Rubber parts blog

What is an Engine Mount and How Does it Work?

Engine mounts are one of the most important parts in a vehicle or industrial equipment. They can be...

Engine mounts are one of the most important parts in a vehicle or industrial equipment. They can be found in airplanes, cars, trains, boats, trucks, buses, tractors and any other vehicle or equipment that uses a motor or engine. Have you ever thought about what keeps your engine in place in your vehicle? The answer is engine mounts. These small parts are imperative to the proper and safe function of any moving machine. 

Continue reading to learn more about engine mounts and how they work.

Importance of Engine Mounts

conical mounts_EMIf you put a fragile item into a box and shake it around, it will probably become damaged. The item may even damage the box itself. However, if you secure the fragile item using rods and cushions to hold it in place, it will stay still when the box is shaken. Engine mounts work in the exact same way. 

Here are some of the benefits of using good quality, rubber mounts:

  • Reduce excess engine vibration and noise
  • Keep engines from sustaining damage
  • Extend the lifespan of the engine and connected sensor components
  • Keep transmission and other vital parts from sustaining damage

Engine mounts are designed to absorb the energy of the system and become worn out after a while and may require an engine mount replacement. It’s important not to wait to replace your engine mount or your vehicle may be damaged.

Access The Complete Engine Mount Design Guide

Engine mounts are essential to the proper functioning of any motorized vehicle. With our free resource we'll help you understand everything you need to know about custom engine mounts.


Engine Mount Form

Engine mounts can be of various designs or form depending on the application and amount of energy they need to absorb.  Because of this, most mounts are relatively small or just large enough dampen and absorb the energy without taking up too much space. There are a few parts that go into an engine mount. One of these is the molded rubber bushing or mount which acts as the vibration control and cushion. The engine will typically be attached directly to this part. There will also be a bolt that goes through the length of the motor mount, which is used to secure it.  The purpose is to make sure there is a rubber break between the two mating surfaces. Some motor mounts have a metal cover over the rubber part to provide more stability.

Engine mounts are made in a variety of shapes. They can be large, with multiple mounts connected to a frame. Some are also made with hydraulic fluid on the inside to provide more damping and flexibility to help avoid a broken motor mount. The shape, size and materials of an engine mount depends on how much load is applied to the mount and how much energy the mount needs to absorb or dampen from transmitting to the support frame.

The Function of an Engine Mount

two-piece mounts_EM-1The function of an engine mount depends on the vehicle that it is needed for. Here are the four most common types of engine mounts:

  1. Single piece isolator:  These can be used as the front or rear mounts of an engine set.   They tend to be best suited for stationary applications (Gen Sets, In plant power, etc) as there is only an elastomer on the top portion of the mount.  
  2. Hydraulic Engine Mount: mounts with hydraulic fluid absorb more noise and engine vibration. The internal fluid is “pushed” through internal orifices to provide a controlled spring rate. These are most common in vehicles with four cylinders or more, such as large trucks and buses. 
  3. Two-Piece Mounts:  These are great for applications that have high rebound load cases - such as off-road equipment. Think of the need to isolate in both directions.
  4. Base plate for flange mounts. These are for applications where ease of installation is required. These mounts have a base flange that can easily be fixed to a floor or base structure with bolts. No need to recess or insert into a frame. These are commonly used in applications where there is plenty of space to accommodate a mount.

Rubber Engine Mounts

The best material to use for engine mounts is natural rubber. Here are some reasons why you should choose rubber for your engine mount:

  • Versatile in the shapes and configurations to adapt to many different applications.
  • Excellent vibration and noise dampening
  • Long lifespan - correctly selected, a rubber isolator can outlast the engine it is protecting. 
  • Provides a balance between energy absorption and stability for the engine - these are often in conflict.
  • Resistant to ozone, water, oil and other damaging fluids/elements - giving them the ability to perform under tough conditions at low cost.

Natural rubber is the most widely used and common as it is the best material for resiliency or the ability to go back to its original shape. The ability to return to its original shape and not to stay deformed (compression set) is an important characteristic. Is it always the best choice? The best material is determined by what fluids and environmental conditions the mount will be exposed to.

For example, if the mount will be in constant contact with oils or fuel then Neoprene will be a better choice. Constant exposure to sunlight or UV? Then EPDM is the best bet. Need to operate at extreme heat or extreme low temperature? Silicone is the one you need. Need some help choosing the right material? Contact the RPM Industrial Rubber Parts team, we have got your back. 

Because engine mounts are made of rubber, it allows for unique customization. OEMs can design mounts that will fit the application rather than design the application to fit the mount.  Have a mount that has been discontinued? Let our experience match you up with the best part or guidance to move forward. An OEM may also get custom motor mounts made for a few other reasons. With customization, manufacturers can choose the material, shape, colors, size and more. 

Standard and Custom Rubber Engine Mount Services We Provide

Whether you require customization or standard rubber engine mounts, our team at RPM Industrial Rubber Parts has got you covered. When you choose RPM for a custom rubber part, you can expect to work with in-house engineers and team members every step of the way. We will continue to send prototypes until the part is exactly as you want it. 

We also provide standard engine mounts. Here are some of the mounts that we offer:

Our team provides in-depth analysis for what kind of engine mount will suit your applications best. You provide us with the data that we need and we provide you with the perfect mount.

If you are interested in learning more about our standardized and customized rubber part process, give our team a call at (888) 842-5668 or visit our website: 

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If you need rubber, we’ll have it. If we don’t have it, we’ll find it. If we can’t find it, we’ll make it.