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The K24 BMW E30 Swap Package is Here!

David Calzada

Our long-awaited Honda K series BMW E30 swap package is designed for competitors who demand the BEST with zero compromises: the best design, quality, serviceability, and longevity that’s all backed by rigorous testing on race tracks all over the country. And most exciting of all, it’s the first of many new products that will be launched under the new KPower brand.

We have built our reputation on developing the highest quality K swap components. We have transformed the industry with our K24 Miata engine conversions, and now we’re about to do the same for the BMW E30. While some of these E30 components were developed over the last couple of years, we chose to wait and make everything available once a complete package had been designed, tested, and manufactured.

Why is the K series engine platform so desirable for the E30 chassis? It’s simple - we followed in the footsteps of the BMW M division by pairing the lightweight and nimble E30 chassis with a high revving four cylinder, like the original E30 M3, which dominated motorsports in its day. Sure, you can shoehorn a larger inline six into the E30, but sticking with a four cylinder stays true to the balance and spirit of the car. Our baseline test vehicle made 230whp and 190wtq with a good tune.

The K does everything that the original E30 M3’s S14 engine does except better. The power potential, reliability, cost, and attainability of the K series makes it the best four cylinder engine ever manufactured. The K series engines are in front-running race cars across the globe and once you install one in your E30, you’ll see why.

Most components in this swap package are machined or fabricated in-house in our facility in Wauconda, IL to the highest of standards. We couldn’t be more proud of the end result of this swap, so if you’d like to learn more check out this detailed overview of all available components:

 

Adapter Plate and Flywheel

At the base of our E30 swap package is our proven K series to BMW adapter plate, flywheel, and release bearing. We’ve been manufacturing K series adapter plates since 2014, and in-house on our Haas CNC mills since 2017. During this time, we’ve perfected our designs and process. Since there’s no such thing as a factory RWD K series transmission, retaining the BMW transmission increases simplicity, reduces cost, and allows us to take advantage of the stout BMW transmissions that bolt right into the E30 chassis.



For this package, we offer a K series to E30 Getrag 260 adapter plate, as well as a K to ZF 5-speed (E36/E46) for those looking for shorter gear ratios. 

Our 0.500” bare steel plates arrive in our shop with a precision ground finish to insure flatness within +/- .003”. The plates are fixtured in our machines to maintain perfect flatness during the machining process. All edges are chamfered, and threads are all tapped in the machines. Before being zinc plated, each plate is manually inspected and test-fitted. 

All adapter plates are not made equal. They are often built from thin aluminum, which flexes during installation, and also results in weak threads that are prone to stripping. A thinner plate is always desirable when trying to keep flywheel thickness to a minimum, so despite the extra costs and machine time involved, we use steel to give us the best of both worlds - the thinnest possible plate, and also the most rigid, with the strongest threads that can handle a lifetime of engine and transmission service. 

Our plates include custom zinc-plated bolts with fine metric threads, and are supplied with new OEM BMW dowel pins. Our K to ZF adapter even includes a custom shaped K series dowel to guarantee perfect transmission alignment every time. 

Our flywheel and release bearing combination is also built to exacting standards. Made of 6061 aluminum and weighing in at just 12.5 lbs, it’s designed to be paired with the supplied Tilton extended bearing carrier, which allows the flywheel to be an entire inch thinner than if an OEM bearing were to be used! 



A 15mm ID or 12mm ID pilot bearing is pre-installed depending on transmission choice, and is held safely in place with a circlip. Our flywheel also needs to be paired with an 240mm E46 5-speed clutch kit. Why E46? The pressure plate geometry has more holding capacity, and the flywheel can also accept E46 M3 and E39 M5 pressure plates from ACT, Sachs, and other manufacturers. 

 

Engine Mounts

When we set out to build the perfect K swapped E30 engine mounts, we knew they had to be designed from the ground up to be specific for this application. Although we carry other machined engine mounts that could be adapted to work in this package, we felt strongly that our E30 mounts needed to use the OEM BMW mounting points, and the mount bushings needed to remain in the factory location on the subframe. The end result is a set of mounts that are almost too pretty to put on a car.

