Is that your half a FZR250 device? Just found out that Allen Millyard's latest toy goes in the other direction - he's added an extra pot, each end, and built a roller bearing crank. Doing the cams = a fun job, I guess...
Perfect setup for lots of Kiwi/sheep jokes!
Back to opposed pistons (sort of)...
Millyard has been around his Kawas too long, the std plain bearing crank could have been cut, rephased, welded and extended without too much effort.
I note he's using the short rod, early pistons. I can only assume he found a roller bearing rod of that length and wanted to use them.
The top end oiling worries me a little. There's one feed, visible on the front of the head to one side of the camchain tunnel. Oil then travels through the hollow cams to the bearings. I think I'd have put more oil upstairs via a second feed line.
The most impressive thing IMO is the cam cover....OE is a magnesium alloy which fiercely resists welding....
My twin is up to rolling bike stage but held up for want of a working OE ignition. A mate is swapping transistors as he has time, to try and get one of the three I have working... Plus an influx of engines means my time is occupied.
I worried about the top end oiling but for a different reason, he's using 2 stroke rods but still with oil feeds through the crank and I just wondered how much was left for upstairs after that...
He has played with Z1s - Roller bottom end, plain cam bearings, so he's maybe got it sussed.
I've played with Z1's too...they have multiple feeds to the cams - two at each end. Drilled passages in the head and solid cams.
The pic of the almost complete engine lacks the oil and water pumps. They sit under the starter motor and are a sandwich with the oil pump as the inner and the water pump tacked on over that. The std oil pump should have the capacity to do it all as roller cranks don't need pressure - just a minimum volume.
Edit - Oil pumps. I was surprised when I pulled down a late GSXR1000 yesterday - the pump's shrunk ! Noticeably smaller than earlier versions. HP has gone up, weight has gone down, looks like the pump drive ratio has changed too. I'd always believed that you ran into cavitation if you ran the oil pump too fast.
Maybe it goes with the now common reduction in oil viscosity.
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So... if I did want to experiment with a temperature neutral exhaust duct, this would make a perfect test platform.
Eliminating the exhaust heat from transferring to the cylinder would remove the need to worry about watercooling, et al.
Passing all the heat energy into the chamber for stronger pulses.
Eliminating heat transfer to the blow-through for a cooler denser charge..... Couldn't wish for more!
Bringing back Air-cooled 2 strokes, cant get KISSier than that.
But it's not likely to happen this year (my 60th). I'm up to my armpits in the Most 4 Strokey of 4 strokes, a pre unit BSA.
A tribute to my friend Don Newell.
But to demonstrate what I had planned, here's how I was going to achieve 150mph with a 20HP 175cc Victa.
Cheers, Daryl.
Once the inner tube of your thermos flask construction is red hot, it will no longer steal any heat from the exhaust gases, so all energy will be available to the pipe;
Mission accomplished. But how are you going to prevent that red hot tube from heating the washed-through charge? I'm afraid painting it green won't be sufficient.
There may be a little misunderstanding here. KISS is not supposed to be an abbreviation of Keep It Seizing Sucker.Bringing back air-cooled 2 strokes, cant get KISSier than that.
Shame on you Daryl, though you'd get along fine with my youngest brother who's fiddling with a WW2-BSA and a couple of post-war (but what's the difference) Harleys.I'm up to my armpits in the Most 4 Strokey of 4 strokes, a pre unit BSA.
PS: where are you going to plan your world speed record? Recent experience has shown that the surface of the available salt flats deteriorates from year to year.
Front tires will crush the hard surface and dig deep into the brine. An 11" front wheel, even when it's 6" wide, won't help...
Inner tube has little thermal mass and a reduced conductivity & radiation (shiny is a poor emitter). The outer layer of wash-through charge will collect some heat (and cool the duct surface), bulk will pick up much less than normal, because there is less to receive and it's harder to get.
With strongest possible exhaust action, transfer periods might also be reduced, leaving less Time for thermal transfer and/or exhaust duct diameter might be increased, exposing less of the charge Volume to the hot surface. (Perhaps Bultaco knew something, way back when?)
Optimisation of the inner tube dimensions and thermal conductivity with the exhaust/transfer cycle will create a band of thermal harmony in the duct.
Constant temp conditions will then have benefits for optimising compression ratios and spark advance.
It just gets better and better.
..... By not holding heat around the exhaust side of the cylinder, dimensional stability will be dramatically improved.
Useful experiences, almost impossible to get more peak power than BSA did, back in the 50's, but it's amazing the effect that intake and exhaust configurations can have on the torque curve.
Australia has the Best salt lakes available, and close to sea level. Yes, rain does interfere some years, but I'm not planning to retire soon, at least 'til I'm 80, so there is time to make it happen.
Long held and established ideas are always subject to update & revision. This is Nebulous Theorem IV, by Jack Costella. It's a car, not a bike. 149.426mph 125cc S-G
Front wheel is visible through the windscreen.
PS. If your F450 Push Truck doesn't sink into the Brine, your LSR racer is probably OK too!
Cheers, Daryl
Last edited by Pursang; 13th January 2018 at 23:42. Reason: p.s.
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