Engine Rebuilding

Engine Rebuilding Services

Engines in an industrial setting take a lot of wear and tear. Regular maintenance and proper use can lengthen the life cycle of an engine – however no amount of oil changes and services can delay the inevitable, and eventually your industrial engine will reach the end of its tether. So, what do you do in this case? Well, one option is to buy a new engine, but it is hellishly expensive on average. Another option is to buy a second-hand engine, but that has its own associated risks as you cannot be sure of the kind of treatment it received in the hands of the previous owner.

Here at Eagleharm Engineering, we can meet your specific set of needs with an industrial engine rebuild. Our investment in CNC technology ensures we have one of the fastest turnaround times in KZN. We can accommodate an entire engine overhaul, or narrow it down to an engine block overhaul, or an engine block resleeve. We can even focus on just a cylinder head overhaul.  An industrial engine rebuild will further extend the life of your industrial engine and it will function better than ever before with new parts, cleaned systems and a tuned up timing!

When Do I Need An Engine Rebuild?

If you notice that there is a loss of compression, excessive oil consumption, or excessive oil clearances then it may be time for an engine rebuild.

You could have a compression loss if you are noticing any of the following:

  • Your engine requires extended cranking (it is hard to start),
  • Your engine has a lack of power or
  • Your engine has a regular misfire (it is running rough).

All of the above symptoms can be caused by a lack of compression. However, they can also be caused by other things. So, before the engine is rebuilt it should be diagnosed by performing a compression or leak down test.

If you have to keep adding oil to your industrial engine, but there are no visible external leaks, this is known as excessive oil consumption. Oil consumption can be caused by:

  • Worn valve guides,
  • Dried valve guide seals,
  • Stuck oil control rings, or
  • Excessive cylinder to piston clearance.

Oil consumption could also be caused by a faulty PCV valve, which is very inexpensive to fix. Try replacing your PCV valves and gaskets before deciding to rebuild the engine, as it is a much cheaper option.

The most common symptom of excessive oil clearances is a knocking sound coming from the engine. A less common symptom of excessive oil clearance is low oil pressure. Engine knock can be caused by:

  • Worn rod bearings,
  • Main bearings,
  • Piston pins,
  • Pistons, and
  • Cam bearings.

Sometimes some types of engine knock can be repaired with the engine. However, the engine must be partially disassembled to know for sure.

If your industrial engine is exhibiting any of these symptoms, get an expert to take a look at it. It might be time for an industrial engine rebuild.

The Industrial Engine Rebuild Process

After consigning an industrial engine rebuild, it goes through a number of steps in the rebuild process. With every step, each component and the workmanship involved are carefully appraised to ensure only the best gets delivered to our clients. The steps are detailed as follows:

  • The Dismantling Process
    In any industrial engine rebuild, there are many components that need to be cleaned and possibly replaced or machined. The easiest way to appraise all the pieces is to completely dismantle the pieces of the engine. Once the engine has been dismantled; all the pieces can be properly cleaned and inspected.
  • The Ultrasonic Clean
    After the engine has been completely taken apart, each component is placed in the ultrasonic cleaner for up to 45 minutes until completely clean. An Ultrasonic cleaner is a specialised piece of equipment that uses both a chemical solvent and high-frequency sound waves to completely remove the oil, grease and any other dirt or debris off of the engine parts. Once completely cleaned, each individual piece is inspected by a technical professional.
  • Bearing Clearances
    After a complete disassembly, it is of the utmost importance that the engine fits back together perfectly. One of the most crucial fits is that around a bearing, as this is a moving part that could fail catastrophically if not properly inspected. Qualified artisans perform all the necessary inspections and ensure that each part matches the manufacturer’s factory specifications. If the part fails the inspection, the part is machined to the next oversize or undersize (according to the part specifications). Should the part be damaged beyond repair it is thrown away and replaced.
  • The Assembly Process
    After every individual part has come out of the Ultrasonic Cleaner, and the qualified artisans have performed their inspection and given the go-ahead, the engine can then begin to be re-assembled.

The parts are checked once more as they are put into place, and the entire engine is rebuilt according to the manufacturer’s standards, ready to be given back to you and put back to work.

The Break-In Period

While more common in car engines, industrial engines function off the same principles and as such, also have a break-in time. Much like a car engine, the same rules apply:

  • Try to vary the load on the engine,
  • Do not exceed 75% of the throttle,
  • Do not exceed 75% of the RPM,
  • Do not use synthetic oil, and
  • Do not let the engine idle for extended periods of time.

Pros & Cons Of An Engine Rebuild

Much like anything in life, you can’t have your cake and eat it.  While an engine rebuild has many advantages over other options (such as buying a new or second-hand engine) there are certain drawbacks. The pros and cons of an industrial engine rebuild are:

Pros +


A rebuilt engine is typically cheaper than a new one, and more cost-effective in the long run than a second-hand engine, as it is not as likely to have mechanical issues.


A rebuilt engine has had all its components checked. New components have been brought in to replace the damaged ones and every part is in line with the manufacturer’s specifications. A second-hand engine may have had non-standard repairs done to it which could fail and break, meaning a rebuilt engine is a more reliable purchase.

Carbon Footprint

Buying a new engine results in throwing away the old one. This leads to waste, engine parts taking up space in landfills, and oil, grease and other unsavoury fluids leaking and possibly contaminating ground water supplies. An engine rebuild is giving your current industrial engine a second lease on life and is reducing the amount of waste contributed.  An industrial engine rebuild is an eco-friendly choice.

Increased Economy and Horsepower

A rebuilt engine is essentially identical in performance to the engine when it was still brand-new, so you can expect better performance out of it than a second-hand engine of the same type.

Cons –


Rebuilds take time. Often 2 weeks or more for a full engine rebuild. A new or second-hand engine will be available almost immediately.

Find Out What Caused The Failure Of The Engine

While an industrial engine is a self-contained complex system on its own, it is connected to a larger system which it feeds and from which it receives feedback. If the engine failed due to some cause down the line, it will fail again in the same way if the cause is not identified and rectified. For instance:

  • If the engine overheated, ensure that the cooling system is checked.
  • If the maintenance was spotty, the site manager needs to be stricter.

There is usually a correctable reason for engine failure (barring a few unexplained phenomena). If the reasons for the engine failure is not identified and addressed, the engine will repeatedly fail.