Henry Yunicks Red Hot Vapor Engine Re-Creation

Intake and exhaust manifolds:

If you look at the 300 intake and exhaust manifolds you will notice they are held up against the head with a thick washer under a bolt that straddles both manifold tabs. It is a poor arrangement and there are times when the tabs crack or break when the bolts are tightened extra to fix an exhaust or intake leak.
Since you do not want a cold intake manifold and don't care about keeping the intake and exhaust flanges isolated from each other it would be a great improvement to have both the intake and exhaust manifolds on a common thick flange with holes for studs or bolts instead of flimsy tabs.

There is a concern about having enough heat in the exhaust manifold during light engine loads.
One of the problems with a simple log manifold is only half the heat from all six cylinders would be applied to the heat exchanger tube going through the manifold by virtue of the exhaust runner locations along the log. If the turbo is at the front, all of the exhaust from cylinder 6 runs across the tube but almost none of the exhaust from cylinder 1 and varying exposure with respect to location from cylinders 2-5
Ideally all six exhaust runners enter one side of the log and exit out the other end to the turbo.
Another advantage of having longer runners between the exhaust ports and the log is a reduction in engine pumping losses and better intake port induction.
We can talk about this in length later if you want. It is also part of the cam profile conversation.
 
The 300 block deck is 10.00" high from the crank line center which is tall.
It can accommodate anywhere from a 6" to 7" long rod with a 4.00" stroke.
Rod length is a matter of application and there is no magic rod length to stroke ratio.

Lets look at the concept of using a secondary piston with a die spring or any other type of spring connection.
Lets say the secondary piston is very light at 500 grams.
At 4000 rpm at TDC during the end of the exhaust stroke, the upward force from the piston is 1600 lbs.
If the piston top is .039" from the cylinder head surface it would require a spring with a spring rate of 1600/.039 or 41,000 lbs/in just to keep the piston from hitting the head. Thats not counting half the spring weight into the equation.
As you can see, the mass of the secondary piston has relatively high inertia and detonation pressure spikes are quick enough where the piston inertia alone would still allow the piston to get damaged.

The second part of detonation is the resulting resonant pressure wave which occurs at 5.7 kHz for a 4" cylinder bore which also causes damage in the form of micro welding. We have piston rings and piston ring grooves for show and tell.

IMO A piston engine is not a good candidate for pulsed detonation operation and is better left to open chamber thrust engines.
(You made reference earlier about a pulsed detonation two stroke engine.)
 
I absolutely would love to get another perspective on routing the pipes!

Basically, the project consists of super heating the fuel under high pressure and eliminating the throttle plate. Everything else I am doing conventionally as best I can and want the best build possible. I was under the precarious presumption that temperature would more or less "equalize" in the log manifold. I was also thinking that perhaps a progressive heating of the fluid would be better. I would first heat the fuel with waste heat from the radiator, then go into the "cool" side of the exhaust on the opposite side of the turbo, and leaving the "hot" side of the exhaust just before the turbo. This way the fuel leaving the manifold was just in contact with the hottest gases and the turbo still has some heat to spool up. However, I definitely could be wrong which is why I'm consulting people like you with more wisdom and experience. However those plumbing losses do concern me. Do you think it would be better to route the exhaust going back, make a 180 degree shallow U-turn into a log with the SS line running through it there? I would think, though I could definitely be wrong, the 180 degree U-turn and extra surface area _might_ induce more drag? If I'm wrong please let me know. I probably am wrong.

The die spring idea was stupid and I chalked it up to another crazy idea that won't work in a matter of an hour. but it looks like I won't need to "extend" the block. I now realize after intensive reading that there is no magic rod/stroke ratio, HOWEVER to reduce piston sidethrust and increase dwell I'll follow Yunicks advice and run as long of a rod as I possibly can. Even if I need to get a set of custom rods made. I'll run a 4" stroke and as long of a rod as possible. If I can run a 7" rod with a 4" stroke than thats a good ratio thats a little high of average for an engine. Which is what I want. If I have to buy custom carillo rods so be it.

