Maximum PSI Keyed Crank Hub Kit – S55/N55/N54

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  • Regular price $1,299.00


 ********As of 5/9/19 - S55, N55, and N54 are now out of stock/in production.  S55/N55 ETA June 1 2019, N54 shortly after that.*********

The keyed crank hub kit includes the Keyed hub, Crank bolt, Drill, drill fixture, and drill fixture bolt.  The gasket/hardware kit includes OE/OEM gaskets and hardware needed to perform the install.  It does not include fluids or any additional service tools.

We are proud to release our keyed crank hub kit for the S55, N55, and N54 BMW motors.  This keyed solution eliminates the friction washer design that BMW used to affix the crank hub, timing gear, and oil pump gear to the end of the crankshaft.

The original flawed design allows the timing gear to spin independently from the crank, especially when the motor is modified.  Best case scenario the motor needs to be re-timed with new components.  Worst case, the valves contact the pistons requiring a complete overhaul.   Common symptoms are rough running and camshaft angle deviation faults.  We had this issue several times on our shop F80 M3, one of which required valve replacement.  At that point we had this solution machined, and we installed it in our car and a few other test cars last year.  We went from a failure at each event to setting new records at the track and on the dyno.  We have now achieved a best 1/4 mile time of 9.35@151mph, and we just recently made 899whp/805tq on our Dynojet on E85 fuel.  We have two other cars that have made over 1150whp.

 

INSTALL:

Our keyed hub kit requires a skilled technician with access to BMW timing tools and factory repair documents. These instructions are currently available here: https://www.newtis.info/.  Please read our install instructions from start to finish before attempting the repair. If you have any questions, please email sales@maximumpsi.comWe do not offer any guarantee for this keyed hub kit as it is a race only part, including damage from improper install. These supplementary install instructions are provided to assist a skilled technician in addition to the OEM timing and oil pan removal procedure. The final torque procedure differs from the OEM process and is explained at the end of this document. Some install tools that are required are listed below:

2-post automotive lift
¾ inch breaker bar and socket for crank bolt (S55 breakaway torque for crank bolt is over 440 ft/lbs torque!)
Torque wrench capable of OEM crank bolt torque
Crank locking tool
BMW Timing tools
Crank seal/front seal install tools
Engine support cradle
Small 3/8" drill
Tap Magic or other heavy oil for drilling

You will also need the following OEM parts to complete the job at the minimum:

Valve cover gasket set
Front crank seal
(2) front cover seals
(2) vanos bolts
Oil pan bolts
Oil pan gasket
BMW Coolant
Engine oil

The install process requires you to follow the factory disassembly process until the timing gear, oil pump gear, and crank hub are removed. You will also need to remove the oil pan prior to drilling the snout of the crank. We recommend taking the valve cover off before suspending the engine to drop the front subframe and oil pan.

The vanos components, timing chain and cassette is fully removed, or at least lifted out of the way. The oil pump chain and cassette can remain installed, with the chain tucked out of the way. Remove the crank seal for access to installing the drill fixture and shortened bolt. Use caution to not damage the area where the crank seal sits. The rotation/position of the two holes that you will be drilling is not critical, however it is important that the fixture does not move once you have drilled any of the holes.

**** Please check proper fitment of the drill fixture in the end of the crankshaft. S55 fitment has been very snug. There has been a N54 that had some minimal play which can result in the dowel holes not getting drilled on-center. This can be shimmed using layers of foil wrapped around the drill template as needed. If there are any concerns please contact us prior to drilling ****

**** You need to make sure the holes are deep enough to have the dowel pins fit in the crank snout without bottoming out **** We suggest measuring the exposed length of the dowel pins (should be close to .120"). Insert the drill bit inside the install tool so that it protrudes slightly further than the dowel length, putting some tape or a sharpie mark on the drill bit to provide a suggested stop point. Do this prior to installing the drill fixture on the crankshaft.

Tighten the drill fixture with the supplied short bolt to the crank snout. The drill bit supplied is a carbide straight flute bit. It is very hard, and also fairly brittle. It requires good lubrication, slow to moderate speed, and mild pressure. If you side load it, it will snap. Take your time, use lots of lube, and it should go smoothly. We suggest using tap magic, gear oil, or motor oil. In the case of failure, the bits are readily available at Mcmaster Carr or through us. The good news is they typically just fracture and can be removed with a small pick.

Once both holes are drilled, carefully brake clean/blow out the holes with the drill fixture still installed. This can be done while holding a shop vac in the vicinity of the chips. Try not to blow any chips upwards as you do not want to get debris in the assembled top end of the motor. Make sure you wipe any chips or debris that could accumulate at the inside of the front of the motor on the passenger side.  There is an inner lip that could accumulate debris. Wipe that portion with a rag and check with your finger for debris. If it is good, you are ready to reinstall per factory install process.

Tightening procedure: We recommend cleaning the inside threads of the crank and the crank bolt itself, and applying oil to the threads and bottom of the bolt head prior to assembly. We hold the crank hub with a tool from the front of the motor while tightening the crank bolt instead of holding the crank with a flywheel locking tool. This eliminates the possibility of damaging the dowel pins during the torque procedure, and it stops you from twisting the entire crank during the install process. We still pin the flywheel with the locking tool at the same time. 
S55 and N55 bolt torque - 100Nm initial torque plus 270 degrees.   
N54 Bolt torque - 100Nm initial torque plus 360 degrees.


Now turn it up and make some horsepower!

- Maximum PSI