Is anyone out there converting a petrol engine to diesel?

[IgorVigor]

I am only relaying the information I have got about LR 2286cc engines.
The only real weakness on the original 2286cc engines were that they only had 3 crank bearings.
The diesels were slightly more prone, but both engines if revved too hard, would flex the crank, and then it could break.
later engines (1980 on), they fitted 5 bearings so they dont flex.

I dont know if anyone knows anything about LR's though.

The 2286cc engines weren't at all revvy :S
The Diesels max rpm was 4000rpm, the Petrols was 4500rpm.

I think to convert a bike engine to a diesel, I think you would need to work out the best bike to do it on.
Something that originally revved to 10~15k rpm probably wont be a good option.

I reckon an old Honda Goldwing, or similar. Engines that only rev to say 7k rpm as petrol.

As for the converting petrol bike engine to diesel ,the thing is, sleeving the cylinder with a thicker sleeve than the stock petrol (you would lose some cc, but increase cylinder strength)
Head gasket, I would change to a solid copper one (stronger, more pressure resistant)

Might have to play with this myself

[sbrumby]

The Landy was a special case, the block which did both was made heavy, heavy is good for a Landy as it weighs 2 ton and can pull 3.5 ton. I owned a 109 lwb for a good while. 120ft turning circle but with no power steering it took 60foot to get the lock on. Without the overdrive you could not hear your passenger at 55mph. Good fun though and totally reliable.
On the subject of converting, petrol to diesel, if you think it is an easy route, think again, apart from the engine not able to stand the pressures, are the valve timings the same? Where do you get the extra cam from to drive the injector pump?
The problems to overcome would outway any savings 10fold. And you would end up with a bike half speed of original.

[IgorVigor]

I have a S3 88" Petrol

Slightly better turning circle than the LWB (same 4.1 turns lock to lock steering box though )

The SWB is even worse than the LWB at speed :S

At least the LWB had the larger diameter wheels
Was yours a diesel or a petrol?

Anyway, back on topic

I didn't say it was easy, I just made a point about the land rover engine.

If you took a bike engine, sleeved the cylinders with heavy duty liners, replaced the cam(s), worked out a way to drive an injection pump (some engines suchs as the Ford Endura D, use a belt, and the later version used a chain I believe), upped the compression (skimming the head, longer stroke), beefed up the crank, fitted injectors (spark plug hole should work).

Those are the main issues to address. It is possible, most likely expensive, and your bike would be as fast... But the achievement would be fantastic...
Main thing I would reckon, is to do a direct injection. That way you could utilise the spark plug hole for the injector, the compression ratio would be lower (and closer even as standard to a petrol engine) e.g. high performance bike engine 10~12:1 compression, DI diesel 16:1 would work...
I myself have seen CBR600 engines at 15~16:1 compression with a water injection kit (to stop pre-ignition/detonation), which is something you wouldnt have to worry about on the diesel...

And as for cold starting, you don't need glow plugs...
As most of you will already know, little stationary diesels dont use glow plugs even now.
Certain engines (like my Lister LT1) use a small plunger, into which you put some oil (same grade as engine oil preferably) and as you crank the engine you push the oil into the cylinder to aid starting on a cold morning.
Other methods include a heated element (ceramic heaters use them) in the intake to heat the incoming air (Lister used it on some engines)
Ether is a commonly used method (not just from a can, some big old diesels had a system that gave a squirt of it)

And if you really want to go mad (might be a project for someone to try on a small diesel) there is the Coffman engine starter (and variants) which use a blank shotgun cartridge to force the piston to move down quickly, while also creating a lot of heat... I though about making a system for a stationary diesel possibly using the smaller pistol blanks (.22 shorts probably wouldnt have enough pressure, .22 longs might on a small engine, 8/9mm blanks probably would work for a small diesel quite well. A prime example of a shotgun starter is the old Field Marshall tractors, powered by a big (up to 3.8L I think) single cylinder 2 stroke diesel)


Just some ideas

[Nanko]

Is it really just the compression stressing the conrod , bearings and crankshaft ?
I reckon the combustion stroke gives a lot more force.
When the torque figures of the petrol and the converted diesel are about the same , not
much can go wrong. ( I think)
Here in the netherlands soundemission is a part of the tests to get a bike streetlegal , otherwise I would give converting a Guzzi V50 a try.

