MED ULTRA LIGHT STEEL FLYWHEEL

MED ULTRA LIGHT STEEL FLYWHEEL

Part No: MED-4100-ULP
Regular price £210.00 £175.00 EXC VAT
Regular price Sale price £210.00 £175.00 EXC VAT
Sale
Availability: In Stock
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Description

One of the most popular lightweight steel flywheels available for the Mini, the MED Ultra Light is CNC machined from EN8 billet and weighs just 3.66kg. This offers a substantial weight saving compared to standard factory flywheels, which can weigh over 7.5kg!

Reducing flywheel mass improves the Mini's acceleration considerably, more so than the weight loss alone.

As a result, installing the MED Ultra Light will make the car accelerate faster, feel more responsive, and is one of the most cost-effective performance upgrades you can make. 

The ring gear teeth are CNC machined into the steel and then heat treated. This will suit any standard starter motor, or alternatively we keep High Torque Starter Motors to match.


 

  • Recommended for fast road and light competition.

  • Weighs 3.66kg - a considerable saving over the stock item.

  • Pre-engaged (129t) or inertia (107t) ring gear option.

  • Supplied with alloy drive strap spacers.

  • Ideal match for the MED Ultra Light steel backplate.

  • Includes timing marks for ignition setup.




Please note - the flywheel will need to be balanced before use. We would highly recommend purchasing a complete kit, which is expertly assembled, centralised and dynamically balanced with all the components required. 

Due to the nature of the heat treatment process, the colour may vary slightly from the images.

Kits are available in various specifications depending on your application, ready to bolt on.  

If you have an EN40B steel crankshaft, the EN24T steel MED X-Lite flywheel is better suited.

Please see the Additional Information tab for more advice.

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Additional Information

Flywheel compatibility

Upgrading to an MED steel flywheel not only saves weight, but also gives a more durable surface on which to grip the clutch plate. The lighter the flywheel, the faster the engine will be able to increase/decrease RPM, making it more free-revving and responsive to throttle input.

Our lightest possible clutch and flywheel setup (X-Lite) is ideal for a competition car, whereas a road car will benefit from more flywheel mass to retain drivability in traffic. 

The MED EN8 Ultra Light is therefore an excellent choice for performance road and trackday cars - lighter than standard yet still usable on the road. It is also the choice for Mighty Mini and Mini Se7en S-Class race cars.

This flywheel will suit all transverse A-Series engines (Mini/Metro) with a pre-Verto clutch setup. It is possible to convert from Verto to pre-Verto by purchasing the MED Heavy Duty Clutch Operating Kit. Please note - this will not suit fuel-injected Rover Minis. See the MED SPi Flywheel or MED MPi Flywheel for these cars. 


Pre-engaged or inertia?

This relates to the ring gear and starter motor installed on your Mini. Inertia is the original style starter motor that uses a separate solenoid unit on the inner wing, whereas pre-engaged has an in-built solenoid. If you have one of our High Torque or Micro starter motors, simply choose the correct flywheel to suit.

For reference, pre-engaged flywheels have 129 teeth on the ring gear, inertia types have 107 teeth.


Alternative options

The later Verto system introduced in the mid-1980s makes a good alternative for a performance road Mini. This design gives an easier clutch pedal, which might be preferable for daily drivers, however the overall assembly does weigh around 2kg more.

The MED X-Lite Flywheel is the best alternative for full competition Minis, featuring larger cut-outs and an integral ring gear for the starter motor. It is also machined from a higher grade of steel, so has less chance of fretting on the taper of a competition EN40B steel crankshaft.

Fitting advice

We would highly recommend purchasing a complete balanced flywheel assembly and fitting it in one piece to retain the balance. You may wish to lap the flywheel gently to the crankshaft taper before fitment, being careful to remove all traces of paste before final installation.

Firstly lock the engine in position with a Mini flywheel locking tool. Torque the MED pre-Verto flywheel bolt to 130lb/ft, to seat flywheel on the crankshaft taper.

Now undo the bolt, apply a drop of standard-grade thread lock to the thread and re-torque to 130lb/ft. This will ensure the flywheel is properly seated on the crankshaft taper.

Frequently Asked Questions

Which classic Minis does this flywheel suit?

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This flywheel will suit all transverse A-Series engines (Mini/Metro) with a pre-Verto clutch setup, excluding the very early 850cc cars with a 'thin tail' crankshaft - quite rare today. For reference, these measure 1.375" at the start of the crankshaft taper, rather than 1.5". This flywheel can also be retrofitted to a later car by changing the clutch mechanism. We can help to make the conversion easier with our clutch arm kit, part number MED-4810-HDK.

How does this compare to a standard Mini flywheel?

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These are machined from certified EN8 steel billets compared to the cast iron originals. As a result, we can reduce the overall weight far more than is safely achievable on a standard flywheel, which are brittle in comparison. The ring gear teeth are also machined into the steel, then specially heat treated, for much improved longevity.

What's the performance advantage of this flywheel?

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Upgrading to an MED steel flywheel saves weight, and gives a more durable surface face on which to grip the clutch plate. The lighter the flywheel, the faster the engine will be able to increase/decrease RPM, making it more free-revving and responsive to throttle input.

Which ring gear style do I need?

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The inertia style suits the original Mini starter motor, as fitted from 1959 to around 1980, when the Metro was introduced and starter motors began to transition to the more modern pre-engaged design. As a quick reference, the inertia starter motor has a separate solenoid unit and the ring gear has 107 teeth. The pre-engaged starter has an in-built solenoid and will engage with a 129-tooth ring gear. If you have purchased one of our high-torque starters, simply match the two together.

Will this flywheel increase the power of my Mini?

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No, changing the flywheel has no effect on the power output of the A-Series engine, however it does increase responsiveness and acceleration by reducing rotational inertia. Reducing weight from the flywheel in particular has a far greater impact on acceleration of the Mini than weight loss elsewhere, so is highly recommended for all performance Minis.

Is this suitable for road use or competition?

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Both - we regularly supply these flywheels for fast road or competition usage.

Is this flywheel balanced?

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We would highly recommend that you have this flywheel balanced alongside the complete clutch assembly, as we do not pre-balance flywheels when supplied as a stand-alone item. That said, by design this flywheel is well balanced, with carefully positioned lightening slots and the integral ring gear, which avoids using a separate shrink-fitted and welded gear.

What are the three spacers for?

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These are drive strap spacers. The MED steel flywheel is considerably thinner in cross section than a standard Mini flywheel, so we include these spacers to reset the position of the steel drive straps that connect to the clutch cover and flywheel back plate. You must use these when building up the flywheel as an assembly.