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About numbhands

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  1. I have a bit of a noise issue with mine. If you are curious as to the effect of using a silencer similar to those on super bikes, why not pick up a cheap OEM muffler from ebay from say a gsxr 750/1000 and adapting it to fit your pipework? would give you an idea if the concept worked, allthough the resonant chanbers inside wouldnt be tuned correctly to damp all the noise from a big single. In theory a gsxr can would flow enough air for 180 hp on the 1000, so shouldn't plug up the engine too much.
  2. Hi there, just had a read through this, and from what I've read in the past a good result can be had from injecting water to supress detonation, but the volumes of water need to be be tightly controlled and proportional to fuel air/flow. With this in mind, have you considered setting up some a programmable ecu, along with fuel pump and injectors as per a fuel injection system, and then running a water/methanol mix? The only issue i could see would be if the fuel pump would suffer from running water (corrosion, lubrication issues). That way you would have a fully mappable water injection system, where you could closely control water volumes and injection timing at all throttle and rev conditions. Just an idea.... I also have a vague memory of water injection being injected into the exhaust port, with the main intention of this being to cool exhaust gasses at certain parts of the rev range. The cooler gases act to change the speed of reflected pulses in the expansion chamber, and therefore give you a means to effectively change the tuned length of the exhaust system, meaning the power band can be moved up and down the rev range. In a clever system the water could be metered out according to the rpm, and thus keep the system "on pipe" for much longer, like an infinite theory! could be quite interesting to get working
  3. Good work there! I like the way you made up the cone section, never really occured to me to use hydraulic forming to get a nice tapered section, would be a good way to make tapered headers... Got me thinking now! What did you use to generate the pressurised water to expand the welded together sections, and what sort of pressure did you have to get up to? You'll have to let us know what happens to the power delivery, I've never used a megaphone design like that so would be interesting to see some powercurves vs the previous design.... Looks smart with all the welds ground down and tidied up though, and is a super tidy install
  4. I think thats the valve guide boss isnt it? helps to guide the air flow round the valve guides.
  5. I've always taken it as the heat value of the plug dictates how hot the plug electrode gets, not the engine. I cant see how the spark plug would affect the temp of the engine itself, given its comparatively tiny surface area compared to the combustion chamber. i might be wrong, what are your reasons for saying that?
  6. 30 mm intake is right, but remember I've got 3 intake valves so the valve area is about the same as 2 36mm valves? ignition pick up is fixed, but I can probably find a way to move it a few degrees each way... I think the next step is to bump up the compression to 10 - 10.5 , but I'd have to deck the block to do that. The squish at the moment is so large as to be useless ( 2.3mm), but decking the block would close that up to around 1.4 mm (thickness of the gasket). Then I'd have to slot the cams to let me time them in again, make sure I had enough clearance from valves to piston (its tight!) and maybe get the piston pockets machined a little deeper. I have a spare mule engine in pieces, so I'll put that together and get the modeling clay out I think. Performance isn't too bad, but I'm used to a 636 Ninja so its all comparative! I've got the weight down to 149 kgs without fuel, so without making carbon fibre fairings I think thats it I think. Allthough I did buy all the gear I need to do that so maybe if I get bored enough...!
  7. I think you're right there! No airbox, just a foam filter covering both carbs. I know the cam timing is conservative, timing figures are IN open 5 BTDC close 40 ABDC (225 deg) EX open 47 BBDC close 47 ATDC(234 deg) Valves are fairly small, Inlets are 3 x 30 mm and exhaust are 2 x 32mm Compression is low, 9:1 Not fiddled with ignition timing, I'd need a programmable CDI for that but on the to do list, especially if I change the compression ratio.. Not sure if the slides are opening all the way! the air filter was on for all the power runs, but I did swap the slide and spring from the old carbs, so assumed they would open all the way... not sure about that now! If I'm honest I'm happy enough for now. I think more power now = major engine surgery, which means taking the engine out which in my case is an epic adventure! I'll do something with it over winter I guess
  8. As grey racer said above, the iridium plug wont give you more power per se, but its finer point will allow the spark to jump the gap more easily under difficult conditions, ie Higher compression ect. So you only see an increase of power if the standard plug is struggling because of any mods, i doubt a standard engine would need it. Having said that I use one, because my plug is an absolute swine to change and because the iridium tends to last longer than a standard plug i dont have to change it as often. My alfa 156 v6 used platinum plugs for that very reason (manifold off etc) I also believe the imprezza uses them for the rear plugs only because they're difficult to change... Fronts are normal plugs.
  9. Spent 2 hours at PDQ this morning setting up the new carbs and trying spacers, and I'm a little dissappointed with the results: Net result is 1 hp more, and an engine that holds on to peak power longer, with no losses anywhere, and a snappier throttle response. Peak is now a fag paper under 49 hp. The red trace shows what happened with 20 mm spacers, a very minor boost in the midrange, not worth the issues it gives me with relocating the wiring to run the bike like that in my opinion... Never mind, You have to try these things to see what happens! Am running the bike with standard intake length which is the green trace, and I added the blue trace which is the original 33 carbs with standard length for comparison. Still havent reached the magic 50 hp, which is a shame, but spring is here and hopefully the weather will pick up soon, so thats it for now until winter (unless I blow it up) quick vid, filmed it the wrong way so oops. Will do you a fly-by engler when I find a volunteer to stand there while I ride at them. Saw 114 mph with more to come on way home, which was nice...
  10. Got the last spacer made, this is how they sit on the head so ready for tomorrow. The inner one needs blending a little to match the port completely, but no worse than the original carb rubbers so happy with them for now. Might give them a little work at a later date, because it'll bother me other wise! post results tomorrow!
  11. Yup, I'm a metric boy! not that cold really, i'm just a wuss...
  12. Machined up some 10 mm spacers today:- I've built in a O ring to each, so when I make the next two they'll be "stackable" and simply clamp together using longer bolts in the existing holes that currently hold the carb rubbers to the head, that way its a quick swap to check the effects of +10 +20 mm. Hope it warms up a bit for friday, -1 at the mo...
  13. Redline is 7500, but it's shaking so hard by then I dont like to go there too often!
  14. Thanks for the info englert! Since I have a limited amount of room to space out the carbs to lengthen the inlet tract, I've done the maths for an increase of +10 and + 20 mm as well as what I have at the moment. With my current length of 265 mm, the second harmonic is only effective at 8542 rpm ( way above my redline ) and this only drops to 7943 at 285 mm so will be tuning to third and four harmonic. 275mm gives me a ram peak 3 at 6423 rpm with the wave working against me at 7190, which is ok as the torque is rapidly falling away by then anyway, and the 4th ram peak helping at 5176 and hindering at 5612. With 285 mm peak 3 is at 6198, trough at 6860 , peak 4 at 4994 and trough 5415. My thinking is to try the standard length (265) with new carbs, get them set up and get a baseline reading before changing any lengths.... booked in for the first of march, so I'll try to get the spacers I need machined in time, otherwise it'll have to wait for another session. I shall post results! Tanks again for the help, everyday is a school day,