[IgorVigor]

Its sort of too do with the compression.

The more you compress a gas, the harder and faster it tries to uncompress, thus the pressures increase.

Now the other thing I forgot to mention is the Semi-diesel, or Hotbulb engine.
Now bear with me here...

They normally had compression ratios as around 3:1

The main difference to a diesel engine (apart from the compression ratio) is when the fuel is injected.
In the diesel it is injected when the air is compressed, for the maximum heat. The hotbulb engine though, injected it during the intake stroke.

The heat of the combustion then keeps a vaporiser hot.

A variation of the hot bulb is the glow engine, as used in R/C cars/etc...
The heat of the combustion keeps the glow plug element glowing.
The main difference is the glow engine uses a carb, not a timed fuel injection.
But the basic principle of the engine is the same.

On both engines the mixture can be adjusted to either raise or lower the temperature of the bulb/plug.

On the glow engine, the richer the mixture, the cooler the plug becomes, effectively retarding the ignition, reducing power.
leaning the mixture, does the opposite, and increases power.

On the hot bulb engine, its very similar.
Under low power (no/low load) to stop the bulb cooling down, you throttle the air intake, allowing less cold air into the engine.
Similarly, the more load you place on the engine, the hotter the bulb will get.
To stop the engine getting too hot and preigniting the fuel, water could be dripped into the intake.

The main problem, is that it could take up to 5 minutes for the engine to warm up. (Blow torches were used to heat the vaporiser)

Now the other method that was used later on was a sparkplug and trembler coil.
The engines were started on petrol, and then once warm, then switched over to fuel oil (diesel, svo, wvo, paraffin, engine oil) They will run on just about anything...

I know that hot bulb engines arent usually very fast engines, but perhaps a bit of thinking could get them to work at higher speeds.

It might be an easier method of converting an engine...

Perhaps making a large glow engine

Just more thoughts...

[Sphere]

And if you really want to go mad (might be a project for someone to try on a small diesel) there is the Coffman engine starter (and variants) which use a blank shotgun cartridge to force the piston to move down quickly, while also creating a lot of heat...

That sounds like just the thing I need for my Hatz 1B40

[Oer Al]

What about the Ural/Dnepr boxer engines? They have roller bearings - or can be easily upgraded to them, cast iron cylinders, pushrods and a relatively easy spot to add an injection pump - extend the camshaft or drive it off the timing gear. The crankshaft is weak so that would have to be replaced but a quick look at eg. Ural-Zentrale shows they already sell upgraded crankshafts, rods and pistons for these engines. Those things are made specially for these engines. They could also make a strengthened crankshaft for diesel conversions...

The crankcase might not be strong enough though. Something would have to be done about that without having to sand-cast a whole new crankcase - might as well cast a whole new engine...

[Oer Al]

Its sort of too do with the compression.

The more you compress a gas, the harder and faster it tries to uncompress, thus the pressures increase.

Now the other thing I forgot to mention is the Semi-diesel, or Hotbulb engine.
Now bear with me here...

They normally had compression ratios as around 3:1

...

It might be an easier method of converting an engine...

Perhaps making a large glow engine

Just more thoughts...

Meh, that would give even worse fuel efficiency than current petrol engines... Diesels get a big part of their efficiency from the high compression ratio. Take that away and all you're left with is an engine which will run on anything oily - nice but not really worth the effort since a high-compression diesel also knows that trick...

