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Convert gas engine to steam??

Posted by Crazy Wayne 
Convert gas engine to steam??
November 15, 2004 10:33AM
Friends,
This is my first time here, so please help with this (probably) stupid question.
Every gas engine is basically running off of compressed gas (generates its own pressure via explosion), so why couldn't you simply yank the spark plugs and replace them with high-pressure steam lines that are controlled by the distributor to emit a short burst of high-pressure steam at the peak of the compression cycle? The high-pressure switch would be similar to that in a paint ball gun, which releases a calculated amount of compressed gas via a trigger mechanism. At the right pressure, there should be the same volume of steam exhaust as there would be normal exhaust.
Would this work? What am I missing in this equation?? Surely someone has tried this and it didn't work---why not?
Thanks,
--------Wayne
Brian Drake
Re: Convert gas engine to steam??
November 15, 2004 02:32PM
This has come up before, and I'll leave the technical explanations to the experts, suffice it to say that it won't work. A four cycle gas engine is simply too different from a steam engine for this to be a practical conversion.
Mike K.
Re: Convert gas engine to steam??
November 15, 2004 03:58PM
Asssuming you want to use an ordinary 4-cycle gas engine, you would certainly have to do something drastic to your camshaft to ensure that the intake and exhaust valves would open and close at the right times. You would have a certain amount of built-in ineffeciency because your steam would have to change directions to exit the cylinder (the piston would have to push the expanded steam out the exhaust port). Depending on the exact engine you decide to convert, you might have rust problems because of the cast iron block, pistons, and rings.
Re: Convert gas engine to steam??
November 15, 2004 04:46PM
You could probably get it to run. The idea is simular to a two stroke bash valve conversion. Several have been made that work. Using any IC engine you will have problems when the steam mixes with the deturgent oil. It will change to something like mayo. But it wont taste good on a sandwitch.

With a four stoke engine you would be wasting a stroke. A steam engine can have a power stroke per cylander every revoloution. Most get two power strokes per cylander per revoloution as they are double acting.



Post Edited (11-16-04 16:32)
Jim Crank
Re: Convert gas engine to steam??
November 16, 2004 08:23AM
Wayne,
This has been done many times, just look in the back issues of the SACA magazine, and various SAE reports. The GM SE-101 used a four cylinder block that may have been from the old Pontiac four cylinder engine.

You would need to:
1) Change the camshaft to open all the valves at BDC to use them as exhaust valves.
2) Change the camshaft gearing to one to one, or use a double lobe camshaft design. Very easy if the cam is chain driven.
3) Make some sort of oil-water dry sump system to get rid of the water in the oil. Also new pistons to take more compression rings and better oil rings. Possibly with a unaflow auxiliary port drain at BDC to try to vent water into the condenser incorporated into the piston design.
A heated sump, like the Besler Kaiser used, will work very well.
4) Keep the crankcase under condenser vacuum to remove water vapor. This has been done and it helps.

There remain some serious problems:
1) A massive heat loss into the block. Hard to insulate the cylinders against heat losses due to radiation and also conduction down into the crankcase. This is a major failing of single acting engines that don't have a separate cylinder block that is well insulated.
2) Coming up with a magnetic valve that not only will work perfectly at high pressure and temperature; but fast enough to get good admission characteristics at, say, 3000 rpm. And one that will last in service.
3) Make sure that at high pressure, there are enough head studs to keep from blowing off the cylinder head.

This certainly has been done successfully in the past.
JC
Jeremy Holmes
Re: Convert gas engine to steam??
November 16, 2004 01:04PM
Sorry, I got off on the wrong foot about this topic in the past. But I think whats being said here is pretty reasonable.

Jeremy

D K Nergaard
Re: Convert gas engine to steam??
November 17, 2004 05:25AM
Pay careful attention to Jim Crank's problem #1. Remember that IC engines are carefully designed to remove heat from the cylinder walls (lest they melt) and steam engines must be exactly the opposite if they are to have decent efficiency.
Jim Crank
Re: Convert gas engine to steam??
November 17, 2004 08:17AM
David is right, the major heat loss in such a conversion. This was a gross loss in those bash valve converted Mercury outboard engines, they had aluminum blocks. Hopeless.

Some engines in the past have sawn off the original cylinders, welded on a plate and then fabricated steam cylinders to go on top of the assembly.

