She's hot for a granny too)))
     
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