I had to replace my exhaust gasket and I did notice that the bolt/washer arrangement was weird and I thought kind of dumb myself. Good idea on using a monoflange for the intake/exhaust! I'll DEFINITELY be doing that, it sounds a hellova lot easier and stronger/more durable!
 
I know I said the 300 can use from a 6" to a 7" rod but that was "In General" without application considerations.

pmuller9":23ks14ij said:
The place to go to for a billet crank is Kings Crankshaft. I would specify a 2.200 rod journal instead of the stock 2.123". it opens up the complete lineup of BBC rods to choose from.

BBC rods come in 6.135", 6.385", 6.535, 6.635", 6.660", 6.700", 6.735", 6.800", 7.00" and 7.100" rod lenghts.

While decreasing side loading and increasing dwell time may be important there are other considerations such as piston parameters.
Once again here is one of my 300 pistons for a 6.8" rod.
https://www.dropbox.com/s/0a5olnskn79m1 ... 2.JPG?dl=0
Notice how the piston pin is up into the oil control ring groove where I have to use a secondary ring to bridge the gap.
Not a problem for a Naturally Aspirated engine but a piston deigned for boost has wider ring lands and I preffer to keep the piston pin out of the ring pack for long service engines.
Racing engines with frequent maintenance schedules is another thing.

That's why I was leaning towards the 6.385" long rod which is .175" longer than stock but leaves plenty of room on the piston side for generous ring lands and the ring grooves are not violated by the piston pin hole.

The other consideration is reasonably long piston skirts.
 
Makes sense. I forgot to account for the piston rings in rod length and piston skirts. Looks like I'll have to run a little on the short side with a 1.6 rod ratio and be content with that "typical" rod ratio. Its the fuel system thats special about this build anyway, not the engine itself. I just want to rebuild it for maximum reliability, durability, and efficiency. Once I'm getting over 100 MPG the truck will become an every day driver and used to haul 15 to 25 thousand pound loads up and down steep ozark gravel roads. I'll need that supreme durability and reliability of the 300 Ford! Thats why I selected the engine. It's just lacking power for what I need it for. So I'll need it boosted and I've always wanted to try the legendary vapor fuel systems. I've purchased just about every book imaginable on the topic of vapor fuel. I'm fully confidant I can get at least 500HP from a 16 PSI boosted 300 Ford running on nothing but fuel vapor and direct port water injection. Got to thinking about water injection again the other day and since my mixture is so insanely lean AND I'm controlling engine RPM via how much fuel (and NOT air) it gets, excess water/steam displacing some of the air in this insanely lean burning engine won't hurt a damn bit!
 
Water Injection:
The Hot Vapor Engine worked on the principle of stabilizing the fuel combustion by raising the cylinder tempuratures above 2600 degrees F.
If you water inject you will be lowering the cylinder temps and going back to the standard mode of keeping the cylinder temps below 1800 degrees to prevent detonation.

Both systems work.
The one problem with the Hot Vapor system is getting through the detonation zone before 2600 degrees as the engine heats up from the cold start.

Not referring to this engine project.
The one possible solution is running an ultra high compression ratio that always produces a very hot combustion chamber.
This is where the two stroke Bourke engine would work since it has no poppet valves and the compression ratio can be as high as you want.
 
I could be very wrong, but I have a few theory's. I'd rather put on direct port injection while I'm tigging it up in case I need it and shut it off if its not beneficial. However, Henry Yunick used a conventional carburetor and I suspect that he may have needed to get those temps up to fully vaporize all the longer alkanes. Longer alkanes require more heat to fully vaporize. Liquid fuels detonate much more easily because liquids propagate shockwaves much quicker than gases, which expand as the deflegration wave pushes on the gas. If a liquid droplet is consumed by a deflagration wave or it through high pressure and heat (like in an engine) auto ignites, thats when detonation occurs. To me, at least in my young and inexperienced mind, thats why he had to bring the temps up to a minimum threshold. If we're running nothing but pure vapor then logically I would think that as the temps go up the risk of detonation goes up exponentially, but with pure fuel vapor from the books I've read vaporized fuel has an equivalent octane rating of 120 to 130, depending on which source I'm looking at. Thats just my theory on why he had to get through a specific zone of detonation. Running high temps with some liquid droplets is a no-go, so he had to run even higher temps to fully vaporize the fuel.