[IgorVigor]

Hot bulb engines were quite efficient...

and as for converting to a petrol to diesel:

http://www.dieselbike.net/privateconver ... onsI-R.htm
and scroll to Norton ES2

might have to find an old briggs engine
and see if I can convert that to diesel

[Oer Al]

Specific fuel consumption for hot bulb - and similar other low-compression - engines is much worse than that of high-compression engines. It is true that a 'big' hot bulb engine does not use that much fuel is you compare it to the size of the engine. What is also true is that those engines are not particularly powerful. Take a look at the power plant in the Lanz Bulldog, one of the better known hot bulb engines. The original version had a displacement of 6.3 l and produced a shocking 12 hp which was upped to 10.9 l/54 hp in later versions. This Allen engine fills a room at 70 hp. They can run on just about anything that will burn but they are not as efficient as high-compression diesels which can run at up to ~54%, close to the theoretical maximum thermal efficiency. Hot bulb engines run at about 12% efficiency for the lowest-compression (1:3) versions. They were gradually developed to use higher compression ratios accompanied by later fuel injection moments to avoid premature ignition. Once the compression ratio had risen high enough the temperature of the compressed air was sufficient to achieve self ignition. These developments eventually led to the indirect injection compression ignition engine, now also called 'diesel' engine because it can run on the same fuel as the direct injection compression ignition engine based on Rudolf Diesel's design. There are yet even more variations on the 'diesel' theme like the spraying/vaporizing cup injection engine designed by Jan Brons.

[IgorVigor]

I know all about the advantages/disadvantages of the hot bulb engines...

I was simply stating that the idea is there...

and hp is only a single measure of an engines usefulness...

torque is a more useful factor, and the old hot bulb engines offer a lot of torque...

what I was trying to say about the hot bulb engine though, is that a hybrid hot bulb/diesel engine should be easy to produce using a petrol engine...

not altering the compression ratio from the petrol engines standard 8~10:1 compression ratio.
instead of a sparkplug, a hot bulb style device and a basic injection system to inject the fuel.
the low compression ratio and less violent combustion ratio would decrease the efficiency compared to the true diesel, but the ability to run on anything oily with ease would counteract the loss in efficiency...

diesels will in theory run on anything a hotbulb will, but they are a lot harder to get to do so.
the hotbulb allows fuels that wont reliably work in a diesel to work quite happily...

and it should be a much simpler easier engine to modify a petrol to at home in a basic workshop...

[Oer Al]

Well, modern direct injection diesels have a compression ratio which is not even that much higher than high-performance petrol engines - 1:17 vs 1:12. That part of the idea of converting a spark ignition engine to a hot bulb / self ignition engine would not be that hard to achieve. The question is though whether there will be much of an efficiency gain to create such an engine while still remaining within the structural limits of the spark ignition base engine. If compression gets high enough to achieve self ignition - and as said that point is easily reached, probably around 1:15 - the fuel injection timing needs to be close to TDC as not to suffer performance loss caused by premature ignition. What you have created will be a lower compression diesel engine, with more or less all diesel engine characteristics. Combustion needs to be fast enough to achieve near total combustion before the exhaust valve opens or the engine will smoke like an old overloaded diesel (think accelerating old truck). This means you either end up with an engine with a low maximum speed - like the old hot bulb engines - or... well, probably a broken crank or connecting rod as the fast self ignited combustion process creates higher stresses than a spark ignited combustion with its slower flame front...

[IgorVigor]

I know what you mean, but the hot bulb engine doesn't use compression ignition, it uses a red/white hot element to start ignition.

if you kept the compression ratio closer to a lower performance petrol (8~9:1 compression ratio) then the spark ignition engine design on which it would be based, wouldn't have to suffer the gruelling, aggressive high compression ignition cycle of a diesel engine.

and as for the injection timing, hot bulb engines inject it during the intake cycle not when the air inside the cylinder is compressed.

and some hot bulb engines had a spark plug and vibrator style coil, allowing the engine to be started on petrol, and then once hot switched over to being a hot bulb engine.

a petrol engines crank should be more than capable of dealing with the stresses of combustion that occur within a hot bulb engine.
in theory as long as the fuel oil and air both occur on the intake stroke, it will run.

[coachgeo]

are not hot bulb engines not that efficient so you would be loosing a large part of why going diesel. MPG's

[Oer Al]

The 1897 Leon Bollee inverted trike used a hot bulb engine... 800 cc, 4 stroke single cylinder. To brake you move the rear wheel against the brake block... The 1896 Hildebrand & Wolfmüller seems to be based around a hot bulb engine as well. The rear wheel does double duty as flywheel.

