In theory it is possible, but not very practical on account of different compression ratios etc.

But can u tell me why?? which is the major bottle neck

The different compression ratios imply that the cylinders would be different dimensions. Also, the different pressures could result in engine imbalances.

A more important "why" is why would anyone want to do such a thing in the first place.

All cylinders could be the same volume and dimensions. Just change the volume of the head volumes a little bit to raise the compression ratio.

As far as the OPs question yes it could be done but it would serve no real purpose or overall gains.

There is a six-stroke-cycle engine concept, if that helps.

• The first four strokes are internal combustion. The fifth stroke sees water injected into the hot cylinder and the sixth stroke sees it ejected as steam with further power obtained. The strokes are suck/squeeze/bang/blow/squirt/chuff.

Engine cooling systems are much simplified in principle. However, it wouldn't work in Antarctica because of the enhanced Coriolis Effect at those latitudes...

The strokes are suck/squeeze/bang/blow/squirt/chuff
Now you've made me splarf on my keyboard.
Del

Do you have any logical reason for asking such bizaar questions?

bizaar bizarre

Who are you, my Spelling teacher?

That idea sounds like a formula for "the world's roughest running engine."

I'm having an "operational difficulty with you.

OK, how's this?

Sure, it can be done. No problem at all.

Go ahead and do it.

Send pictures.

Nice one! Definintely worthy of GA.

I have better titles in mind, but I'm sure you can imagine what they might be.

Something to do with the shallowness of the gene pool comes to mind.

The mind boggles...

Are you trying to tell us that that gene pool needs more chlorine.

_{^{That one does.}}

Hi Doorman, "Shirt of Bacon", brilliant. I'll be adding that to my list of argument winning comebacks.

If you are determined to have 2 engines, 1 running on petrol and 1 on diesel - why not do exactly that - 2 separate engines. I'm sure there are ways of combining their (different) outputs. Better still, 1 could idle while the other delivers power. But to combine them in the same block, with different compression ratios, fuel injection requirements, ignition timing, optimum rotation speeds, power output and different vibration characteristics, etc. seems to be the height of folly.

There have been engines that are started on petrol (8-carbon molecules) and swap over to paraffin (12-carbon molecues) once running. They are a bit 1973 these days. Does that help?

It goes way further back than 1973!

The first international diesel tractors were gas start/diesel run back in the 1930's and a few people made modifications to them so that they could run continuously as a dual source fuel tractors.

By modifying the gasoline starting intake and carburetor systems, normally just used for the gas starting mode, the engines gasoline power mode was able to have its power raised up considerably to the point it was close to the normal diesel run mode power.

By doing so the engines could effectively run on either gasoline or its early variants or diesel fuel and its early variants.

Those International engines were supposed to start and run on petrol for a short while only before switching over to diesel and the engine must be stopped in diesel mode.

If not the valve that opens the small chamber warps and if it leaks, the engine will not run on diesel because of compression leak and then the head must come off to repair the valves.

I worked on some of the last ones that was still used here in WP South Africa.

Juriesa

A friend bought one, and his father in law, who was a WWII Merchant Mariner, said these war babies came out due to fuel rationing. It had two tanks, one for petrol, one for diesel or kerosene, whatever was available.

The tractor was started on petrol, and once the block was heated up, it was switched over to the other fuel for the day's plowing.

He told us that it had to be switched back to petrol before stopping the engine, so that petrol would be in the float bowl for the next start. The engine would not start on anything but petrol.

I accidentally put diesel in a petrol truck once. It smoked awfully, and would not idle, but it ran enough to get me back to the station where I drained the tank and put petrol back into it. It was hard to restart, but after a while it was ok.

Mike, The petrol/kerosene engines had to be stopped on petrol.....or if accidently stopped on kerosene one had to drain the float chamber and have it filled with petrol before starting again if cooled down.

On the other hand, the petrol/diesel internationals had to be stopped on diesel...because the small combustion-chamber valve would warp if hot and left open as in petrol mode.

The reason for this complicated design was to get the heavy engine started with the old 6volt starting system.

Yes, I've heard about such incidents, eventhough I think that many gas filler holes don't take a diesel spout.

Do you imagine taking the wife shopping on one of those? it's half a dozen parkings at least: " Hold on honey, let me switch back to... uh.. the other fuel".

What's a spout??

What a great photo. So many of us take modern conveniences for granted. I can just imagine the trouble this station has closing up each night, setting up each morning, dealing with thieves and robbers.

