HJ212 Model

350 hp / 4000-4500 rpm
210 mm / 8.26-inch impeller

Dimensions shown in the drawing are indicative only for initial design purposes. For detailed installtion data and instructions, contact HamiltonJet. All dimensions shown are in millimeters.

This is HamiltonJet’s smallest water jet. The HJ212 offers a JT nozzle as standard equipment, as well as an optional “turbo” impeller with up to 50% more grip in aerated water.

“Turbo” impeller: HamiltonJet currently offers three different “turbo” impellers designed to reduce cavitation and allow for operation in adverse water conditions: the 2.4T for 5.7L engines, the 3.4T for 6.2, and 7.4L engines and the 4.0T for 8.1L engines and 6.2SC

Common engine match: Gasoline V-8 engine. 

Typical applications: The HJ212 is designed to be used on trailerable craft operating primarily in fresh water. 

Approximate weight capacity: Single jet to 6700 lbs., twins to 13400 lbs. 

History & Design

The HJ212 was introduced in the mid 1990’s as the replacement for the aging 770 series of multi-stage jets. Design improvements on the 212 versus the 770 series include:

• Much improved pump geometry
• Considerable reduction in pump noise
• Optional turbo impellers that incorporate the efficiency of a single impeller with the anti-cavitation characteristics of a multi-stage
• A size increase of about 15% to better handle the power of today’s V8 engines
• Highly effective JT nozzle design vs. the older less effective T3 design
• Split duct reverse vs. the older clamshell type
• An optional space saving close coupling that eliminates the need for a conventional H bar driveline

The design improvements incorporated into the HJ212 resulted in a jet that would handle about 30% more load, cruise at a lower rpm, burn less fuel, reach a higher top speed, and stop and turn more effectively.

HJ212 Frequently Asked Questions

What size of boat is the HJ212 suitable for?
In North America the typical vessel is 19 to 23 feet with a single jet, up to about 30 feet with twins. Most boats with a single jet weigh approximately 3,500 to 5,500 lbs. Boats with twin 212 jets are typically 7,000 to 8,000 lbs. In both cases, some additional weight can be carried if needed.

Will the HJ212-drop right into the spot where a 773 jet was?
Unfortunately, no. The most common problem is having to move the engine ahead slightly to accommodate the larger jet. This modification can usually be done without a great deal of problem. The transom angle may also be a bit different. At a very minimum, the intake of the old jet must be removed and a new intake block welded in.

Is replacing a “pressure pump” a problem with the HJ212?
Most of the old fashion so called “pressure pumps” are smaller than the HJ212. Hence, the intake and transom holes also tend to be smaller. This makes it easy to open things up a bit and weld the 212 block into place. Of course, you have to measure things and see how they fit and line up to be certain.

Over the years since the HJ212 was introduced, lots of people have used it to replace older jets–both older HamiltonJets, as well as numerous other brands. It’s safe to say that the satisfaction rate with the HJ212 is very, very high.

What’s a Turbo impeller?
The Turbo impeller is basically a single impeller with two rows of blades, one in front of the other. Think of it as load sharing. It also increases surface area of the impeller which results in better cavitation control.

Does Hamilton offer standard impellers as well as Turbo's for the HJ212?
We do, but we almost never sell them. The Turbo accelerates better, hangs onto aerated water better and generally improves overall handling versus a conventional impeller. In short, for the minimal cost difference there is just no reason not to use the Turbo.

Do you make more than one Turbo?
There are three different ones:  The 2.4T is for the small block Chevrolet 350 and the Ford 351. The 3.4T was designed for Chevrolet 454 & 6.2L as well as the Ford 460. The 4T is intended for the Chevrolet 8.1 and SC 6.2L, but may also be used on some “built” Chevrolet 502. Chevrolet 6L may use the 2.4 or the 3.4.