[Dieselmuppet]

I think to convert a bike engine to a diesel, I think you would need to work out the best bike to do it on.
Something that originally revved to 10~15k rpm probably wont be a good option.

I reckon an old Honda Goldwing, or similar. Engines that only rev to say 7k rpm as petrol.

As for the converting petrol bike engine to diesel ,the thing is, sleeving the cylinder with a thicker sleeve than the stock petrol (you would lose some cc, but increase cylinder strength)
Head gasket, I would change to a solid copper one (stronger, more pressure resistant)

Might have to play with this myself

I have to agree with the use of a goldwing engine as it has a number of requirements already built in and had I not come across this thread I would have been asking the very same question as I ride an 1100 trike which I want to convert to diesel, but I want to keep it fairly standard looking. As standard as extra wheels and bodywork will allow.
Phil.

[smokyjoe]

This would be an interesting exercise, but it would take on the pursuit of a one-man R&D team. If you are pursuing just a diesel bike to ride it would be a daunting and probably frustrating exercise. If you like to tinker and "show them that it could be done", then it would be a fun pastime.

Here are some thoughts in my opinion:

The roller bearings in my old Hatz diesel of 433cc 7 HP (all roller crank and rod big end) are twice the size in diameter and width of those in my Harley 1200 of maybe 60HP. The crank case is more than twice as thick with heavy stiffening around the main bearings, head stud bosses, and engine mounts. The flywheel is much heavier in the Diesel, and the connecting rod, although about half the length of the Harley rod, is twice as thick and the big end bearing is as wide as both of the Harley rods (jointed at big end). The pistons contain a bowl-type combustion chamber on the Diesel, and are at least twice as heavy as the Harley's. On average, everything is twice as heavy as the Harley engine, but for 1/8 of the horsepower at half the RPM.

From my understanding, the VW Diesels were originally designed jointly and concurrently with their watercooled gasoline engines. It was a big project with a whole new family of engines in mind. It was designed as a modular engine (modular engine meaning that the engines utilized common parts for their respective gas or diesel designs, in other words all gas engines within the family would use a common piston, etc) that could be produced in 4, 5, or 6 cylinders, gas or diesel, and could be fitted into a common chassis for any of the 3 engine configurations. It was not a dieselized gas engine in any respect. Both the gas and Diesel blocks used similar component placements, but that is where the similarities ended. Somewhere on the web is a really interesting translated text describing the development of the VW A1 and A2 watercooled engines, written by the VW engineers themselves. Unfortunately when my old hard drive died, so did my link to the page and I've been unable to find it since. The VW Diesel block and forged crank CAN be adapted quite easily to the gas head as done by some VW Autocrossers and Enduro folks, but not vice-versa.

1978-80's GM "dieselized" gas engines used Oldsmobile big-bore V6 and V8 block designs that were cored for smaller bores and beefed up main bearing bosses. They suffered Most everything was purpose designed for the Diesel, but they had to fit the mounts of their gas counterparts. Their main drawback was a cast nodular iron crank (instead of forged), weak head bolts (since they had to fit the engine profile of the gas engines), and a lousy Roosa Master injection pump that only lasted about 50 to 60,000 miles. The biggest problem was that the average American was not ready for a Diesel. People running gasoline in them (at the time Diesel was not so available in the US, and in many areas only at those big, intimidating truck stops along the interstates), drivers who would start them cold and just "floor it and take off" before the engine was warm, people using the wrong oil, and I forgot... no water seperator in the fuel system! All of these spelled disaster. I had a 1978 Chevy Diesel pickup with the infamous 350 Diesel, with careful use (and a water seperator) I only got 60,000 miles from the inj. pump and 108,000 miles before the crank broke at the flywheel flange. (Believe it or not, it still ran VERY roughly for about a minute before it completely self-destructed) When I worked in the auto industry with GM in the late 80's, I had lunch with a Diesel design engineer from GMC who worked on the Diesel project from the beginning of their "Diesel push" around 1975. He told me of all their failures, including their failed arguments with the pencil-pushers who nixed the idea of using a forged crank and adding a water seperator. Those were interesting times. Even the little Chevy Chevette Diesel, which used an Isuzu engine and the Lincoln Continental which used a BMW Diesel were not without their problems due to ignorant drivers using wrong oil, gasoline, etc. etc.

