2 stroke diesel

[Jocalopse]

While I am slowly assembling the parts for my first diesel bike build, Yan Clone, CVT, small light frame etc. the thought struck me. Has anyone ever used or know of the existence of a small displacement single cylinder 2 stroke diesel? I ask partly out of curiosity and partly because it would make a good motor candidate. While about as complicated as a four stroke the 2 stroke would make more power per cc of displacement, I realize it wouldn't be exactly double, but it would be greater than a 4 stroke of comparable size. I know of industrial multi-cylinder engines, I've never seen a single. If figure if anyone would be able to point me in the right direction it'd be you guys.

[Jocalopse]

?

[gilburton]

There is not much info on small 2 stroke diesels. Perhaps something along the lines of the Bernard Hooper engineering stepped piston design would work as a diesel??
It was tried in prototype form in the Norton Wulf.
It might have a use as a diesel as the stepped piston would force in the fuel without the extra complication of turbo or supercharging??
It's a pity that this engine was not taken up by a mainstream manufacturer as it offers lightness and the power of a 2 stroke without the oil being added to the fuel.

[stormcoat]

Yes, I know of one. If you ever had Howard Rotovators in Canada, look for one with the Hirth two stroke diesel. They were once popular with allotment holders in Britain. The engine is a single cylinder two stroke diesel of about 500cc. Look it up on the net.
(Howards sourced engines from several different suppliers, some petrol and some diesel, so you will need to look carefully.

[Stuart]

I was once contacted on here by a guy down under who had an interest in them. I have no details about them though. Pretty violent engines and not very fuel efficient I suspect Might be good fun in a small bike though

[Jocalopse]

Ok I gusee this is a no go, the only rotovators I could find info on were all PTO driven. SO I guess I'll have to settle for a Yan Clone. Honda Rebel 250 frame has been secured, will be picking up engine within a month then CVT shortly afterwards. Hopefully I'll be able to have a diesel bike assembled before the end of summer. Thanks for the info gentlemen, I appreciate it.

[Blunt Eversmoke]

As for small two-smoke diesels, there were alone here in Germany the aforementioned Hirth D23 and D24 engines, ILO (sometimes written JLO which is due to a misguiding shape of that capital I) DL325 and DL660, Holder (later Sachs) had both one-lungs and a three-cylinder.

Especially the ILOs are quite interesting since both are light enough to fit into a bike with 50 kilos for the smaller and around 70 or 80 for the bigger one; alas, the power of the smaller one is but 7 hp; 12 for the bigger one. One suspects they were more breakage-prone, at least, the Hirths and the Holders and parts for both makes are sold over ebay way more frequently than for ILOs - because more of them survived?

Stihl diesels are of same qualities as the ILOs, but even more rare to come by.

AFAIK, all of those share a common problem, and that is being crankcase scavenged. Of course, no oil(or fuel, for that matter) is carbureted here, instead, the engines have oil drippers at the critical places, served by a separate fresh oil pump. That means oil is still being burned (albeit less than in a two-stroke gas engine, about 1 litre per 15 hours), and emissions are gonna stink
Also, scavenging is controlled by cylinder ports solely, without port discs or the like, and that means even if one were to supplant crankcase scavenging with a blower (and sump lubrication?), super- or turbocharging would be very hard to achieve.

To summarize: Want a 2-stroke diesel? Convert a 4-stroker, you're gonna have more of it.

[Stuart]

This 2 stroke diesel concept design was recently sent me. See what you reckon.

http://kyledellaquila.com/Benchmark2/index.html

[Blunt Eversmoke]

The engine is the OPOC thingy well known already. Would sure make a good bike engine if ever produced commercially (and sold at some reasonable price, of course).

Now, the bike proposed on the site... It has some of the refined aesthtic appeal of a puke puddle. I'd like one

[BertTrack]

Anyone seen this one before?

http://www.youtube.com/watch?v=r3-VLNjwIsg

I know they were working on it in the past. Don't know what came out of it.

Doesn't have an injector, variable compression and 2 stroke.

It ain't big but it doesn't need to be.

[Blunt Eversmoke]

Had'em discussed here https://www.dieselbikeforum.com/view ... =21&t=2033 and here https://www.dieselbikeforum.com/view ... f=21&t=321, not to any degree of completion, of course.



To make a long story short, yes, might prove an interesting alternative to both petrol and true diesel engines - if built in some decent size. 18ccm is a wee bit small not only power wise - the small volume/surface and ratio of the resulting combustion chamber and the cylinder mean that both friction loss and thermal loss are quite high. Thus, fuel usage back in the day was 0,756 kg per KW of power an hour, with a modern diesel managing >0,272 kg. Even higher was usage measured for a modified replica http://www.practica.org/products/under- ... sel-engine with 0,900 to 1,1 kg per KW an hour.