Due to the long length of the mount arms, 3/16” steel was the obvious material choice. Each steel plate used in our mounts is CAD designed, laser cut, and precision bent, and then welded in-house by our fabricator. They are powder coated locally and paired with OEM style 10.9 grade flange bolts.

Our mount arms rest on a set of the finest polyurethane BMW engine mounts from AKG Motorsport. These mount pads (Part #MM5030) have a durometer rating of 70A, which is the same hardness as the sought-after OEM BMW Group-N mounts (previously sold for $800 a set!). Stock BMW rubber mounts are 55A, so these mounts are perfect for customers looking for reduced engine movement in the chassis without compromising comfort. 


AKG’s U.S. Military Spec compound is hard, and yet somewhat pliable, with elasticity and memory. The exclusive compound allows AKG to manufacture a mount with high performance characteristics that are free from the deformation that other mounts are prone to. Read here why AKG mounts are the best BMW mounts available



Oil Pan and Pickup

One of the nicest parts of our K series E30 package is that it is truly bolt-in. Zero chassis modification is required. And once again, we took the lead from BMW M and mimicked the M3 oil pan design by building a front sump oil pan that allows the factory E30 subframe and sway bar position to remain unmodified. 


Unlike other one-off Honda E30 engine swaps done in the past, we designed an oiling system that allows the engine to be located in the most rearward position in the engine bay for the best weight distribution possible. While this required more ingenuity and work on our end, compromise was not an option.


Our oil pan, pump adapter, and pickup tube is designed with the road racer in mind. We’ve tested our oiling system at race tracks across the Midwest and have seen consistent oil pressure in every scenario. 


Our pan holds seven quarts, and features baffles and two trap doors for proper oil control. The key component in this oiling system is a slightly modified version of our original K20 oil pump adapter. This piece is installed on a K20 oil pump (required for this swap) and allows the supplied pickup tube to replace the factory Honda pickup that would otherwise point right into the steering rack.


Best of all, the oil pan sits ABOVE the bottom of the subframe! No more smashed M20 or M42 oil pans thanks to this design. Our oil pan is also designed to clear the stock K24 A/C compressor without modification.


Lastly, our pan also has a number of ribs pressed into the larger sheet metal sections of the pan. We’ve learned through experience that these ribs are critical in eliminating harmonics that get amplified across large flat sections. Pans designed without ribs will fatigue over time and eventually crack near the welds. 


Intake Manifold

Our immensely popular RWD intake manifold needs no introduction. While we developed it primarily for our KMiata swaps, it has since become the industry standard for all RWD K series swaps in any chassis. 



The quality, fit and finish, and ingenuity behind the layout and design make it the only manifold designed from the ground up for a RWD swap. It fits like it’s a factory part, and has the runner length, diameter, and plenum volume to make great power on stock engines, 300+whp built engines, and huge power turbo cars. 

 

Our manifold is the ONLY manifold on the market that clears the E30 brake booster and master cylinder, and also allows you to run the OEM Honda idler pulley and tensioner. 


You can read more more about what makes our manifold special here


It’s available with an RBB style flange (K24A2) and also a PRB flange (K20A2/K20Z1). Our E30 swap package also includes brand new hardware and all necessary ⅛” NPT vacuum port fittings. 


Our manifold does interfere with the factory E30 brake/clutch master cylinder reservoir, so this package also includes a reservoir relocation kit.



This combination of a BMW reservoir, fittings, and hose pairs with a bracket from N15 Design for a simple and clean installation.


Throttle Body

Our manifold is specifically designed to mate up to a 74mm B series/S2000 style throttle body. For the E30 chassis, we’ve taken our favorite cast throttle body and outfitted it with our own billet two-piece throttle cable wheel. 

The E30 pedal ratio is much longer than a Honda or Miata, which initially resulted in a very heavy throttle pedal. Our elegant solution replaces the small wheel with a piece that matches the pedal ratio of the E30 exactly. 



Best of all, it pairs up with an OEM E30 318i throttle cable (M42 engine), part 35411158724. The throttle wheel can be unbolted from the base and rotated to any position for perfect throttle cable placement. This level of detail can be found throughout our entire E30 package.



