dlaing Posted October 11, 2007 Posted October 11, 2007 My best crossover was homecooked and looked alike: I think that design would work great on our bike. I had thought of the same idea, but thought maybe it was overly complex, with little gains over a Stucchi type X-over, but it would probably spit the flow just as well (and probably better if you made more symetrical Y-pipes)while getting even less cross interference than an Xover. On our bike it could shorten the header to beginning of cross-over point. I am not sure how this would effect the curve. Probably more top end, but I would hope it would not kill the mid and low.
dlaing Posted October 11, 2007 Posted October 11, 2007 What it feels like it needs most now is port work and more cam. I think it would also benefit form measuring clearances and seeing if I can up the c/r and tighten the squish. I'm doing all this on my Eldo right now. After that's done, maybe I'll play with the V11 engine some to see what's possible. One guy told me of some intriguing work he's involved in. They cut divots in the i.d. of the ports, like those on a golf ball, and the work so far suggests real gains can be had. I may try that. Both sound like great ideas!
Ryland3210 Posted October 11, 2007 Author Posted October 11, 2007 One guy told me of some intriguing work he's involved in. They cut divots in the i.d. of the ports, like those on a golf ball, and the work so far suggests real gains can be had. I may try that. I think the guy you referred to is on the right track. In die casting it was found that a "pebbled" surface, with the "pebble" diameter around 20-30 thou, substantially increased the flow of metal, to the surprise of the die caster. They had expected the customer's request for that surface finish to make filling the casting cavity difficult. I'm not sure what the optimum diameter of the dimples should in an intake passage.
Guest Phil_P Posted October 12, 2007 Posted October 12, 2007 Well I'd be willing to try the work on the inlet stubs of the Sporti with a round burr in the dremel, but I'm not sure I've got the bottle to do it to the heads.
motoguzznix Posted October 12, 2007 Posted October 12, 2007 I think that design would work great on our bike.I had thought of the same idea, but thought maybe it was overly complex, with little gains over a Stucchi type X-over, but it would probably spit the flow just as well (and probably better if you made more symetrical Y-pipes)while getting even less cross interference than an Xover. On our bike it could shorten the header to beginning of cross-over point. I am not sure how this would effect the curve. Probably more top end, but I would hope it would not kill the mid and low. I tried this double-X-over on my 950 cc Lemans2. Especially the lower rpm range was very much improved. On top I can't say - its a long time ago. But not worse for sure.
motoguzznix Posted October 12, 2007 Posted October 12, 2007 What it feels like it needs most now is port work and more cam. I think it would also benefit form measuring clearances and seeing if I can up the c/r and tighten the squish. I'm doing all this on my Eldo right now. After that's done, maybe I'll play with the V11 engine some to see what's possible. Greg This is exactly what I'm after on my V11. Due to an incident this summer my efforts were stopped half way. I would like to use a short duration and high lift cam like Dynotec or HTM offer for the Guzzis. But to get the full benefit of such a cam, the intake port has to be reshaped for flow up to 11 mm valve lift. By now, there is no increase in flow above 8 mm lift. Even the stock V11 cam opens 10.5 mm! To get optimal squish, I shortened the cylinder barrels by 0,45 mm to get the pistons on top. This amont may be different on any engine. Turning to the heads, the area with a flat chamfer on the outside of the combustion chamber has to be removed completely. This will occur when approx 1 mm is milled off the gasket surface of the heads. The CR will climb to approx. 10.5:1 . Valve to piston clearence may get too tight and must be checked. In case of problems the pockets in the pistons need to be milled deeper. This will be my next steps when time allows it and my new house with workshoop is ready.
Ryland3210 Posted October 13, 2007 Author Posted October 13, 2007 Well I'd be willing to try the work on the inlet stubs of the Sporti with a round burr in the dremel, but I'm not sure I've got the bottle to do it to the heads. It's a very different flow condition in the heads. The purpose of doing it in the inlet passage is to prevent the flow from "sticking" to the walls so it "slides" by faster, in a manner of speaking. My gut feeling is that it would not be beneficial at all within the combustion chamber, but that is just a "gut" feeling.
Pierre Posted October 13, 2007 Posted October 13, 2007 It's a very different flow condition in the heads. The purpose of doing it in the inlet passage is to prevent the flow from "sticking" to the walls so it "slides" by faster, in a manner of speaking. My gut feeling is that it would not be beneficial at all within the combustion chamber, but that is just a "gut" feeling.Take a gander - here's what's going on ...http://tinyurl.com/287hs3
Ryland3210 Posted October 13, 2007 Author Posted October 13, 2007 Take a gander - here's what's going on ...http://tinyurl.com/287hs3 Fantastic!
dlaing Posted October 13, 2007 Posted October 13, 2007 Take a gander - here's what's going on ...http://tinyurl.com/287hs3 That is sooo cool! The flame spread much faster that I suspected, but I guess it does not ping because the heat of the flame is just getting started at TDC. And during the intake you can see why one side of the spark plug has more carbon build up.
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