Taking a decent-sized two-stroke (one with a healthily dimensioned crankshaft, above all), one could swap the head for a modified cylinder/ adjustible counterpiston arrangement to see how well that performs.

To make it even more intriguing, there actually WAS a bigger HCCI engine with variable compression - alas, I forgot the name of it. I only know that it was Italian, made in the 1940ies(IIRC), and had 40ccm. If any Italian (or, indeed, anyone knowledgeable on the topic) stumbles upon this thread here, please inform us!

More info on the Lohmann: in German http://lohmann-motoren-werke.de/media/c ... 144225.pdf, some feedback from an actual user http://www.motoredbikes.com/showthread. ... -woe/page2

[Stuart]

Those little 2 stroke diesel's remind me very much of the really high revving Japanese race bikes back in the day. Didn't one have a six cyclinder, 250cc? It revved to something like 22 or 25k RPM. I remember it would blow people over if they were foolish enough to walk behind it when the mechanics were throttling up
On their own these mini two stroke diesel's may not be much, but if someone were to start bolting them together .......Perhaps we'd end up with a bike altogether louder, thirstyer and generally more violent that some of the 2 strokes from yesteryear

[Blunt Eversmoke]

As destiny has it, here a Holder double-barreled lump on German eBay.

18 (later versions: 20) HP @ 2300 RPM. Other figures I cannot find, especially the weight would be interesting. However, it can hardly exceed 125 kilos or somesuch.

This and an old BMW/Ural/Dnepr frame, anyone?

[gilburton]

I've had a closer look at the bernard hooper engineering website and they have indeed developed diesel versions.
All it needs is someone with money to invest I suspect??

[johnr]

iirc werent ford experimenting with 2 stroke diesel engines for small fiesta sized cars in the 1990s, i seem to recall that queens university belfast were involved somehow too. from memory they were getting decent performance with a turbo and exceptional economy too.

[johnr]

and that opposed piston engine with the 4 pistons in just 2 cylinders is very reminiscent of the deltic train engine built in preston in the 1950's, bit big for a bike, but they were fitted in boats, iirc they were using 34 cylinders with 3 crankshafts and 48 pistons with a turbocharger and getting over 3500bhp. though the engine would have been the side of a transit van!!

[Stuart]

iirc werent ford experimenting with 2 stroke diesel engines for small fiesta sized cars in the 1990s, i seem to recall that queens university belfast were involved somehow too. from memory they were getting decent performance with a turbo and exceptional economy too.

John, I saw that Ford Fiesta 2 stroke but I don't think it was a diesel. It is at the Haynes Motor Museum.

[Drumheller]

www.2si.com

37 hp two-stroke diesel engines. They are called "Mixed Fuel" engines.

[Blunt Eversmoke]

http://www.2si.com

37 hp two-stroke diesel engines. They are called "Mixed Fuel" engines.

Can anyone explain what the smaller cylinder on top is for? I don't grok it.

I hope they made a typo in the consumption figure, it would mean this engine guzzles around half a litre per HP/hour. Mightily rich, because standard small diesels only consume around 0.3 litres per KW/hour.
Would only make sense for the military (fuel commonality) of if you have unlimited access to cheap or free waste oil and a means of filtering/"washing" it properly.

That said, their smallest multifuel has a somewhat better figure - depends on what the 75% power is for this engine. If it is approx. 5,5 HP (full power being 7) the figure is as dismal as the one above. If it is 75% of 12 HP (9 HP), that would give 0.25 litres per HP/hour and would be pretty much OK. Someone ask them?..

EDIT: Found what the little cylinder is there for. It is for fuel-air-mixture injection, and is licenced from Piaggio. No fuel goes out the exhaust port because mixture only enters the combustion cylinder when the ports are all closed. Looky here.

[pietenpol2002]

The 2si is nothing to get excited over. It's merely the old (and I do mean old) Cuyuna 215cc single that was used in snowmobiles and the early ultralights. This is indeed an example of a petrol engine being converted to diesel to meet the military's need for a single fuel force. As discussed here before on the board, it's not really a diesel even though it "burns" diesel. But then, it will burn just about anything as evidenced by the reference to "multi-fuel" and the need for a spark plug. If Rudolf were here today, he could probably get this thing to run on his original recipe of coal dust

There's simply more money in tapping the taxpayer to fund military "R&D" instead of building for a real market.

[zarquon]

http://www.2si.com

Latest News on this site are from 2003! And it was their "MARKET DISCONTINUATION NOTICE".

Maybe this happens for some reason ...

[Blunt Eversmoke]

Meanwhile, on German eBay we see

cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&i ... ink:top:de a 18 hp double-barreled Slavia lump located in the Czech Republic, 46401 Horni Rasnice. Worthy candidate for a Ural/Dnepr rig? Should anyone happen to tour Czechia, might want to czech it out