RADIO CHECK

[John H]

ANYBODY OUT THERE?
Is there a moderator for this site?
I know of a few who don't know how to post a new topic or post photos.
For those who want to post, go to bottom of home page, click on the 'jump to' box and select a forum. At the top of
each forum is a 'new topic' red box. Click that box, enter your topic and type your subject.
You can also click on the 'board index', pick a forum from there and start a new topic.
Give it a try guys. Why else would you join a forum except to exchange information. Don't jut be a lurker.

[ATinkerer]

Still here John.
T he site has been a bit quiet lately. I think yours is the first post since Thanksgiving and the bike show.

Gordon

[salt-racer]

Hi Guys

I guess it's about time I chimed in.
The Seattle motorcycle show was a blast. The Sound Riders sponsored my entry 'Super-Fly II' and did a wonderful job, I'd certainly participate again if invited. My bike was parked next to another Land Speed Racer, an un-faired kawi 4 cylinder running in the 1650cc class. I sat behind the bike most of Saturday (sitting in a comfortable and very cool racing event chair loaned by Don @ P.A. Power) answering questions and the crowd continued until 7:00PM.

My plan for Bonneville next August 2015 is to run the Kawayami 125cc Hybrid (super-Fly II) then hopefully design/build a new bike for 2016. Initial planning is already underway for the next bike which will be a blown 50cc light-weight, un-faired going against a 75mph record. I will have one of my son's ride the bike (much lighter and skinnier than me).

Of course, I will not be building your ordinary, everyday 50cc race motor as mine will be a Reverse Uniflow design. What the hell is that.....! It's a 2 stroke with entry charge air/fuel fed into the cylinder through common poppet valves in the cylinder head as a 4 stroke (except all the valves are converted to intake duty) and spent the charge is blown out at bottom of stroke through a series of ports (belt line) exiting the engine as the piston uncovers them. All the flow is in 'one' direction and not 'Looped, hence the name "Uniflow".
This configuration allows for incorporation of the 'Miller-cycle' and also 'True' supercharging because the exhaust ports close while the intakes remain open, effectively charging the cylinder! Fires every stroke, twice the fun as a 4 stroke!

Anyhow, that's what's happening at my shop......
George

[ATinkerer]

Should be an interesting design. I'm fairly familiar with uniflow steam engines (old, obsolete mill service) but don't think I've ever seen an internal combustion engine based on the principle.

Gordon

[salt-racer]

Hi Gordon
Yep, this sounds about right.... like I feel often, "Old and obsolete"!

I have been interested in the Uniflow principle for quite a while and have seen the steam engine subject pop-up whenever I've done web research. This is something that I'd like to discuss with you (maybe next meeting)? Everything old is new again sometime.
Although, I've never seen a uniflow in person (or at the race track), I don't see why it would perform well.

George

[ATinkerer]

The weakness' for the steam engines was the inlet valve mechanism, and the bore variation due to the temperature variance.
Getting the spring rate correct should be interesting for your supercharged version.

Gordon

[salt-racer]

Hi Gordon,
The toughest part of the uniflow valve mechanism is going to be valve springs. The uniflow operates with the cam shaft spinning at crankshaft rpm's. On your typical (small) 4 stroke 14,000 crank rpms is about the max you can spin before suffering from things like; valve float, harmonics, fatigue, etc (hell in a hand basket) and the cam is only spinning at 1/2 crank speed or 7,000 rpm! I'm currently designing this Uniflow to operate at around 9,000 max crankshaft rpm's and that means the cam is way beyond destruction also spinning at 9,000 rpm.

One answer, F1 style Nitrogen springs, elimination of the springs all together. I think this is even better than the desmo system, and believe it or not, is much simpler. John H and I (along with another John, John K.) have been discussing the Pneumatic valve system for the last couple of weeks and I think it's doable!
Loose those damn springs.....

George

[ATinkerer]

Will be interested in seeing what you come up with. If I understand the concept correctly, there is still a resonance consideration with gas springs, just not the torsional spring rate like in a coil spring. I lost track of the process, but someone was experimenting with electrical solenoid process valve actuation also. They had heating problems the last I heard, but that was a while ago.

Like I commented, I'll be interested in how the engine progresses.

Don't know if I'' make the next meeting, but will try. Have my son arriving in Portland that day, and I have to go get him.

Good luck with the new bike.

Gordon

[Lotus54]

So like a reverse Detroit Diesel?

Sounds fun!

[salt-racer]

Yes, exactly, Lotus!
The same as the Detroit Diesel except reverse flow direction, from top-down instead of bottom-up.
The primary reason I choose this direction was to keep the heat out of the cylinder head and valve mechanism. I plan to run strictly methanol to start with, should be self cooling with four intake valves in the head. BTW, valve head diameter will be around 10-11mm (cute little suckers).

George