The "Buck" engine

Buck engine

All I can say is .28 was the indicated value. The link Using BSFC #'s indicates this is possible in small 4 stroke high speed diesels. Not to belabor the point but I was always taught that indicated readings are not necessarily actual readings. This is why I said that the .28 was an indicated value and not an actual value.

How many 5 liter 4 cylinder engines have you seen that make 340 horsepower@ 2800RPM. Maybe those numbers are fantasy as well. How many guys in a small shop have you seen build a diesel engine from scratch.

Actual dynamometer readings.

Buck engine

If I assume that persons posting here have actually read the previous post, is that assuming too much? I thought that post 33 was plain enough that I have actually tested engines on the dynamometer. For me, in testing engines, all numbers are indicated values until the results have been reproduced numerous times and in different test cells. One test cell run does not an actual, publishable result make.

Buck engine

It really doesn't matter if we are talking indicated or actual, the .28 is possible and your argument is that it isn't. It may not be possible with most designs but what I have here isn't like most designs. If technical is what you are looking for then try this.

Every engine in service (other than the large ship engines) today, cools by circulating coolant from the front of the engine to the back, in the engine block around the cylinders and then returning the coolant through the cylinder heads back to the front of the engine (there may be a few small intermittent holes from the block up to the cylinder head along the way). I have seen a couple of engines that are reversed but they are still front to back and back to front. In this form of cooling the rear cylinders operate at higher temperatures than the front cylinders and the cooling is less than optimal. Temperature stacking and hot spots are a problem. I think you should agree that as power is increased that every engine reaches a point at which it can no longer cool itself. I think you will also agree that the higher the heat, with the same amount of fuel, the higher the efficiency and that the same amount of fuel can be burned at different efficiency levels. Compression ratios effect efficiency as well as fuel combustion timing. If you increase the compression ratio you increase efficiency as well as increase the heat. If you inject the fuel earlier in the cycle, combustion takes place sooner and the cylinder pressure goes higher and the heat goes up. If you increase the boost pressure the cylinder pressure goes higher and the heat goes up. In the end if you want to increase the engine efficiency you must increase the amount of heat with the same amount of fuel.

With the increased heat you must increase the cooling efficiency of the engine or the engine will melt down from all that increased fuel efficiency and higher temperatures. That is where the Buck design moves to the head of the class. Instead of front to back series cylinder cooling the Buck design uses individual parallel cooling. The last cylinder in line receives the same temperature coolant as the first cylinder. The cooling path for each cylinder is less than 20 inches whereas a conventional engine cooling path might be 8 or 10 feet or more. Aluminum transfers heat at 4 times the rate of iron so with the Buck cylinder heads and cylinder jugs, being made from aluminum, the radiant heat transfer is far superior to the heavy cast iron engine parts. Engine oil that moves through the cylinder head and jug is also cooled to a greater degree. The cylinders on the Buck engine do not touch each other (1/4 inch or more gap) so there is no heat transfer from one cylinder to another. The upper block of the final design is aluminum so oil and coolant cooling is also increased. The oil pans are aluminum with heat sink designs. The Buck engine uses a very high efficiency after cooler as well so that higher boosting is possible. Compressed air temperatures of 350+ degrees F are reduced to intake raw water temperature (equal to the temperature of the water the boat is operating in. The idea is that you can only increase the power and efficiency if you can increase the cooling. The first consideration for the Buck design was the cooling efficiency of the engine. I feel confident that the Buck design cools better than anything currently produced.

With better cooling the Buck design can increase the compression ratio to 18 to 1. With better cooling the boost pressure can be increased to 50 PSI. And with better cooling the power density level can be increased.

One last thing that may effect the fuel efficiency, to a considerable degree. We expect to operate the engines by reading the dynamic cylinder pressure of each cylinder and using that data to adjust fuel delivery to each cylinder in order to balance all of the cylinder peak pressures. If 1500 psi per cylinder is required in order to maintain a selected RPM, then each and every cylinder will be making 1500 psi. This will maintain an even load on the rotating assembly parts and reduce wear. It also has the potential to increase fuel efficiency. No this has not been tested but it is possible today with existing technology.

In the end the Buck design has the potential to be the lightest, most compact, highest power density and most fuel efficient engine ever offered to the marine market. It should be able to do this while maintaining good durability. None of this is strange or off the wall. It is for the most part just taking advantage of starting from scratch with a totally new engine architecture and not being anchored to doing the same thing that has been done for the past 100 years.

Buck engine

Buck engine

I thought that new engine design and development was within the scope of your rules. I am not selling anything, only discussing design benefits and research and development. I apologize if I crossed the line.