Well, I've added my five shillings worth.................. I'd rather be designing engine mounts, exhausts and primary drives than futzing around with swirl chambers, rod designs, injection patterns, balancing, etc. Problem is if you fail anywhere along the line designing your own engine, which you would really be doing with a conversion from gas, parts will blow and you will be back to square one and out buying another gas engine to break something else on.

[Sphere]

Converting a petrol engine to diesel seems like a lot of fun... in a Big Brother kind of way

[AppRenticE]

Well a year after last comment in this thread here's something interesting from an SAE paper. Though converted to burn diesel it isn't of usual process but a combination of spark & compression ignition. Looks like base engine was 2 stroke with ~5:1 CR.

from http://papers.sae.org/2003-01-0053/ :

In this work an existing petrol engine (Villiers engine) was modified to run as a spark assisted diesel engine at an increased compression ratio. To increase the compression ratio a new cylinder head with a swirl chamber was designed and incorporated to ensure better turbulence and atomization of the fuel. The compression ratio was thus increased from 5.22 to 9.4. The original spark plug of Villiers engine was retained. To further aid the ignition of diesel a glow plug was introduced. Provisions were made for incorporating a fuel pump assembly, which get its drive from the engine crankshaft. An injector was set up in the cylinder head and was placed such that the fuel impinges on the glow plug surface. The redesigned engine, a spark assisted diesel engine, was studied in detail for its performance.

2 stroke international's engine uses very similar or same technique. http://www.2si.com/215_MF_Diesel_spec.htm

Also is http://www.sonexresearch.com/2-Stroke.htm

Probably such engines performance isn't attractive(?) or engines are of limit applications(?) for any mainstream manufacturer to cash in, else there must have been a lot in the market. However, if the technique works it'll be a triumph for the home diesel bike bodger who now is forced to use industrial engines.

[pietenpol2002]

2 stroke international's engine uses very similar or same technique. http://www.2si.com/215_MF_Diesel_spec.htm

You'll note at the bottom of their page that they are still owned by some remnant of the old Cuyuna snowmobile manufacturer. It's the old 215 Cuyuna that powered snowmobiles back in the day and then early ultralight aircraft. And now to tap into the military purse (think Hayes), it's been pimped over to burn heavy oil. At least they've recouped their tooling costs.

[AppRenticE]

... It's the old 215 Cuyuna that powered ...

yeah i missed, there's possibility of pimped up internals. I wonder what compression ratio it might be running since rest specs looks interesting apart from fact that its a 2 stroker. In theory if atomizing (here by injection), vaporizing (by glowplug till engine is warm) & ignition (by spark) are taken care of the fuel should burn clean. But in practice what all issues can be expected from the engines built by 2st intn'l or Sonex? Will it be worthy to attempt a low compression-fuel injected-spark ingnited-single cylinder petrol to diesel conversion for a dieselbike application?

[R85/8]

Very interesting thread, worth another resurrection. I just asked this question on a bike forum and got much the same answers.

The magnitude of the forces on the diesel seem to be one of the big problems structurally (the other getting it to work ).

Looking at the structural side: some bike engines can be got in various capacities, eg BMW, HD and use common crankcases for different capacities.

HD can give you a 1200cc or a 883cc on the same crankcases, BMW can give you 475cc or 980cc on the same crankcases (different cranks). So working on the smaller capacity basis, would it be likely that a bottom end capable of handling 50% or 100% more capacity on a petrol engine would be strong enough to handle diesel pressures in the smaller capacity?

[Blunt Eversmoke]

Combustion pressure for petrol is 30-60 bar, for diesel 60-90 bar, depending on CR, so theoretically, it should be manageable. Now if someone said what the peak pressures are and whether there are any combustion pressure calculators online...

[Blunt Eversmoke]

Found some formulas for both mean and peak CP. Looky here. [mode=GF]gugumimi[/mode=GF]

[Blunt Eversmoke]

To resurrect an old thread...

