WHY TURBINES?... Turbines actually have many good characteristics which make them ideal for creating your next Extreme Boat: they are powerful, light weight, they can use numerous fuels and they require very little maintenance (Did I mention they sound cool!).
Turbines have fewer moving parts than internal combustion engines, so that means less parts to wear or fail. Compared to high-output combustion engines producing similar horsepower (typically requiring tons of boost!), standard maintenance for turbine is trivial. And when you compare massive engine failure rates for combustion engines 9thrown connecting rods, blown pistons,...) with turbines... well you can't, turbines just humm along their marry way... massive engine failure is rare.
Turbine marine uses a Lycoming military T53 Turbine (modification 13B). These turbines consist of two rotating set of blades. The first set of blades (N1) rotates at about 19,000 rpm (this is the sound that you hear). Power is transferred to a second set of blades (N2), which then transfers power to the output shaft - and the out-drive. N2 revolves at 6,600 rpm's and generates 1450 HP. (note: Turbines have governors to limit RPM's similar to other high-performance engines).
As mentioned, the T53 turbine is light weight, weighing just 520 lbs (dry). Add in the exhaust system, starter, generator, fuel/fluids and the total weight is still only about 775 lbs. This is a 50% weight savings compared to similar output combustion engines. To top it off, the weight of the turbine is close to the bilge, lowering the center of gravity of the boat, resulting in better handling. But there's more... If you want two turbines, then the second turbine can utilize some of the systems installed for the first turbine, so the weight saving gets even better - and you end up with 3000 hp!!!
For racing applications, John says he can get more aggressive and reduce the final weight of a twin turbine setup by as much as 300-400 lbs. (For the advanced students: changing the weight drastically changes the setup of the boat, which will require adjusting, but less weight is a good problem to have!)
As you can see, turbine power has many advantages. So, we just get a special engine mount and drop it in, right? Wrong! Turbines were never designed to be put in a closed engine compartment in the back of a boat. To do the job correctly, all of the turbine's systems need to be evaluated and configured specifically for a marine application.
This is where Turbine marine excels. John and his team have gone thru each and every system in the turbine and have re-designed them for reliability and safety. The critical systems include: exhaust, lubrication, electrical, fuel, transmission and even the steering system.
When a turbine first comes into their shop, it is completely disassembled and inspected by Turbine Marine technicians (with 25 yrs of turbine maintenance and engine development experience in the Army). Every engine's internal parts are services, or replaced, and brought back to flight specifications to maximize longevity and engine life for harsh marine use.
That's the basics. We would expect this from any turbine installation, but John goes further. Corrosion is a major issue, so all painted parts are stripped down to bare metal, epoxy coated and repainted to the customer's specified color of choice (You want it to match your boat, don't you!). All external steel fasteners on the engine are replaced with stainless steel. Specialized fasteners which cannot be replaced with stainless steel are chrome-plated to maximize corrosion resistance. After the engine is hand assembled, it is run on an in-house Dyno and tuned.
But, before the turbine can be installed, John makes a number of other custom modifications to assure that the engine has a long, productive and safe life. Here's why...
Exhaust System: Problem: Turbines generate tons of heat and high velocity exhaust gasses. (Ever stood behind a jet? You get the idea...) That heat and gas must be cooled and routed away from the boat and humans, otherwise things start melting quickly. Turbine Marine has researched this problem and has designed a water-jacketed exhaust system specifically for the T53. The exhaust system is kept cool using a high volume, 24-volt electric water pump (which receives current from the turbine's generator). water pressure and exhaust temp gauges are mounted in the dash so that the status of the turbine can be monitored. The result is that there is almost no heat build up in the engine compartment as you would find in other installations.
Lubrication System: Problem: Lubrication is essential at 20,000 rpm. Turbine Marine equips the turbines with a dry-sump oiling system (w/12 qt. oil capacity). Again, the dash is outfitted with oil temperature and pressure gauges for monitoring these systems.
Electrical system: Problem: Stock T53 turbine electrical components are not designed for marine environments (or salt water). Turbine Marine has developed its own environmentally sealed digital voltage regulator and components suited for the marine environment making the electronics much more reliable.
Fuel System: Problem: As turbines wind up, they fill their main manifold with fuel. When the turbine is spun down, about 1 pint of fuel must be drained from the main fuel manifold. Some turbine installers let this fuel dump into the bilge and then assume that it gets pumped out with the water in the bilge!?!? Turbine marine installs a high performance fuel system which has a "recovery tank" to capture unused fuel for re-use; clearly a much safer approach.
Transmission: Problem: Turbines generate a lot of horsepower, which, if not monitored, can cause transmissions to fail frequently. Turbine Marine installs custom designed dry-sump gearboxes (for Racing & Poker Runs). If you so desire, they also provide custom dry-sump hydraulic transmissions with environmentally sealed micro switches built into the shifting levers. These provide flawless conventional shifting without any buttons or peddles to push. The turbine output reduction gearbox is equipped with a torque metering system which allows the driver to monitor the amount of ft./lbs. of torque the turbine is delivering to the out-drive at any given time, so that they can limit the chance of over torquing, and breaking, the drive.
Steering System: Problem: There are no fan belts on a turbine for your power steering system. Turbine Marine has developed its own electric-over-hydrolic power steering system that is powered by the turbine's generator. It automatically runs at a constant RPM which gives you a smooth, pulsation free operation at any speed. it has a built-in fan for cooling & is designed for 5,000+ hrs of operation.
As you can see from the issues outlined here, it is not a trivial task to install a turbine engine. To do it right requires that you revisit most of the internal and external systems and re-configure them for this very special application.
Turbine Marine is so confident with their approach, that they offer a 1 year (or 1000 hrs) warranty on the engines (not on drives/ gearboxes). That is amazing, and shows they are confident that they have built a reliable engine.
Speaking of hours, what are the running costs and maintenance issues for a turbine? Well, turbines have another cool feature; they can run on multiple fuels, and, on multiple fuel combinations; You can choose from Jet A, Kerosene, diesel, a mixture of diesel and unleaded gas (75% D/ 25% G Mixture), or a combination of all fuels mentioned (almost like the "Flux Capacitor" from "Back to the Future"). Jet A or Kerosene are recommended because they burn cleanly & odor free. Typical fuel consumption is a little higher for a turbine.
What about scheduled maintenance? The #1 maintenance task for a turbine is to flush the compressor after each use. To make this task simple, Turbine Marine outfits the engine with an on-the-fly engine compressor wash down system that can be utilized while you are running, to keep the engine's internals free from salt build-up on extended trips. Nice!
In salt water you need to wipe down the engine to prevent corrosion. But, John has replaced many magnesium parts with aluminum where possible, making this task easier.
As for fluids, transmissions and drives should be changed every 4 hrs of running. But engine oil only needs to be changed about every 1000 hrs!
Now, John does not do this alone, he has a team of 7 skilled staff who are knowledgeable in all aspects of boat building and turbine engines (between them they have 25 years experience in maintaining and modifying turbines for the military). John has completed 7 turbine-power installations to date, and he is ready for more...
From what we have seen, it looks like John and his team have really thought thru all of the problems that can arise when trying to fit military turbine into civilian pleasure craft. We like his solutions, and his attention to detail. So, the next time you run across a turbine engine at the military surplus store and you start to think that it would fit nicely in the old Fountain sitting in your brother's backyard - think twice. Or better yet, call John... He'll even let you choose the color!!!