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Harley-Davidson’s Milwaukee-Eight is a solid engine and with the right upgrades you can build a Beast.

Just for fun I asked the crew here at Rollie’s what they would do to upgrade a Milwaukee-Eight.  I got too many suggestions to cover all of them so this article will focus on the “Must Have” items, the “Power” items, some “Hidden Gem” items & a couple of “Safety” Items.

There’s no perfect setup for any bike because everybody is different.  I’m not saying this is the one way to upgrade your M8, you have a  lot of options and you need to do it to suit your height, weight and riding style.

This article is here to show you some options… Options that the crew here at Rollie’s highly recommend.  I hope this helps spark your imagination and motivates you to build your dream setup.

Have a browse through our list below and you can click on the buttons or images for more info on any particular part that catches your interest.  If you have any questions you can always call us on 07-3252-5381 for a chat to make sure you’re looking at the right parts for your bike’s model and year.

Must Have Items For Your Milwaukee-Eight

Performance manifold for M8 Engine

55mm Performance Manifold

Plastic parts are not really cut out for the extra sizzle that comes from a bigger engine doing its thing at full tilt. What you really need is the S&S 55mm High-Flow Cast Aluminum Manifold. This isn’t just some plastic to metal swap; it’s the key to unlocking more Horsepower from your M8. This sturdy game-changer ramps up the airflow big time, marking itself a “Must-Have” for engine reliability and more power.

More Air = More Power

Let your M8 Engine breathe with this 55mm Performance Manifold made by S&S Cycle.

These are a “Must Have” for anyone adding a Big Bore Kit to your M8 Engine, the OEM plastic manifold was not engineered to handle the increased heat and pressure.

Piston Cooling Jet Kit for Milwaukee-Eight Engines SS310-1203

Dual Spray Piston Cooling Jet Kit

Hot engines rob power, and that’s the opposite of what the crew at S&S is all about. That’s why they developed this all-new Piston Cooling Jet Kit for 2017 and up HD® M8 engines.

The Patent-Pending Dual Spray Technology allows the jet to spray evenly on both the piston’s intake and exhaust sides, creating an engine that runs cooler, generates more power, & improves durability.

These are a “Must Have” for anyone removing M8 cylinders, the OEM piston jets are one of the weakest links in the engine.

Vented Dipstick by Feuling Parts

Feuling’s vented dipstick removes unwanted build-up of blow by, which is found in engines with excessive leakdown through the rings/cylinders. This is a common issue with large displacement big bore engines.

Test results show a decrease in engine sump oil levels.

The Feuling dipstick also vents excessive pressure from the oil tank through a breather system consisting of a filter element and umbrella valve.  this helps your engine breathe and allows you to access more power to your wheels.

A quick and simple “Must Have” upgrade for M8 owners.

M8 Tappet Cuffs by S&S Cycle

Let’s play “Spot The Difference” 👀
Just look at the strength of this S&S part in comparison.
Seriously, if you’re boosting the power of your M8 engine why wouldn’t you switch out the stock tappet cuffs for some top quality S&S Tappet Cuffs?
As you increase the horsepower of your M8 you increase the stress on small parts like these. Something as simple this stock tappet cuff can twist under pressure and ruin your day in a very expensive way.

M8 Oil Control Valve by S&S Cycle

The stock assembly includes a check ball retainer that is formed steel. Over time, this retainer can fatigue and break, causing chips to flow through the oil system, back into the tank and can cause significant damage along the way.

The S&S Oil Control Valve is constructed of 6061 Billet Aluminum, and the Check Ball Retainer is machined from High-Strength Steel for long-lasting durability.

Don’t risk the integrity of your performance engine!

If you’re boosting the power of your M8 then include an upgrade to this superior quality S&S part before something goes wrong.

Hydraulic Slave Cylinder by Rekluse

Another easy bolt-on upgrade is the Hydraulic Slave Cylinder made by Rekluse Clutch rEvolution.

This unit can reduce the clutch lever pull by 30% on Milwaukee-Eight models.

