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Repair or Replace Marine Engines, Marine Diesel Engines, Used Marine Engines, Man Marine Engines
Performance Product Technologies Question & Answer Forum
Topic: Re-powering your Boat
Question: What options do I have if I'm looking to repair or replace my existing Marine Engine?
Response: It doesn't take long when looking at the price of new boats to start investigating the alternative option of replacing or repairing your existing marine engine. This forum covers the options of marine engine longblocks versus bobtail marine engines.
Engine Rotation - No matter whether you choose a longblock or complete bobtail engine the rotation will be a very important factor to evaluate. Rotation with marine engines is always viewed from behind the engine looking towards the flywheel. Standard rotation (left hand) means the flywheel is turning counter clockwise looking at it from the rear, or another way to think of it is that the harmonic balancer will turn clockwise when standing in front of the engine looking at it. Opposite rotation engines (right hand) were common years ago however not regularly produced today as the later variety of transmissions; Hurth & Velvet Drive have negated the need for this as the gears can rotate either direction without issue.
Marine Engine Longblock - This term generally refers to the cylinder block heads as well as the required internals of the engine. Generally marine engine longblocks do not include the intake manifold, engine circulating pump, or flywheel. Depending on the brand product the "tin ware" (oil pan, valve covers, timing chain cover) may or may not be included. Much like the flywheel, since the tin ware is not considered a "wear" item some manufacturers do not include this with their marine engine longblock products.
Bobtail Marine Engine - This term generally refers to a complete new engine as required to complete a "drop-in" replacement project. Depending on the manufacturer of the product in question these products generally come complete with fuel, electrical, cooling, and exhaust systems as well as the engine mounts yielding it ready to drop right in when replacing a used up engine.
When it comes time to investigate the options there are several things to consider; first and foremost is the age and condition of the engine being replaced. If the engine itself is bad, but the exhaust and other marine engine systems are in relatively good shape it can be a good option to simply replace the marine engine longblock. However, unless you intend to complete the work yourself one must always consider the labor associated with switching the attaching hardware over from the old marine engine to the new one. Common issues that arise when replacing a marine engine longblock are whether the intake manifold will match, making sure the flywheel is correct, making certain the ignition system matches properly, and making the necessary adjustments for mechanical versus electric fuel pumps. With marine engine longblocks there are either remanufactured or brand new options with the prices actually being very close to the same for either option.
If the determination is made that the complete marine engine needs to be replaced one may want to consider a complete bobtail marine engine. When replacing a complete bobtail marine engine you will need to determine if the existing coupler can be used and if the existing sterndrive or transmission will couple directly to this. In many cases of the engine is more than 10 years old you will likely have to change out the engine harness connection plug as these have changed over the years. It is also common to have exhaust changes since the exhaust systems have changed from 3 inch to 4 inch. There are several different manufacturer options as well as even the option of changing from one to the other if it makes more economical sense.
Longblocks
Marine Power
Crusader
Mercruiser
Marine Diesel
Repair or Replace Marine Engines, Marine Diesel Engines, Used Marine Engines, Man Marine Engines
Marine Engines Specifications and Marine Diesel Engines at Performance Product Technologies
Engine Installations Guidelines: Before beginning the marine engine or long block installation please review the following instructions. Verify the root cause of the original boat engine failure. Check the engine assembly for shipping damage. Verify the engine ordered and received is correct for the application. Read all warning tags and additional information supplied with the engine. Contact Performance Product Technologies with any questions.
- The intake manifold must be thoroughly cleaned and free of all debris before being installed on the engine. Debris such as old piston/ring materials can become lodged in the intake manifold, plenum, and EGR system. This debris can and will be pulled into the new engine causing pre-mature engine failure.
- After installing the engine, rotate the crankshaft a minimum of 4 complete revolutions before engaging the starter. Nuts, bolts, washers or other small parts that may have been dropped in the intake can severely damage the replacement engine. If the engine cannot be rotated by hand, inspect for foreign objects in the combustion chamber.
- The oil pump must be primed and the entire oiling system must be purged of air before the drive belts are installed and the engine is started. The preferred method is to use a pressurized system to push clean oil through the entire system. However distributor type engine's can be primed with a priming tool and a hand drill to rotate the oil pump drive shaft. Oil must flow to the top of the engine to the rocker arms. Another method before the spark plugs and drive belts are installed can be used. Disable the fuel and ignition systems. Crank engine in short durations until oil pressure is achieved. Then an additional 2 minutes in short durations to insure the oiling system is purged of air. Never re-use existing oil coolers and/or oil lines. Check and adjust oil level after priming and purging is complete.
- Installer must diagnose, repair and insure proper operation of engine related systems and sub-systems. Failure to make repairs to these components may result in engine failure.
- The installer must verify that the proper gauges (oil pressure & coolant temperature) are functioning properly. The manufacturers will not cover warranty on products that experience oil starvation and overheat since it is required to have the engine protected by these gauges and the associated alarm systems.
Warranty Claims
- For warranty related questions, as your selling dealer please direct all initial contact to Performance Product Technologies. We will assist you at this point to coordinate assistance. Please make sure and follow these guidelines before calling;
- Have your invoice number available
- Have your engine serial number available
- Date of and Engine hours at time of installation
- Current engine hour reading
- Make, model, year, and hull I.D. of your boat.
- Description of the problem that you are experiencing.
- It should be noted that Performance Product Technologies is not the manufacturer of the new or remanufactured long blocks. Therefore the warranty is thus provided through the manufacturer. You can read our warranty policies and procedures by selecting the following link Policies.