What kind of full throttle rpm should I expect to get with the 212 turbo?
This will vary with the marinization and vintage of the engine, but in general, at or near sea level, we will see something close to the following rpm’s from these common engines:

Ford 351/Chevrolet 350 2.4T   4,100 - 4,200 rpm
Chevrolet 383 “Stroker”   3.4  4,000 rpm
Chevrolet 6L 2.4 4,450 - 4,500 rpm
Chevrolet 6L  3.4  3,900 - 4,100 rpm
Ford 460/Chevrolet 454    3.4T      4,000 – 4,100 rpm
Chevrolet 502   3.4T 4,200 – 4,300 rpm
Chevrolet 502     4 T  3,850 rpm
Chevrolet 8.1 375 hp 4 T 4,020 rpm
Chevrolet 6.2L   3.4 4500 rpm
Chevrolet 6.2L   3.4T 4200 rpm
Chevrolet 6.2L Supercharged 4T  4250 - 4400rpm

Most of the boats we see achieve an acceptable cruising speed at 2,800 to 3,300 rpm. However, this will vary widely with the individual boat and load.

If you’re operating at higher altitude, expect to see a significant drop in rpm’s and power. You will loose roughly 3% of your horsepower for every 1,000 feet in altitude. If you’re in that situation, you may need to use a smaller impeller than you would at sea level to achieve a reasonable rpm. Be aware when running at altitude that standard gasoline engines will lose power, simply changing the impeller will only change the rpm of the jet and engine. Generally it will not make the boat go faster. If speed is required at higher altitudes consider a larger engine or even better a Turbo charged diesel or Supercharged gasoline engine.

How is the HJ212’s fuel economy?
Boat builders that have installed HJ212 in aluminum boats, where sterndrive-powered counterparts exist, report similar fuel usage between the two versions. Because boat designs differ dramatically, it’s possible that you could get slightly better or slightly worse economy, depending on the situation. In general, a jet is more efficient on lighter, clean running vessels.

Can the 212 be used in saltwater?
Sure! Just wash it down with freshwater when you’re done. Ideally, back it into freshwater and run it for a little while. This will flush the water pick-up tube and the engine at the same time. Please note that the HJ212 isn’t designed to be moored in saltwater for extended periods. If that’s what you intend to do, you should consider the HJ213.

Can the HJ212 be run out of water?
No, not if it’s directly coupled to the engine. You’ll destroy the cutlass bearing in the tailpipe and possibly damage the water seal. Never run the jet when it’s dry.  An optional dry-run kit is available which will allow you to run the jet out of water for several minutes at low rpm.

Can diesel engines used with the HJ212?
It certainly can be done, but we would have to look at what was proposed and get the application approved to be sure that there wasn’t a problem. Diesels present some unique problems that would have to be addressed.  At a very minimum, a few changes would have to be made to the jet and a suitable torsional coupling would be needed. Beyond that, the impeller range of the HJ212 is not as extensive as that of the HJ213. A suitable impeller may not exist for all diesel engines options. That said, there are small, high rpm (3,300 to 4,100 rpm) diesels from Yanmar, Volvo, Cummins and Steyr that  could be used on some occasions. Larger, slower turning diesels, would require a larger jet. The HJ213 really is the best way to go for diesel applications

What is the difference between the HJ213 and the HJ212?
Both jets are the same size and produce the same thrust from the same horsepower.
However, the HJ212 was intended to be used primarily with gasoline engines on recreational or fresh-water guide boats. The HJ213 is the commercial version; it has more anode protection, a heavier mainshaft and thrust bearing, some different alloys and power hydraulic reverse.

Are all HJ212 jets the same?
Since the jet was introduced a number of years ago, it has undergone numerous upgrades. The jet of today is considerably different from the jet that was introduced in the mid 1990’s. Over the years, significant changes have been made to improve the balance of the Turbo impellers, increase the cooling water flow to the engine at low rpm’s.   and the nozzle design has also been greatly improved.

A word on jet model size.
With jets size counts. If you have a large boat and you hope to make the most of it you may need a jet bigger than the HJ212. It may be a HJ241 or a HJ274, perhaps even a larger jet. It depends on the size and weight of the boat and how much thrust is required to push it, it will also depend on the RPM of the engine. The lower the RPM the bigger the jet will need to be to impeller it and produce maximum thrust.

If you have questions about jets sizing, please give us a call at 800-423-3509.

Click here to download the HJ212 brochure (PDF).


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