My theory could damn well be wrong. But while I'm tigging up the manifold its far easier to put in some threaded ports on the welding table than it is under the hood. Whether or not I'll need or want it is an unknown.
 
I agree that having bosses in place so you have the option for port water injection is a smart move.

The short discussion on stabilizing combustion at high cylinder temps seemed more focused on the state of the Hydrogen atom rather than the state of the hydrocarbon fuel.
Your explanation also has good points that appear to be valid.
 
Hey really quick I want to give you a big thank you for your time and insight. This will be my last post until I get back in four months. I'll probably mock up all the externals, custom manifolds, turbo's, wires, chokes, etc. Once I prove that the fuel system is effective I'll find an old block, rebuild it, and add the same stuff, swap out the old engine and rebuild the old engine and drop it in another truck. I'll find an old truck with a bad engine and drop it in. Alternatively if its really effective I'll see if anyone here wants to buy the stuff pre-made as a sort of super turbo kit for the 300i6 since nobody to my knowledge makes a turbo kit for one.
 
Hello again and thanks for the response!
I had purchased an off road forklift for $800 for my business a few months before I left off to Ft. Leonard Wood thinking thinking all it needed was a tuneup. Well I gave it a tuneup and the engine ran, hydraulics worked well, I put it in gear and released the clutch. No power. Turns out that engine needed a rebuild with a weak 85 PSI of static compression. I took the head off the engine and sure enough the pistons were like a hot dog down a hallway! So instead of rebuilding a Ford 300i6 this summer like I wanted to I instead ended up rebuilding a Toyota 2R engine. My business was in desperate need of an off road forklift and at the time I didn't have the money to pay for a good one that was turn key ready.

Last week I purchased an old 300i6 block from a neighbor for $100 and started the teardown process however my business (rocketheater.com) is really booming and I've been short on time. Come early February I'll begin the real work of machining it and ordering all the parts and putting it back together. I've also been working a lot with Roger Richard and some other engineers on building a pulse detonation engine (a bourke engine) which is consuming a little bit of free time, and I have to finish my tire pyrolysis machine which I started on but only stopped that project because I needed a forklift to move the unit to its final resting place, a concrete pad I had poured for it a year ago thinking I would have the forklift ready for action in a few weeks (but boy was I wrong) to finish the job. Its a machine I'm rebuilding that was caught in a large fire in the 1990's that turns waste plastic and tires into synthetic diesel fuel and gasoline.

My game plan is to do a quick-n'-dirty 2k budget rebuild of the 90's 300i6 I purchased and just run it on propane for now so I can actually start using my F350 for some heavy loads for my business and once I get familiar with the engine I'll go all out on the next rebuild.
 
On the Bourke engine, What are you doing for the connecting rod to crank connection?
Is it similar to Bourke's scotch yoke?

Will this engine be fueled with liquid gasoline?
 
:D Very interesting thread.Thanks for posting.I`ll saddle up and go along for the ride.Delta V.Thanks for your service.God bless ya.
Good luck.Have fun.Be safe.
Leo
 
It will be a scotch yoke engine. Only difference is that I'm going to use a take-apart tunnel crank for massive load distribution and to allow me the use of solid one piece superposed triple slipper bearings (imagine bearings within bearings). The engine will run on propane and/or the vapor fuel coming from the thermal catalytic cracker and will have a small turbocharger on it. I'd still love to install a TCC unit plus a turbo onto a Ford 300i6 as an add-on aftermarket kit due to there not being a turbo kit for the Ford 300i6.

Later today I'll post again some pictures and video's of Roger Richard and his Bourke engine with some specs and numbers. Its the most impressive engine I've ever seen in my life.
 
So I have a question. OK maybe two.

