History

My first exhaust system.
My first exhaust system was designed in 1987 as an external system transom mounted chamber that spanned the beam of boat. The design object was to reduce exhaust noise and to direct exhaust fumes away from the boat. The design was quite effective. The overall decibel level on the boat went from over 100dB (A) to under 80 and the exhaust fumes were carried away with the prop wash. There were no performance benefits to this system and as such there wasn't any fuel savings, like that which we have experienced with today's systems. This design was stepped of the hull about 12" and the exhaust opening was not underwater. This system was marketed under the name Delta Aero-Flow. The system worked well but the size of the system made tooling extremely costly.

The next step, 1990
In 1990 I was asked to design and build a new 66' Motor Yacht. In the design of this new yacht I took the exhaust to the next logical progression. It was a transom mounted design but I removed baffles that were used in my first design. In addition, smaller secondary chambers on the outboard wings of the system were implemented to reduce noise from the by-pass exhaust. In designing the hull I placed at the rear of the chamber, the opening was placed 1" off the hull bottom. With this application the vessel was less than 70 dB (A) thought the entire rpm range. Exhaust fumes were carried away from the boat while underway. The two slots placed in hull did two things: First It sped up the flow of the water though the slot and also seemed to help steerage.

The Marlin System, 1994.
In 1994 the system was refined yet again. It was still a transom mounted system that doubled as small platform, but this time around the system was designed specifically for the sport fish market. I called it the Marlin System. A great deal of time and effort went into the development of high speed lifting wings to give the vessel higher back down speeds. The system was installed on a 38' Black fin and a 70' Tolly Craft. The system was very quiet, under 70dB (A), and it did a good job of redirecting most of the fumes away from the boat. Backpressure was around 20" of water. Back down were fast, providing rear lift in a sea way. Very fast and dry.

The Lifting wing of the marlin System.
This is the final design of the wing. The Marlin system generated a great deal of interest but due to very high tooling costs the project was dropped. More testing was done in later years on this project and the system was designed and installed aboard more than 30 boats all of which had incredible back down performance.

The first inside system, 1995.
In 1995 I designed the first small inside system for a new 36' Durado under the name Neptune Marine. The objective of this project was to see if an internal system could be as quiet as the big full-beam external system and if it could manage backpressure as well. I wasn't happy with the backpressure. It was just less than 40" of water.
The system was as quiet as the big units, though, and the fumes were successfully redirected away from the boat. It had a cruise of 40 knots.

Our First Underwater Exhaust, 1995.
Shorty after the launch of the Dorado 36', I understood that a small chamber could be as quiet as a big chamber but I needed to approach the backpressure issue. A system was design aboard a 43' Aventi Motor Yacht the boat was powered with a pair of high output 3208 cats and she was a real smoker. On our first sea trial there was heavy black smoke from 1500 rpm to WOT. The exhaust pipe was undersized - only 5", the boat should have had 8". The objective was to design a system that would pull a vacuum to overcome the inadequacies of the existing exhaust pipe. The system did just that by pulling a vacuum of 12" bellow 0. The engines ran absolutely clean, no more black smoke. This project gave birth to the first underwater vacuum system.

The First Underwater Exhaust System, 1997.
In 1997, after testing the 43' Aventi Motor Yacht deal of time went into model testing of various exhaust openings. The objective here was performance; sound was no longer an issue given that all of the systems to date had been so quiet. The above design was installed on three SEA Ray Hulls - two 34' and one 37'.
All three boats had one thing in common; they were getting on plane in about half the time. Exhaust backpressure was measured at close to 0 on the 34's and the 37 footer pulled 17" bellow 0.

Project X-3000, 1998.
News of Neptune’s successful installation on the three SEA RAYs done in Tarpon Springs started to get around. I designed five other systems aboard a 46' Hatteras, 38' Albin, 26' Shamrock, and a 43' Jersey. The fifth boat was referred by and a long time supporter Tim Chalfant, NA and Marine Engineer, he was the Chief Engineer for Bertram Yachts at the time. He sent me a problem boat, a new 43' Bertram with excessive exhaust noise and a smoke problem. The system resolved this issue and Tim is still a valued supporter. Shorty after Boston Whaler Showed an interest in the design. Keath Ranieri and scott Woods went for a ride on of my 34' Sea Rays fitted with this new system, they were so impressed with the performance of the system that they implemented the system on their first inboard in decades - the 34' Defiance. The system subsequently became standard equipment on the boat at the insistance of their dealers.