One other successful conversion was to use the original cylinder block as the crosshead guides, then add on double acting cylinders. Like the Besler Chevy conversion, SE-124, for G.M. Makes for a rather tall engine, though.
Or else, use the original engine cylinders as the LP and add a single acting unaflow cylinder on top of the block. The oil contamination problem is still there, however.
All in all, it is much better to cast or fabricate a new crankcase; but use the gas engines crankshaft, oil pump and connecting rods.
JC
Mike K.
Re: Convert gas engine to steam??
November 17, 2004 03:31PM
Could you keep the block warm by running the exhausted steam through the coolant galleries?
EARL C. LEAVEY, JR.
Re: Convert gas engine to steam??
November 17, 2004 04:29PM
MIKE, IF YOU ARE BUILDING A STEAM ENGINE WITH A IC ENGINE BLOCK YOU COULD USE THE COOLANT PASSAGE WAYS FOR HEAT TRANSFER FLUID THAT WOULD STORE HEAT 500 TO 600 DEGREES . LINKS FOR TRANSFER FLUID AT THIS WEBPAGE[free.hostdepartment.com]
EARL C. LEAVEY, JR.
Re: Convert gas engine to steam??
November 17, 2004 04:50PM
MIKE, THE PREVIOUS MESSAGE WAS JUST A THOUGHT. I'M NOT A STEAM ENGINEER SO THERE COULD BE A REASON WHY THIS WOULD NOT KEPT A WARM BLOCK FOR STEAM ENGINE. MOST IC ENGINES WOULD BE DIFFERCULT FOR LAGGING AND INSULATION. EARL
Mike K.
Re: Convert gas engine to steam??
November 18, 2004 08:21AM
I suppose the biggest hurdle would be to ensure that enough steam blew through the coolant galleries that a decent flow could be maintained. In my old Chrysler 318, the coolant passages in the block were not even 3/8" in diameter, so that would have been hard to manage I think. If you used an old Volkswagen air-cooled engine as a core, you surround each cylinder with a jacket and then exhaust directly into the jacket and achieve heat transfer by condensing the exhuast steam on the fins of the cylinders and then collecting the water for re-circulation.
Ben in Maine
Re: Convert gas engine to steam??
November 18, 2004 12:41PM
Input steam to pistons =385+ ,,,,Exhaust at atmospheric is 212 unless you have superheat at the exhaust ,,,What is your cyl temp the average of ...Ben
Evan Doherty
Re: Convert gas engine to steam??
November 20, 2004 12:25AM
Hi forum
Just wondering if anyone has tried taking some of the hot gas from the boiler combustion chamber to keep the cylinders hot. Something like an Exhaust Gas Recycling Valve adapted to thermostat operation could be used to keep the block and head at, maybe slightly above steam inlet temperature.
The problems I can see with this is the water passages in the block may not be large enough to get useful gas volume for adequate heat transfer, and possibilty of corrosion of the cast iron.

Evan
Ben in Maine
Re: Convert gas engine to steam??
November 20, 2004 03:55AM
Hi ,,, The Sylvster Roper 1895 bicycle took firebox gas to a shield around the valve and cylender ,, and onto the smokebox ,,Cheers Ben
D K Nergaard
Re: Convert gas engine to steam??
November 21, 2004 06:29AM
Many of the packaged boiler/engine sets known as Lokomobiles, no relation to the car, had the engine cylinders in the breeching (flue gas plenum) of the boiler between the boiler and economiser. They showed very good fuel economies for small stram power plants.
However, they still used cylinders separate from the crossheads and crank assemblies. Otherwise, crank lubrication would not have been possible with oils of that time.
D K Nergaard
Re: Convert gas engine to steam??
November 21, 2004 04:50PM
Here's an additional thought. Assume for the moment the cylinders of an IC engine block can be heated to the point where steam efficiency is acceptable, 400-500 degrees F. MINIMUM. The crankcase will be very nearly the same temperature, the block are designed that way. What happens to the crankshaft and connecting rod bearings, which are surfaced with Babbit metal? Babbit melts at a lower temp. than soft solder!
Jeremy Holmes
Re: Convert gas engine to steam??
November 23, 2004 09:18AM
The bearing shells in IC engines are easily replaced. One could use a sliver-blend of bearing surface versa the standard antimony blends used for cheaper mass production demands. Physically the bearing shells would be identical.
Jeremy Holmes
Re: Convert gas engine to steam??
November 23, 2004 09:22AM
I mean "silver-blend"
allan
Re: Convert gas engine to steam??
December 05, 2004 10:03PM
Thay had a gas motor converted to steam on a bicycle last week on monster nation. looked like an old motorcycle motor.He said something about changing the lobs on the cam if i remember correctly.
Re: Convert gas engine to steam??
December 25, 2008 01:02PM
I converted a 4 cylinder Continental engine from a Massey Harris 102 tractor to air/steam. I removed the spark plugs, tapped the holes to 3/4"NPT and plumbed lines to a hydraulic control valve which I mounted to the front of the engine. The control valve is connected to a bolt that is about 3/4" off center on the front crankshaft pulley, by a linkage. Then I remove the lifters from the intake valves so they would not open. The pressure is the fed into the control valve forcing the outer pistons down. At BDC, the pressure is the fed from the other port of the control valve to the two inner cylinders, forcing them down while the exhausted steam (or compressed air) from the two outer cylinders is exhausted out both the control valve and one of the exhaust valves. The process is then repeated over and over. I first tried it out on compressed air, and then later hooked the engine to the boiler of a friend's steam engine via a hose. It ran very good. Someday when I get the time, I intend to install the engine back in the tractor it came out of, and build a small boiler to power it.