The Bourke engine operates in detonation mode with gasoline.
Since propane has over twice the auto ignition temperature point as gasoline will it work in the Bourke engine?
The same holds true that cracked fuel vapor also has a higher auto ignition point.
Can you compensate by using a much higher compression ratio?

Most turbocharger systems create more exhaust back pressure than intake manifold pressure.
I would think that the imbalance would prevent complete exhaust gas evacuation from the cylinder.

Secondly, a turbocharger relies on the waste exhaust energy from the blow-down part of the exhaust cycle on a four stroke engine to power it.
There is very little waste exhaust energy available on a Bourke engine.

Thoughts?
 
Of course it will work. Not only will it work, you're on the right track with higher compression ratios. Now we can increase the compression ratio's to levels seldom conceived of before! I promise you 30 to one compression ratio's or higher will autodetonate and compression ignite.

As far as spark plug timing goes, because this engine can safely spool to 30k RPM and because the fuel detonates at incredible flamefront speeds we can modify a spark plug by pulling its side electrode off and eliminating all the timing mechanism's we use now. We simply install a capacitor inline to the sparkplug attached directly to a high voltage power source and when the piston comes near TDC the voltage will arc directly from the center electrode to the piston face. We can alter when the plug fires by altering the voltage, higher voltage means it will fire sooner and vice-versa. So long as it fires at or near TDC we'll be fine because all the fuel is burned before 10 ATDC and the rest of the stroke is a cryogenic cycle that scavenges heat. The scotch yoke means that the piston reaches highest velocity at 90 degree's to the crankshaft angle which greatly increases dwell.

however the spark plugs will only be there to allow the engine to fire up nice and easy. After about 3 minutes according to Roger Richard he can pull the plugs wires off and the engine continues to run as normal via homogeneous charge compression ignition.

So we have an engine here with the best of diesel and gasoline cycles, and so much more.

The Bourke Engine functions on combustion and detonation cycle principles fundamentally unlike any ICE I've ever seen. 22.5 to one average compression ratio, but the compression ratio could be variable on the fly as the engine runs due to compression ratio adjustment plug/screw. This is not to prevent detonation but rather to ensure that whatever the fuel you're using the compression ignites at the specific crank angle. Russ Bourke originally envisioned his engine as a HCSI, spark ignition. However other researchers and machinists/builders, specifically Roger Richard have made the engine with minor tweaks into an HCCI Pulse Detonation Engine. The scotch yoke mechanism ensures that the wave motion of the engine is always perfectly sinusoidal. Piston reaches maximum velocity at 90 degree's to the crank angle. The Bourke engines EGT right out of the exhaust port is around 200 F. Thats before it even goes into the exhaust manifold. This engine is about 81% efficient according to independent lab tests. However the Bourke has some flaws that need to be addressed. For one, its known for snapping crankshafts, specifically at the crank web. Roger Richard solved this problem by making his cranks from cryogenically treated CPM9V tool steel. Thats an expensive solution that isn't ideal for a production engine.
A multiple piece tunnel crank made of 4140 would be more than strong enough. Though that of course requires a slight re-engineering of most of the engine parts. The Bourke can safely spool well beyond 20k and even 30k RPM because it has no valvetrain at all. It uses slide valves on each side of the cylinder, one half for intake and the other for exhaust. Like a steam engine or if you're more familiar, more like a Detroit Diesel 2 stroke engine. Because its a PDE it has a flat torque curve similar to an electric motor. Though it would be more accurate to say it has a "variable" torque curve because torque can spike anywhere in the torque curve if you stomp the accelerator. The Bourke rule of thumb is 5.5 HP/CID on average for a naturally aspirated engine. This means that a 200 cubic inch Bourke engine would produce 1,100 horsepower naturally aspirated.

However I'd like to rebuild a Ford 300i6 with a turbo and etc. before I build a Bourke for the simple reason that I don't yet own a lathe nor have the room for one to even build an engine like the Bourke. And I want to make aftermarket turbo kits.

