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Quotes - Engineering - SalesHigh Output Marine Blocks
D28 inline six, V8 and V12
MAN marine engines run from around five hundred horsepower to well over two thousand, and the cooling reflects it. The D28 family inline sixes broadly cover the lower and middle of that band, the V8 blocks sit above them and the V12 blocks reach the top. At these ratings jacket water, charge air and lube oil are all substantial duties and each one is sized against its own figure from the engine data sheet.
These installations are typically fast motor yachts, patrol craft, pilot boats and high speed commercial hulls, which means high load fractions, short raw water runs and generous pump capacity. That combination pushes tube side velocity to the top of the acceptable band for copper-nickel before anyone chooses a frame, so the pass arrangement gets deliberate attention on every MAN selection we quote.
The build is our standard marine set: copper-nickel or titanium tubes carrying seawater on the tube side, coolant or oil on the shell side, bronze bonnets and brass tubesheet with replaceable zinc anodes. Metric connections are normal on these engines and adapters are listed on the quotation. Send the engine designation, rated output and rated speed with the old unit dimensions to Sales@HeatX.com.
High Output
Velocity Limits
Parallel Units
Titanium Option
Quoting a MAN Replacement
At these ratings we need the hydraulics alongside the heat, and the space alongside both.
Duty Inputs
- Engine designation and rated output
- Rated RPM and duty rating class
- Jacket water, charge air and oil rejection
- Raw water pump capacity and pipe run
- Available length and mounting positions
What We Supply
- Large HC frames in marine build
- Parallel and split duty arrangements
- Copper-nickel or titanium tubes
- Bronze bonnets with zinc anodes
- Adapters for metric connections
Duty Profile
- High speed planing and patrol hulls
- High load fraction at cruise
- Warm coastal and Mediterranean water
- Packed engine room layouts
| MODEL / RATING | HORSEPOWER | DUTY | TYPICAL SELECTION |
| D28 inline six, lower ratings | About 500 to 730 hp | Jacket water and lube oil | HC Series with CN tubes |
| D28 inline six, higher ratings | About 730 to 1,000 hp | Jacket water, oil, charge air | HC Series plus lube oil cooler |
| V8 blocks | About 1,000 to 1,200 hp | Jacket water, oil, charge air | HC Series large frame |
| V12 blocks | About 1,200 to 2,000 hp | Split jacket water duty | Parallel HC Series units, call for rating |
| Older V8, V10 and V12 | Call for rating | Package cooler replacement | AB Series or HC Series |
Erosion at High Flow
Reading the failed bundle
A bundle that has failed by erosion looks nothing like one that has failed by corrosion. Erosion grooves and thins the first few inches of tube at the inlet, leaving the rest of the tube in good order. Corrosion pits and perforates more evenly, and often under deposits. On MAN installations the first pattern is far more common than the second.
That distinction changes the replacement. An identical bundle into the same shell at the same flow will fail the same way in the same time. The answer is a pass arrangement that drops velocity, a larger frame that does the same for a given flow, or titanium tubes where the flow cannot be changed. Photograph the failed inlet tubesheet before it is scrapped.
V12 ratings and parallel layouts
Our jacket water selection runs to roughly 1,250 horsepower on the largest two pass frame, and a good number of MAN V12 ratings sit above it. Those duties are handled with two units in parallel or a split arrangement across separate circuits, and both are normal rather than exceptional at this end of the market.
Parallel units need balanced piping. Symmetrical headers and equal branch lengths keep both shells doing equal work, whereas a convenient tee loads one and starves the other. Tell us the space you have and we will propose a layout that balances, including which end the connections should face.
Related
ENGINES • OTHER MARINE
MTU Coolers
The other high output European family and its arrangements
+ Learn More
APPLICATIONS • JACKET WATER
HC Series
Frames from 614 to 1772 and where their capacity ends
+ Learn More
APPLICATIONS • ENGINE COOLING
Jacket Water
How the engine coolant loop and the seawater side interact
+ Learn MoreCommon FAQs
At the lower V12 ratings sometimes, at the higher ones no. Our jacket water selection reaches roughly 1,250 horsepower on the largest two pass frame, so above that we quote parallel units or a split duty across circuits. Send the rejection figure for your rating and we will set out the options.
Because velocity is highest where the water turns into the tubes, and any grit in it works on the same few inches. High capacity pumps and short pipe runs make that common on MAN installations. An identical replacement repeats the failure, so we change the pass arrangement, the frame size or the tube material.
Broadly around 500 horsepower on the smaller inline sixes to over 2,000 on the V12 blocks, depending on the block and the duty rating class. Work from the designation and rating on your engine, because the jacket water, charge air and lube oil rejection are published against that specific rating.
It is worth pricing. Warm seawater cuts the available temperature difference and speeds up fouling, and where velocity is also high the copper-nickel margin narrows. Titanium is an option code on the shell and tube frames we select from, and because a titanium build is rated against its own duty we will price it with a rating rather than a catalogue figure.
Yes, that is routine on these engines. Measure shell diameter, length between bonnet faces, connection sizes and thread form, and mounting centres, then photograph both ends with a rule in frame. With the engine rating alongside we match a current frame to the duty and the envelope.