You can reduce the lever pull even further if you replace the stock clutch with a Rekluse TorqDrive Clutch.

The end result is smoother gear changes and less fatigue on your clutch hand.  that can be a big bonus on long trips & short shitty city traffic rides.

I see this as a “Must Have” because I can’t see any reason why you wouldn’t want the benefits of a smoother, easier ride.

Power Items For Your Milwaukee-Eight

Big Bore Kits by S&S Cycle

An obvious Power upgrade for the Milwaukee-Eight…

You can take your 107ci up to 124ci or grow your 114ci to 128ci.

This will give you a noticeable increase in Torque and Horsepower.  These kits recently had a price drop due to improved exchange rates so now is a great time to pick up one of these for your ride.

475C Chain Drive Camshaft made by S&S Cycle

The 475C Chain Drive Camshaft is a true 100+HP Bolt in Cam for 2017up Milwaukee-Eight Harley-Davidson models.

It’ll give you a balanced boost in high-end Horsepower and almost instant Torque for that quick take off from the lights. 

We’ve fitted these on a lot of bikes here at Rollie’s.  Click on the button below for more info about the 475C and take a look at the Dyno Charts…

Ps. You can also get this in a bundle… The S&S Cam Chest Kit is a serious Power Upgrade to put a huge smile on your face. 

Hidden Gems For Your Milwaukee-Eight

Forged Roller Rocker Arms by S&S

This is in the “Hidden Gems” section because it’s a part you don’t see and most people don’t think to upgrade these.

If you’re running a standard engine then these may be overkill but if you have modified your engine then these are an important link in your valvetrain (should be in the “Must Have” section).

If you have Cams with .550″ or greater lift then you need these!

There’s a lot of info on the benefits of the S&S Roller Rockers, click the button for more details

Super Cush Drive by Alloy Art

This funny looking green thing is the highest quality dampener available to replace your OEM dampener.

The Super Cush is made from proprietary material that has been developed & tested in the lab and on the street.

These have been around for years and proven to be as tough as they promise.  They will not deteriorate or compress like the OE dampener.

Frame Stabilizer by Alloy Art

The Milwaukee-Eight is a great engine but it does have some annoying wobble issues when you’re pushing it hard.

The awesome team at Alloy Art have come up with a simple and very stylish solution that’s easy to install on your Milwaukee-Eight 2017up Touring Bike.

This is a top quality unit made of CNC machined aluminium and stainless steel to strengthen your frame.  A simple add-on that prevents frame flex, frame wobble and controls motor oscillation.

If you’re experiencing any of these issues then this is the solution you’ve been looking for.

Safety Parts For Your Milwaukee-Eight

Super Bright LED Headlight & Passing Lamps by Hog Lights Aust.

The two biggest dangers when riding are “Your Own Ego” and “Other Vehicles”.

Having a crash because you’re showing off is all on you but having a crash because another vehicle hits you or runs you off the road is far too common. A simple solution to make yourself more noticeable is a decent set of headlights…

Hog Lights Australia make World Class Headlights for most Harley-Davidson models.  This bundle has a 7″ Headlight and 4.5″ Passing Lamps for Milwaukee-Eight Touring models.

These super bright LED lights will make you more visible to other vehicles.  It will also light up more of the road ahead off you so you can spot potential hazards sooner.

Wave Disc Rotors by GalferUSA

This is most relevant for the Touring models…

Your Bike is HEAVY!

If you’re increasing the Power so you can accelerate quicker and open it up on the open road then you also need to upgrade your stopping power.

If you don’t keep a balance between your power to move and your power to stop then you’re riding on a ticking timebomb.

Galfer are heavily involved in motorcycle racing so you know they have done a ton of research and development for their rotors. 

Their products a battle tested in extreme conditions so you know they won’t fail you when you need them the most.

Our suggestion for setting up your Tourer is 

Front Brakes: GAL-DF838W (x2)

Rear Brake: GAL-DF681CWS-C

Front & Rear Brake Pads: GAL-FD369G1370 (x3)

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