With my business going quite well my time has been rather strained. I have other projects I'm almost done with that I expected to be done by now but other things popped up. So I'm working hard on getting on this. I really believe I can get 200 MPG from a full size pickup truck using a Ford 300i6 coupled to a TCC unit.
 
Thanks for your reply. You helped answer a few questions about the Bourke two stroke engine operation.
I would like to have a little more discussion on this subject before moving on to the 300 six if it’s OK.
I looked at write ups and online videos by Roger Richard.
None are very recent so bear with me if I go over R & D that hasn’t been posted.

A quick summary for those looking on:
The Bourke two stroke engine operates on the detonation pulse.
The detonation pulse occurs with a sharp rise and high pressure with a very short burn period making torque development independent of rpm.
If the pulse occurs too soon BTDC the piston and crank assembly will see higher stress than normal and damage may result.
If the pulse is late and the burn process continues long after TDC then the engine looses efficiency.
The Scotch Yoke assembly with linear motion connecting rods extends the dwell time at both TDC and BDC.
At TDC it allows more time to develop cylinder pressure during detonation and at BDC there is more time for both the intake charge to transfer into the cylinder and for the exhaust to evacuate.
The exhaust port roof can then be lower in the cylinder which increases the DCR which helps with creating detonation.
In comparison, the conventional engine rotating assembly has a shorter dwell time at TDC and the dwell times at TDC and BDC are different.
When the engine is cold a spark plug is required to ignite the fuel mixture early enough to raise the cylinder pressure and temperature to the point of detonation.
After the engine is warm the ignition spark can be eliminated and the fuel mixture will auto ignite by the compression alone.

Discussion:
Different fuels have different auto ignition temperature points which would require different dynamic compression ratios in order to detonate the fuel mixture however if the compression is too high the pulse will occur too soon and if the compression is low the pulse will be late or detonation will not occur at all.
This gives a short range of compression for optimum operation for each type of fuel.

Secondly, this is a two stroke engine after all and the dynamics of airflow is the same in that the Volumetric Efficiency is not constant with rpm which means the cylinder pressure is not constant and the pulse timing cannot be optimal over a wide rpm range without some type of control.
This also means this engine should not be run with a throttle controlling airflow for the same reason.
Control should be accomplished by fuel flow only.

It would be part of the development program to install both temp and pressure transducers in the head exposed to the combustion chamber to record pulse data versus crank angle at various rpm and loads on a dyno.
Then (if needed) a control method using spark or variable compression or both can be formulated and fine tuned using the same equipment.

Again this is based on the info that I found available and if I am incorrect or there is more info that would change this discussion I look forward to it.
 
I'm totally fine with discussing the Bourke engine!

Of course the thermal catalytic cracking system we've discussed for almost a year would be coupled to the Bourke which allows the engine to run on almost any liquid fuel as whatever fuel is put into the system methane or methane like gas is produced by the TCC system. Engine RPM is controlled via needle valve, not throttle plate. Compression ratio can be adjusted via a compression adjustment screw on the side of the combustion chamber. Spark plugs could be used to make startup easier, so too could glow plugs also be used or a combination of spark/glow plugs including dual spark plugs.

If detonation timing is needed then we'd want to control it via the compression ratio adjustment plug, because as I'm sure you know its not just the ratio of compression but also the _rate_ of compression (the speed of the piston and how fast it smashes the AFR) and as RPM's increase the rate of compression increases linearly. Which means that compression ratio may have to be slightly lowered as RPM increases so that detonation occurs at TDC every time. This could be accomplished by attaching an adjustable linkage to the needle valve so that as the needle valve opens the compression adjustment plugs loosens to increase cylinder volume thus decreasing compression ratio to maintain detonation at the optimal timing. However I'm not sure if this is completely necessary because the fuel is burned so quickly whether its at TDC or close to it, I'm not sure if we'll even see a noticeable difference in performance.
 
The only reason for concern for an early pulse is parts longevity.
It would be nice to be able to verify the pulse timing versus all other variables using test equipment.
Thanks for your reply. I'm good for now.
 
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