Plug and Play Wiring Harness

Our K series E30 wiring conversion harness is one of the items we’re most excited about. Most notably, it’s 100% plug and play. Just connect it to a 2002-2004 RSX engine harness and ECU (with Hondata Kpro4 installed) and then connect it to the C101 chassis firewall connector under the hood of your E30 and your car will fire right up.



Our conversion harness is divided into two sections. The main harness remains under your dash above the glove box, and the ECU can be mounted in the stock E30 location with some slight modifications. This section of the harness includes the Honda ECU and engine harness connectors, an OBDII port, a connector for the OEM Honda wideband O2 sensor, and three built-in relays. This is all designed to be mounted entirely inside the vehicle.

Our motorsports grade sub-harness connects directly to the under-dash harness through an 8 pin connector, and it’s made of the highest grade materials for a lifetime of use under the hood of any race car. 



We use military grade teflon coated wire, Raychem DR-25 heat shrink covering, a brand new OEM BMW C101 firewall connector, new OEM connector boot, and new OEM pins. It also features a single waterproof inline fuse holder and eyelet to connect to constant 12V power at the firewall power distribution block. Lastly, we integrated an OEM BMW water temperature sensor so the factory BMW sensor can be installed in our upper coolant neck and provide signal to the factory BMW gauges.

With this harness installed, all of the E30 gauges and indicator lights function just like they did from the factory. 

Note that early model cars will want to swap to a late model cluster with the tachometer coding plug located in the front. The older tachs have a hard stop at 7000rpm. Also, the 4 cylinder coding plug must be used for a proper tach reading. BMW part 62111394321. 


Upper Coolant Neck

Our upper coolant neck is needed to route the upper radiator hose inlet away from the firewall and towards the radiator. 

We machine the base out of 6061 aluminum and then weld on a 1.25” inlet pipe to position everything neatly in the engine bay. The coolant neck features a ½” NPT port for the heater hose, and also a plug for those deleting heat. 



We also machine our own coolant temperature sensor bungs to weld onto the inlet so the factory E30 sensor can be retained, as mentioned above. 


Extras

We believe in offering comprehensive engine swap solutions to our customers, not just a couple individual components that leave much of the guesswork up to the builder. 

Because of this, we supply new hardware, including all new oil pan bolts and intake manifold bolts and fittings. You’ll also find our flywheel dust shield included in this package. 


Additional Upgrades

The most notable add-on to this package is an exhaust header. We have designed our own 4-2-1 header and thoroughly tested it, and have already put the first batch into production. They will be available for pre-order in September 2020 and will ship later this fall. 



Thanks to the packaging in the E30 engine bay, we were able to design our header with optimal primary and secondary lengths that gave us the best power and torque curves we’ve ever been able to achieve in any RWD K series platform.

Best of all, it retains factory ground clearance under the car and ultimately terminates with a 3” single exhaust flange. 

 


Another enhancement that will be available within the next 30-60 days is our power steering kit. Our test car has had power steering since day one, and we expect many customers will want this feature. It’s designed to combine the factory K24 power steering pump with the factory E30 steering rack by relocating the power steering pump below the alternator in the A/C compressor location.

By sticking with the OEM hydraulic pump, our system is simple, reliable, inexpensive, and easy to add to any swap. More details and pictures will be available very soon. 

If you’d like to run A/C in your K powered E30, the stock A/C compressor fits in the factory location thanks to the geometry of our oil pan. Customers wanting A/C and power steering will need to go with a hydroelectric power steering pump setup, and we’ll be releasing our own hydroelectric power steering kit as this swap gains popularity.

We also offer an E30-specific valve cover. Not only is it powder coated in a durable wrinkle finish, but the rear breather port has been removed and welded shut since it points directly into the firewall. In its place is a -10 AN bung on the exhaust side of the cover that can easily be routed to a catch can.

Ready to get started? Click here to check out our complete swap package, as well as individual components.

Also, be sure to subscribe to our email newsletter for additional E30 parts coming soon!