dave3326@yahoo.ca
Re: Convert gas engine to steam??
December 25, 2008 02:04PM
Hi Dave,

Wow, sounds like an exciting project.

"I converted a 4 cylinder Continental engine from a Massey Harris 102 tractor to air/steam. I removed the spark plugs, tapped the holes to 3/4"NPT and plumbed lines to a hydraulic control valve which I mounted to the front of the engine. The control valve is connected to a bolt that is about 3/4" off center on the front crankshaft pulley, by a linkage. Then I remove the lifters from the intake valves so they would not open.-52flathead"

Interesting name,

Most, if not all, of the IC engines that I have worked with(converted to steam) are infact 'FlatHead' engine types.

The one thing, that im concerned about, is your disabling of the intake-valve with your IC to steam conversion engine.

If by some rare happen-stance, the engine counter-rotates the engine cycle that you have created, will act as a check-valve with the piston stuck at BDC(bottom dead center), and this is what can happen if the supply pressure is high enough.
-see link/picture-



[www.steamautomobile.com]



I understand that in theory(any theory), such a condition is undesirable, even for an instant, but according to MURPHY's LAW 'what can happen- can, and eventually will'.

A good way to solve the potental problem, is to mount an additional 'safety-release-valve' on the working(piston) cylinder, were it will vent(to outside) across the top of the piston during a btc event[this is] according to my experiments, such a relief-valve, mounted on the working cylinder, can protect from a potental trapped high-pressure condition, that will be vented from the working cylinder,using such a safety valve, if the piston stall's at 'any' BDC condition, regardless of stoke scheduling.

Such a safety measure, will insure, continued experimentation. With any converted 4-cycle engine. However CV-flow rate[for the relief valve] must be matched to potental conditions for the measure to be effective.

Also, this(safety measure) is not needed if the engine has exhaust side-porting, like a common 2 stroke engine(IC).

Best

Merry Christmas To All


Jeremy
Re: Convert gas engine to steam??
December 25, 2008 03:01PM
Hi Again Dave,

" The pressure is the fed into the control valve forcing the outer pistons down. At BDC, the pressure is the fed from the other port of the control valve to the two inner cylinders, forcing them down while the exhausted steam (or compressed air) from the two outer cylinders is exhausted out both the control valve and one of the exhaust valves. The process is then repeated over and over. I first tried it out on compressed air, and then later hooked the engine to the boiler of a friend's steam engine via a hose. It ran very good. Someday when I get the time, I intend to install the engine back in the tractor it came out of, and build a small boiler to power it.-52flathead"

You need to do a little better with regards to describing your engine-flow, perhaps a schematic of working fluid flow or something.

Im assuming this, as a tandem fire, 1-4 2-3 engine, by your description. Either way, at pressures over 200psi, you should use a redundant safety release(for the hp cyl), since the high pressure cyl's are relieing on your "hydraulic control valve" to transfer psi to your compound cyl's.

In general it is most advantagious if the low psi cyl's are twice the diameter of the hp cyl's. Connected to the same crankshaft. Im certain the engine will run, from the brief description that you have outlined. Even if the displacment of hp and lp cyl's is the same.

Have you considered using only one of the 1-4 cyl's for 'high pressure' expansion? Then using both cyl's 2-3 for low pressure expansion. Just curious. Sound's like a cool project...

Best

And to all a good night



Jeremy
Re: Convert gas engine to steam??
December 28, 2008 02:58PM
Hi Jeremy:

The Intake valve was disabled to prevent steam/compressed air from escaping.

You were talking of high and low pressure cylinders. This isn't a compound cylinder engine - just 2 cylinders working together.

Dave
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