There is an article "Last Oiling" in the 9/1994 issue of Oldtimermarkt by the German motor journalist legend (or so http://classic.dieselkrad.info/dieselmo ... dhatz.html say; for the complete article in German with an advertisement picture of the Albertus engine, go to "mehr Bilder" right under the bike picture) Ernst "Klacks" Leverkus; a Zündapp to Hatz conversion is discussed there. More intriguingly, tho', is the following:

"Diesel motorcycles? Germany had'em, too. Four firms tried from 1922 to 1925, and now, there are two of'em on the road again - this time with starter cranks.

First, briefly of diesel bikes in Germany and Great Britain (which I shall omit since it is the Norton diesel bikes already on this site): Albertus-Motoren-Werk Richard Schulz in Königsberg, and Albertus Fahrzeugwerke AG in Achern 1922-1924; Almora Motor & Fahrzeug AG in Kassel 1924-1925; Bafag (Badische Albert-Fahrzeugwerke AG) in Achern 1922-1924; Deloma Kraftfahrzeugwerke in Magdeburg 1924. These four firms were all connected in some form, most importantly, they all used exclusively Albertus crude oil engines with

157 ccm (9.58 cu in) and 1,5 PS (roughly 1,55 hp) at 2500 RPM

or

212 ccm (12.94 cu in) and 3 PS (roughly 3,03 hp) at 2200 RPM,

constructed by the engineer Julius Loewy from Königsberg and patented at Deutsches Patentamt under the number 391786. These were three-channel (transfer, inlet, exhaust) two strokers, using decompressor for starting and gasoline and spark plug for warming up glow plates in the combustion chamber before switching over to diesel. Fuel was carbureted via a needle regulated nozzle in the transfer channel so there was no fuel inside the crankcase; nor was there a throttle. In the combustion chamber of the unitary cylinder/cylinder head piece (Sackzylinder in German motorist lingo), the carbureted diesel oil ignited by the combined effect of 9:1 compression and glow plates. To keep the cast iron cylinder cool, an aluminium jacket with massive cooling fins was situated over the cylinder's upper part.

The engines' power was quite on par with light motorcycle engines of the time - smaller engine having enough torque to diesel bike and rider up the mountain at Solitude Mountain Race (at Schloss Solitude in Hessen) along the 7 kilometers of the road in 9.18 minutes - amounting to average velocity of 46.65 kph.
Toni Bauhofer's Megola, for comparison, made it there in 4:29,4 minutes, averaging 93 kmp - but that was with the Megola's 750 ccm divided among five cylinders!"



To sum it up: Not bad at all, and even if not true diesels but carbureted hot bulbs (injection implementation missing): With combined ignition of glowing body and a relatively high compression, reasonable MPG should be achievable even without injection since no stochiometric ratio need to be kept.
Especially, if the compression part is upped to 10:1 or 11:1, and fuel is pre-heated at either the cylinder head or the exhaust manifold - or both, ensuring a more complete burn.
Pre-heating would also make for finer dispersion and lower the ignition delay of the diesel fuel and thus net higher possible RPM, but might necessitate slight throttling to retard ignition at lower RPM. Most importantly, without an injection pump to take care of, one could run waste motor oil or waste veg oil with but crude filtering - if the base engine is cheap and easy enough to rebuild.

Oil for lubrication would still have to be carbureted in at crankcase inlet or administered by some droplet oilers - if one were to keep it crankcase-scavenging two-stroke, of course. Four stroke would be harder to implement due to valves in the head which would constantly overheat; limited space in the head for a glow body would make things even harder. Compressor-scavenged (supercharged?) two stroke?..

Your thoughts?

EDIT:

@Zarquon

Maybe none survived? Three years of production makes for what, one thousand at the very most, considering that times' very many makes of light motorcycles in Germany. I'm with you on the emissions, of course - one would have to "fake" an Albertus bike of similar-looking parts, and fake markings on those parts as well to have the bike pass as antique and thus bypass emission tests here in Germany.

