Ed Higginson finds that a full engine replacement is a very viable alternative to major repair

In our modern throwaway society, reconditioning of automotive parts has become less common. Not too many decades ago you would normally send away brake shoes or clutch plates to be relined, starter motors to be rewound or engines, transmissions and diff housings to be rebuilt, all with the objective of  extending their service so you could get a second and third life out of them.

Times have certainly changed, as its now often cheaper and quicker to buy some components new, especially with the push towards new genuine parts by the major OEMs. But while the mainstream service technicians may no longer often practice the art of rebuilding, versus replacement, there is one sector of the industry that is growing strongly, with HM GEM engine replacement maintaining its leading position for over 50 years.

As others have reduced in size, HM GEM Engines has grown and diversified. With its head office in Melbourne and 10 facilities spread across Australia, the company employs over 120 staff, providing professional engine reconditioning and cylinder block machining services, as well as crankshaft, camshaft and cylinder head servicing.

Using the latest remanufacturing, cleaning and testing equipment, HM GEM can work on any brand of motor from 3 litres to 95-litres, together with camshafts and anything from a small two-stroke engine block up to a 78-litre diesel.

The business originally serviced only the automotive industry, starting with Ford and Holden. But today its profile has expanded into agriculture, earthmoving, marine, mining, power generation, and heavy vehicles.

Bruce Parker is the owner of HM GEM Engines and began with four friends 50 years ago in a business known as Head Mod which focused on cars. With Bruce’s experience as a motor mechanic, he formed HM GEM Engines around 30 years ago and soon began expanding into heavy equipment.

Starting as a motor mechanic back in the days when engine reconditioning was part of all apprenticeship training, this background experience helped Bruce start the business which has subsequently become much more specialised.

Today there are three main business divisions within the company, with the remanufacturing of 4×4 and passenger car engines, the supply of cylinder head change over along with new units and the machining services that works across various industries.

On the day PowerTorque visited the main manufacturing facility in Dandenong Victoria, HM GEM Engines’ General Manager, Dean Taylor was on-hand to show us around the state-of-the-art factory. His 23 years of experience was clearly in evidence as he was able to point to various engine parts at different stages of the process and identify their brand, cubic capacity and probable fault at issue without hesitation.

“We are able to recondition any engine from small cars, to trucks up to major mining equipment,” said Dean. “We can work on any brand, we just need the machining specs from the manufacture or customer to know its tolerances,” he added.

With major engine manufacturers amongst their customers, such as Caterpillar, Cummins, MTU Detroit, Komatsu, Mack, Scania and Volvo, HM GEM Engines has also developed a very strong reputation within the heavy-duty diesel industry.

HM GEM Engines works with many of the dealers and fleet owners in circumstances where they have themselves pulled an engine apart after failure and then sent the components to HM GEM for testing and machining work before reassembling the engines for its second life.

“After a full inspection which can include non-destructive crack testing of engine blocks, cranks, rods and cylinder heads, we will then write up a scope of works. Most failures can be repaired including stitching blocks back together if a rod has come through the side. It all depends on where the issues are and the associated costs of repair,” said Dean.

“We are also able to rebuild engines for individuals. As we receive an old engine, our team can quickly dismantle it, chemically clean the components and then inspect them to ensure they can be reused.

“Core components that can be reused include cylinder heads, crankshafts, camshafts, connecting rods, oil pumps, rockers, valve covers and oil pans. Items such as pistons, rings, bearing shells, timing components, valves, lifters, gaskets, and seals will then be replaced with new parts.

“We are commonly asked which engine is the most reliable, but to be honest the only ones we see have been neglected and blown up. If you keep up with the correct servicing, use good oils and run it to specification, they’d all last a long time.

“Back when I started as an apprentice 23 years ago, we would be working on 80-100 engines a day. Now, with the increase in costs, GST adding 10 percent and the banks preferring to lend money on new vehicles rather than a rebuilt engine, that side of the business has reduced to between 5-10 a day.

“All our locations have stock of remanufactured engines and cylinder heads available for sale, and as engines have become increasingly larger and more complex, the machining services side of the business has increased. Our locations are close to our major OEM customers around the country, including Cairns, Townsville, Brisbane, Coffs, Sydney, Tamworth, Wagga, Shepperton, Adelaide and Melbourne.

“External workshops can strip and assemble the engines but then outsource their machining due to the specialist work and tooling required. We have the largest fleet of Rottler tooling machines in Australia and with engines getting larger, the need for reconditioning them has increased significantly,” Dean explained.

With the introduction of new generation of engines to meet the stricter emission standards, HM GEM Engines has continued to invest heavily with over $10 million in state-of-the-art facilities.

“The new engines have brought some challenges, so we have introduced Ultrasonic cleaning for the inlet manifolds and inlet runners as we get a lot of tar build up in the new engines that is hard to get out with traditional cleaning processes. We also see DPF filters coming in now for Ultrasonic cleaning, which is a new market with Euro5 and Euro6 engines,” said Dean.

HM GEM engines has a long list of processes on offer, including cylinder block milling, counter-bore recess machining, liner seat insertion and cam follower bore insertion. They can also perform cylinder block main tunnel machining if they do not meet reusability guidelines.

After the machining process is complete, all cylinder blocks are then subjected to a final quality inspection and rinse to remove excess machining residue. The cam bush, gallery plugs, and welsh plugs will then be fitted if requested by the customer, before the machined surfaces are finished in preparation for shipping.

When it comes to the reconditioning of crankshafts HM GEM Engines can work with components up to 4,000 mm in length with a 300 mm stroke. The crankshafts are firstly subjected to a rigorous inspection and crack-testing which includes non-destructive magnetic particle crack-testing, Rockwell hardness testing and crankshaft bend checking, before examining all journal radii for sizing, taper, and ovality.

“The future is certainly going to grow in the heavy vehicle side of things, plus we see a growth in cylinder heads in the market with new components which will take the place of the old change over core deposit system. It can get messy with deposits and the changeover of cores so that can be a barrier for some customers,” added Dean.

For added peace of mind, HM GEM Engines provides a 12-month, unlimited kilometre Australia-wide warranty to match that of the suppliers of new parts. This is a strong indication of the quality of engineering available from the company and its high reputation and standing within the industry.


  1. I knew Bruce Parker when he was at Doncaster. Is he still with us. My name is Kevin Jackson and i worked with him for a short period. I originally came from Head Hunters and Repco Industrial Parts Clayton who i worked with Les Dunne, Doug Tomilson and others.

    Kind Regards


  2. Thank You……

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