The Defiance 34'.1998.
The outcome of this project was very important for both Boston Whalers as well as for Von'Widman Designs. The design would prove much as to performance of a tunnel hull design. The design object was to bring exhaust noise below ambient water noise and to redirect exhaust fumes away from the boat, but the primary objective for me was hull performance, getting on plane to cruising speed and top end. The final objective was to achieve as low backpressure as possible. The design exceeded all objectives, planning more than twice as quickly than without the system. Exhaust backpressure at cruise was amere 0.75'' of water. His only real problem with this design was still the high cost of part.

The Hull inserts 1997.
The EPS 1000 Exhaust & Performance system was first introduced to the marine industry as a hull insert at the 1999 IBEX show in Fort Lauderdale. The objective was to design an exhaust system that would meet the need s of the next generation boat builder by providing a system that solves exhaust noise and backpressure related issues. Equally as important, was to simultaneously save the builder time and money. The EPS 1000 has number extraordinary advantages over and above that of conventional exhaust systems. For the fiberglass boat builder, our exhaust chamber was designed as an integral part of the boat through the implementation of a male mold insert in the hull mold. The EPS 1000 Chamber was made as a part of the hull during the lay-up process, saving time and money for the builder. Since the system is competitively priced with other exhaust system, the savings are derived from its easy installation.

Our first application. Doc/MTU 2000 series Engine
Our first application on a DDc/MTU series 2000 engine convinced us that we were doing more for hull efficiency. The project was for a 60' Bertram, Blue Heaven, powered with a pair of new 1350 hp DDC MTU 2000 Engines. We implemented our patented adjustable wedge allowing us to adjust our fixed angle wedge laterally while the boat is underway. The wedge was set at a1\4'' deep at the start of the initial sea trial for the system. To establish the fixed wedge depth, the system is optimizing for cruise,@2150 rpm in this case.
The system was with in Detroit’s specifications with the 1/4'' wedge, 34’’h20 (DDC/MTU has since changed the backpressure spec to 21''h20).while at cruise, backpressure and speed are recorded as the wedge is lowered by 1/8'' increments. With each turn the boat went faster, fuel flow rates remained the same and backpressure came down. When we reached 15''h2o the mechanic for Detroit said that he could here change in the tone of engines, like they were not laboring as much. At zero backpressure, and fuel flow rates still unchanged, the cruise of the boat had increased just over two knots. The sea trial on the 60' Betram was significant because we did not experience any improvement in engines or torque efficiency. All of the previous application to date had resulted to an improvement. The difference was that the DDC/MTUs are equipped with waste gates and a sophisticated fuel delivery system. In spite of that fact, we improved the speed of the boat by over two knots. The only reasonable explanation was that the system improved the efficiency of hull with the thrust of the exhaust.

The Keel Pipe, 2001.
On Rivolta Marine's new 38 Jetsetter there simply was not enough room to run round pipes to the transom. This same concept was presented to hatteras two year earlier. Rivolta took a chance; the exhaust ran 6' along the keel, at the same height of the center stringers. The generator was mounted on top of the exhaust run. There was no hull vibration and the system was a quiet as our other systems. Backpressure was well within engine manufacture's specifications. Workable space is always in short supply on any motor boat; the additional space that the keel pipe can provided is its primary benefit. The keel pipe all but completely eliminates the need for conventional round pipe. Who knows, some day it may be considered the only way to build and design a motor boat? If you have to get the exhaust out of the boat you may as well do it taking up as little room as possible and at the same time use the exhaust for something other than a lot of hot air.

The thrust idea is put to the big test.
Shortly after I designed the rivolta 38'Broward marine was the first big boat company with the foresight to realize the advantage of this new design. But this time we were designing an exhaust run almost 30'long. The proposed design included an engine room dump chamber located on the outboard side of each engine. The exhaust dumps in from overhead in to chamber, at low speed and idle exhaust is accelerated out the port and starboard sides of the boat from secondary exhaust by-pass chamber within the dump chamber. The exhaust run from the engines room to the rear exhaust thrust chambers was very direct with a minimal number of bends. The exhaust duct design was 10''x 20'' and a by-pass pipe of 5''.the rectangular pipe design is about 22% more efficient at moving gas and water than a round pipe system. The next phase in the development of this system is to maximize the exhaust flow rate through the exhaust thrust thrust flap.

Adjustable wedge.
the design of the adjustable wedge we very important as to understanding hoe to dial-in backpressure at any given speed range of the vessel and understanding the hull pressures on the wedge as it related to speed and sea state. The is the first wedge system that has the capability of adjusting backpressure on the engine system while underway.
This tool was very important in the design and development of the wedge system. We use today on most of our applications. The real value of this design in the future is aboard large displacement vessels. The system can be installed as a full time adjustable system so that the exhaust pressure can be adjusted to any sea state and speed at the time. The system can be tied in to the engine logic boards so adjustments can be done by computer. Automatic adjustments keep engines running at maximum efficiency.

Today: The IEHS
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