However, I shall try and make such an engine out of whatever junk I find in the garage just for shits and giggles - as soon as I'm done dieselizing me scooter, that is - and hereby encourage anyone with spare time and parts at hands to do it, too...

[zarquon]

I've never seen any of these "carbureted hot bulb" engines reanimated.
Maybe it is for a reason.
We had a huge rally for really historic motorcycles here in germany. Each year about 400 Pre-WW I motorcycles come together. I've seen a running Megola there and a Hildebrand und Wolfmüller as well. But no "carbureted hot bulb" or a real diesel.

It could be possible to find a historic bike/engine and make it running again. But I'm pretty sure there is no chance to achieve todays emission levels with this kind of engine.

[espe]

I wonder if you could vaporise the diesel bij using an ultrasonic element? This way you can carburete the diesel without having to deal with vaporising it by means of preheating.
In this interresting thread the name Jan Brons was mentioned. I regard him as one of the biggest accellerators in the development of commercial diesel engines. Just think about it, a carpenter living in a very small Dutch village (I live nearby it) who read some books about diesel engines and then goes on to build an engine out of the bleu which revolusionised the commercial use of diesel engines. His engines and patents being used all over the world! He and his right-hand man Dopper building the first ever recorded diesel motorbike! Leaving all the big names of the time, trying to get their vapor-sucking/blowing diesels to run properly, far behind.
For the people who are not that well informed about his invention a simple description:
In the cilinderhead a small chamber or cup is positioned. This cup is connected to the cilinder by means of very tiny holes. diesel is fed into this cup from outside by means of a low pressure pump. As the compression stoke begins, the pump pours an amount of diesel in the (preheated) cup. Because of the temperature of the cup a part of the diesel gasses up. As the piston reaches TDP the gassed diesel in the cup explodes, forcing the remaining dieselfluid into the cilinder trough the tiny holes and thus creating a fine spray of diesel which explodes as it enters the pressurized cilinder. The heat of the explosion reheats the cup so that it is ready for the next load of diesel. For years these were the most reliable and efficient diesel engines.
Then mr Bosch invented the high pressure pump and vaporiser. A lot of Brons engines were converted by mounting Bosch pumps and vaporisers on them. Jan Brons created his own high pressure pumps and vaporisers as wel, also as a conversion kit. Rumours go however that the Bosch kit added more HP to the engine than the Brons kit.
Isn't it great that a carpenter from nowhereville (appingendam) gave all the big builders the finger? Lets hope that there is a guy out there just like him who is able to create a compact lightweight dieselengine with enough HP to really get commercial dieselmotorbikes to an adult stage.

[Blunt Eversmoke]

@espe

Sey what? Would, say, a syringue needle vibrating at ultrasonic frequency make fine diesel mist?

Also, my friend, the Bronsmotor (or Hvid for those of Sam) is, ideally, even simpler than you describe: it needs no injection pump, not even a low pressure one. It sucks in the fuel into the spraycup during the intake stroke

Although, there was a Ransomes engine called Wizard, that was basically a two-stroke Brons/Hvid. That would, of course, need a fuel pump, there being no intake stroke

[espe]

Hey, Blunt.
Well I wasnt really suggesting that the needle or vaporizer should vibrate at such speeds, but it doesn't seem a bad idea. No I meant to create a fine mist in say some sort of enclosure bij means of an ultrasonic vaporizer. Next suck the mist in with the intake air. These vaporators can be found in for example those small table top decorative mini ponds or fountains in wich they create a mist.
To get back to you on the Brons motor: It maybe didn't have a low pressure dosing pump in the first few examples. But the one we own (2 cilinder) certainly has! Maybe that is because it was a ship's engine. I am curious though, since you seem to know a lot about this engine, how did they regulate the amount of diesel being sucked up by the intake stroke?

[espe]

This is one of our Brons engines. My friend owns two. I am merely helping him out restoring them and most of all disposing his beer. He's the guy in the movie, I am the one cheering and holding the camera. The engine on this film is started for the very first time in thirty years. When it came into my friends posession a year earlier it was nothing more than a pile of rust.
http://www.youtube.com/watch?v=K3g_PkQbLME