2Stroke Stuffing.
2Stroke Stuffing.
If you use an efficient, screw compressor and can seal the exhaust with the disk, it can work. Will it really be better than the tuned pipe engine that's a lot simpler and lighter? People have tried almost the mechanical solutions to the two stroke's problems you can imagine. Today they only show an advantage in the big marine engines.
Lohring Miller
I'm just not a fan of anything other than naturally aspirated.
Really not even a fan of methanol or nitro.
His enthusiasm and go for it approach are admiring most of the time but this will be a nightmare to get somewhere near durable plus the blower will eat so much power to deliver enough air doubt it'll make it.
Hello everyone,
this is my first message on Kiwibiker, i am very grateful to all of you who shared your knowledge ( sorry for my bad english....).
I have a question about the transfert duct, Mr Overmars, Wobbly, could it be beneficial to have the exit of the inner radius straight with the same angle like the outside radius on A and B transferts ? i ask the question, because i do not see it on the drawing of the rsa ducts .......
Welcome here, Pagi. The inner and outer radius of the RSA A-duct have the same exit angle, as indicated by the parallel upper yellow line and upper blue line in the picture below. But unlike the Honda transfer ducts, the RSA A-duct has no straight at its inner exit. A straight section here would inevitably lead to a reduction of the radius, and keeping the inner radius as large as possible is paramount for good flow.
By the way Pagi, your English is fine, but I can see one point for improvement. I do appreciate you addressing me as Mr. Overmars, but as I keep saying, Mr. Overmars was my beloved father. Just 'Frits' is fine by me.
thank you very much 'frits'![]()
Alex is aiming to have the exhaust and transfers opening at the same or pretty much the same time. But it looks to me that 2Stroke Stuffings supercharged 2S engine will still need normal blow down time area. Because with the transfer and exhaust ports at the same height the supercharger would not develop enough pressure to hold the exhaust gases back from entering the transfer ducts/chamber.
My pick would be to have a normal Blow Down Time Area, an exhaust that assists with purging the cylinder but without the normal 2Stroke return pressure pulse and a rotary valve that closes somewhere before BDC when the cylinder pressure is at its lowest to trap the incoming clean supercharged air/fuel mixture.
The rotary valve timing can be adjusted to close when the pressure in the cylinder is at its lowest. The bonus is avoiding any hot exhaust gas and the pipe has assisted the supercharge to purge the cylinder. The rotary valve can open again well before TDC in fact any time after the piston has closed the exhaust port. Arranged properly there is no need for the rotary valve to see any real pressure on the blade or exhaust heat.
The rotary valve blade does not have to close Top Down either, it could close Bottom Up and in that way it would act like an exhaust port dam and as a bonus get cooled and lubricated by any blown through air fuel mixture.
The blade would also look different. Pretty much the reverse of a conventional blade. The blade parts shape would look much like the shape of the cut out in a conventional blade. It might even be possible to run a double sided blade at half speed to reduce power robbing drag.
At first I thought Alex's idea was crazy but now it looks very interesting, possible even, although I would probably look at a Turbo instead of a Supercharger just to get away from the superchargers power drag too.
Supercharging a 2T for performance is not easy and the Aisin AMR300 is a Roots type, not a screw type so very inefficient. Attached is the best map for it I could find. It does not have a high pressure or high rpm rating, and in the top right hand corner is already absorbing over 5kW.Originally Posted by TZ350
I would not go this route, thermodynamics is against you.
Yes, that was an easier path than the one I tried.
http://www.jmcampbell.com/tip-of-the...or-efficiency/
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
Wonīt work.
Turbo isnīt pumping at low rpm, therefor you have nothing that pumps into the cylinder.
This whole project is just a waste of time and money.
You have superior scavenging in a twostroke diesel, there are valvetrains that can take over 20000rpm, no need to re-invent the wheel.
But there are no compressor aviable that can pump from zero rpm and upwards except roots and screws.
And by that you might need throttle half open just to make it run on idle....
twostroke diesels donīt even have a throttle, they adjust the poweroutput and demand by the injectorpump.
If Alex only wouldnīt fly away in his thoughts and keep his feet on the ground he might acheive something, and by that donīt need to chop wood for a half year to heal his soul![]()
Yes. I hadn't thought about the issue with no pumping at start up. Good Point.
Alex is using a CVT transmission so once the engine is running it pretty much stays near a constant speed. Certainly it could be kept in the zone where the turbo is pumping.
Starting could possibly, be accomplished by a squirt from a compressed air bottle or a good puff from a blower.
Basically a decent blower or compressed air starter pack. A couple of dive bottles maybe. This is after all a land speed bike and once its running it is a one way trip across the salt before refuelling and doing a return trip. The blower or starter bottles could be stacked in the back of the support truck.
Starting a pulse jet with a blower.
Starting a turbo jet with a blower.
Maybe the next thought experiment to try, is starting Alex's turbocharged two stroke with a decent blower.
There are currently 13 users browsing this thread. (1 members and 12 guests)
Bookmarks