Livorsi’s Raw Water Flow Gauge Might Just Be the Added Protection Your Engine Needs

For most boaters, the engine is the single most expensive component of every boat. And, if you’re a high performance type, the size of that investment escalates exponentially in direct proportion to the amount of horsepower under your engine hatch. In simple English, if you break it, it’s probably going to be expensive.

So why take a chance? If you could add just one more safeguard that would give you a warning before trouble resulted, it seems like a prudent idea to do it. At least that’s what Livorsi Marine is counting on when they released their Raw Water Flow System.

Gauges that measure the internal water pressure of raw water cooled engines are quite common, both for inboard and outboard powered applications. And for the most part, water pressure gauges do a good job of measuring the pounds per square inch of water pressure inside the cooling passages of engines, intercoolers, exhaust headers, sea strainers, etc. What they don’t do, however, is tell you anything about the amount of water flow (or volume) that is moving through the cooling system which is quite different than pressure, but every bit as important to the longevity of an engine.

Livorsi president, Mike Livorsi commented, “With the growing popularity of ventilated step-bottoms and various types of air entrapment hull designs, maintaining adequate water flow to the engine has become a more critical issue. What a lot of boaters don’t understand is that it is entirely possible to see normal water pressure readings indicating that everything seems to be okay, but the engine or other related components are actually starving for enough water to properly perform the cooling function.”

This dilemma became evident as the result of Livorsi’s sister company, CMI, the leading marine manufacturer of high performance water-jacketed stainless steel headers for over two decades. Some customers using CMI headers were reporting that the stainless steel tubing was becoming excessively hot when in use and in a few extreme cases beginning to turn the steel into an unattractive shade of blue which is a certain sign of high material temperatures. After investigating the source, it became evident that the problem was not with the headers, but by a lack of water flow caused elsewhere in the cooling system. What was puzzling was the fact that onboard water pressure gauges did not indicate abnormal operating conditions, or that a pressure problem existed. Instead, the culprit was a lack of flow volume, not pressure, which can result from a number of factors but are not always detectable by a standard water pressure gauge. “Once we knew what the problem was, it was simply a matter of engineering a reliable gauge that would accurately measure water flow at all engine speeds from idle to wide open throttle to let boaters know there is a cooling issue needing attention,” said Livorsi.

The system, which is patented, consists of a miniature paddle-wheel and a brass fitting which mounts in-line on the output side of a sea strainer or sea pump. In order to know if water flow and volume deviate from normal levels, the Livorsi Raw Water System is initially calibrated both at idle and wide open throttle. Once those readings are locked into the system, the gauge is then ready to trigger an alarm if in the event water flow rises or falls more than 20% from the established normal operating range. If the built-in LED warning light illuminates, it is an immediate signal to the boat operator to shut-down and check the cooling system for debris, a kinked hose, worn impeller or any other issue that might be restricting water flow to the engine.

What’s an added benefit to those who enjoy simple do-it-yourself projects, installing a Livorsi Raw Water System is relatively easy. The gauge is a standard 2-5/8” size and is available in 12 or 24 volt versions. Electrical hook-up requires only a couple of wires. The all important paddle-wheel sensor installs inside the in-line bronze Tee fitting. All you really need to know is what size hose when ordering (1”, 1.25”, 1.5” or 2” I.D. is available.

If it takes you more than an hour to do the installation you’re probably taking too many beer breaks. Here’s an easy step-by-step guide to follow.
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The Livorsi Raw Water Flow gauge takes a standard 2-5/8” hole for helm installation. You either have the choice of cutting a new hole, or if you want to exchange it for an existing gauge or accessory (like a clock, depth finder, etc.) that works too. Notice that all necessary wires, tubing, fittings and clamps are included with the gauge kit.

This "brain" panel should be mounted in a relatively easily accessible place near the helm (close to the fuse panel is recommended). All it requires is three electrical connections (positive, ground and running lights) and the ability to access the controller on the module in order to set the normal flow volume at idle and full throttle. You only need to set the system once and it automatically remembers what the normal flow rate is. If flow deviates by more than 20% (high or low) from the established pre-set flow, the gauge will no longer read in the ‘safe’ range and an audio warning will sound

The brass Tee fitting incorporates an internal paddle-wheel mechanism which measures the rate of flow at all engine RPMs. The Tee fitting is available in four sizes from 1-inch to 2-inch to accommodate different diameter water hoses used on various engine models.

For most accurate readings, the Tee fitting should be inserted after the water pump and before cooling water enters a heat exchanger, headers or the engine. If possible, try to find a section of hose where the water hose is straight rather than making an abrupt bend or angle.

The 1.25” water hose has been cut and one end of the Tee fitting has been secured with a clamp. The Tee fitting takes up minimal space and does not require the relocation of any other accessory or component.

With the Tee fitting completely installed and the electrical sensor on the paddle-wheel connected, the gauge is ready to test.

All that’s left to do is head to the water and set the flow parameters at idle and wide open throttle. Remember, excessive heat is a major contributor to engine failure. If the cooling system is starving for water, you need to know about it long before it does serious damage.