One bad spark and the whole business blows up. Some idiot drives up smoking a cigarette.....

Yes however as any good farmer knows whats supposed to be done and what can be done with a bit of creative tinkering are two different things.

I heard about it some years ago around the antique shows as a old friend of one of my friends was reminiscing about what they had back on the farm in his younger years. Apparently according to him his dad and uncle modified one of their tractors to run on what ever fuel they could afford or was the cheapest which was sometimes diesel or kerosene and other timed gasoline or light distillates as he called it.

Supposedly that old tractor ran both ways for quite a number of years modified that way without any problems!

We had a old WD9 that did the gas start diesel run thing and I recall it having diesel pump problems once and I ended up driving it about 10 miles on the gas start system. Drive a half a mile and fill the 1 gallon start tank then drive another half mile and fill it again.

It never seemed like it hurt the old thing doing it but it was pretty weak running on just the fixed flow carb and burned a lot of gas while doing it but I can see where if it was modified to have a normal carburetor and jetting system plus maybe a bit more compression while in the gas start mode I can see where those old engines could have run that way rather well!

The point is (I don't really have one) but I know that hanging around old farmers at antique shows and picking their brains always brings out some interesting information, education, and past history on what can be done when you absolutely have no other choice at the time.

http://en.wikipedia.org/wiki/Hesselman_engine

Military used a "universal" fuel engine in the 2 1/2 and I think the also the 5 ton trucks.

IIRC it was called Hercules and ran on any liquid that burned. Never tried it on anything other than "mogas". That was the story though.

Thanks and here we have discussed about the limitations of the engine can somebody tell me what would be the advantage of this engine.

At least I thought that you would be able to tell us what your vision was. I mean, what are you on about? You come here asking completely obnoxious questions and then ask what it could be good for. Give me a break and try, study what has been suggested.

Advantages? I can only see complications and unnecessary trouble all the way.

I want one just to drive the EPA pinheads nuts on how to test it!

I might even add a propane fogger to as well and a turbo just to really get their undies bunched up tight!

No advantages whatsoever. Which is sort-of-why they are so uncommon.

If you ran out of diesel then the gasoline cylinders would still work and vice versa.

Bigger fuel tank of either has to be easier.

Recently I read that Wartsila has made a 4000hp engine(most efficient engine made so far) which operates by a mixture of diesel/gasoline,for marine transport.

can you share me the link or furhter details about the engine

When I come across it I will inform

www.wartsila.com is the site

If you wish to do this project start with a diesel engine for the diesel strength requirements. Lower the compression on the gasoline cylinders with dished pistons. You may be able to use or modify the injector ports for spark plugs. compression for gas should not exceed 10:1. with available fuel. You will need a system for spark for the gas. You will have to divide the intake manifold between the two systems as one runs on vacuum and the other unrestricted. Add a carburetor or fuel injection and head for the local car meet to show off your creation.. May be a lot of fun..

You are correct, I neglected to add an air limiting device to the plan. And another thing, you will need to synchronize the two speed control systems to work together.

So you have a 2 cylinder engine running on one fuel dragging the other two cylinders as dead weight. It doesn't sound very efficient. Or do you have 2 fuel systems?

I want to use two fuels at same time

Why?

Try looking Googling.... Somander Singh Grooved Piston Engine.... On flat or slightly crowned four cylinder engines, he has made the engine run on anything that burns and has enough torque for no gears..... That is his claim anyway. Posted from my wristwatch.

Two words..... Multifuel engine..... The U.S. Army had em in trucks for a long time.....

Two words: Read the OP.

In a 4 cylider Engine... First 2 Cylinder should operate in Petrol fuel and next 2 cylinder should operate in Diesel.

While your're at it, add propane as another fuel. You can use a 6 cylinder engine; 2 cylinders per ruel.

Oh WOW, I vould have had a V8.

Just let the 7&8 cylenders run on hydrogen. As long as we are this far on the "what if" road, we might as well throw this in also.

It is possible but??? You have a crank shaft with throws at 180degree. front and rear cylinder can run on one fuel and center cylinders can run on the other for mechanical balance. There may be some vibration due to the difference in power stroke. The big issue will be isolating the intake manifold since gas runs on partial vacuum due to throttle body valves and diesel is open and controlled by fuel volume. I suggest as before you start with a diesel for strength and add the gasoline components. Good luck

The flat "boxer" type engines that had cylinders opposed would make the intake issue easier, but are there any diesels of this design?