Redline Speed Worx (RSW)'s BMW M3 F80/F82/F83 S55 Crank Hub Warning!!!!
#1
10-15-2015, 03:34 PM
Redline Speed Worx (RSW)'s BMW M3 F80/F82/F83 S55 Crank Hub Warning!!!!
The release of the most recent iteration of BMW’s iconic M3 was met with some trepidation…. Lots of purists were up in arms over the fact that it was going to benefit from forced induction, while others were happy that at least it was back to BMW’s tried and true inline 6 layout. No matter which side of the fence you rest on the outcome is impressive. 425 hp, 406 ft lbs of torque, and 0-60 times hovering around 4 seconds flat for a rear wheel drive sports car is phenomenal.
The problem is for us enthusiasts, we can never have enough of a good thing..Unfortunately in all of BMW’s infinite wisdom it appears much alike the rods in the E46, and bearing wear issues in the E9X (E90,E92,E93) the current F8X( F80,F82,F83) generation is not without its flaws either. Luckily for owners, the fix is considerably less costly than the previous cars. The issue with the S55 arises from the factory crank hub for the timing chain.
On most modern cars timing belts have been changed over to timing chains, allowing for greater reliability, greater longevity, and more exact tolerances. Having a metal chain riding on teeth allows for the timing between the camshafts and the crankshaft to be kept perfect, unless something goes wrong with the system. This article is not meant to scare M3/M4 owners but merely to let them know that this is an issue that has occurred on a handful of cars already, some stock, some modified, but it appears more likely to happen on a modified car. According to TPG they believe the issue is going to be more common on heavily modified cars where the rate of acceleration is high. What we mean by a higher “rate of acceleration” is simply that the engine is progressing through the rev range significantly faster than a stock car. The redline doesn’t have to be any higher nor does the car have to rev higher for this to occur, simply the force that’s transmitted to the hub via the timing chain overcomes the clamping force of the hub.
What happens is the nut that holds the crank hub on the crankshaft loses tension and the crankshaft and camshaft get out of time. If the hub spins enough, it can cause the piston to smash into the valves. Luckily the guys down at TPG tuning have engineered and produced a worthwhile solution using OEM BMW parts and some ingenuity.
Here is where the Hub sits usually, it has been removed for replacement and upgrade in this photo:
The job isn’t extremely complex but does require a fair amount of the covers and piping above the valve cover to be removed:
What they have done is taken the OEM BMW toothed hub, and cut a relief in the inside of it to provide room for a locating key to hold it in place. The ingenious part of the design is that in case for some reason tension was lost, the key will keep the hub located in the correct position on the crank, saving both the rods and pistons from catastrophic damage.
Key on TPG Hub:
Keyway on timing gear:
The kit retails for 400 dollars which, to us, is a bargain. Considering the reassurance it gives to those who intend on using their M3/M4 as it was designed to be used, driven hard, and potentially modified, a 400 dollar part to keep a 40 thousand dollar engine safe ($ figure calculated off of parts for new long block and labor to swap it) is great value per dollar.
The kit includes:
Keyed OEM Crank Hub
Keyed OEM Crank Timing Gear
New OEM Vanos Bolts (Optional )
New OEM Valve Cover Gasket
New OEM Oil Pump Drive Gear with Friction Disc
New OEM Crank Bolt
If you have any questions regarding your specific vehicle, the kit, or installing it please don’t hesitate to pm, email, or call us directly at 908 223 7477.
The problem is for us enthusiasts, we can never have enough of a good thing..Unfortunately in all of BMW’s infinite wisdom it appears much alike the rods in the E46, and bearing wear issues in the E9X (E90,E92,E93) the current F8X( F80,F82,F83) generation is not without its flaws either. Luckily for owners, the fix is considerably less costly than the previous cars. The issue with the S55 arises from the factory crank hub for the timing chain.
On most modern cars timing belts have been changed over to timing chains, allowing for greater reliability, greater longevity, and more exact tolerances. Having a metal chain riding on teeth allows for the timing between the camshafts and the crankshaft to be kept perfect, unless something goes wrong with the system. This article is not meant to scare M3/M4 owners but merely to let them know that this is an issue that has occurred on a handful of cars already, some stock, some modified, but it appears more likely to happen on a modified car. According to TPG they believe the issue is going to be more common on heavily modified cars where the rate of acceleration is high. What we mean by a higher “rate of acceleration” is simply that the engine is progressing through the rev range significantly faster than a stock car. The redline doesn’t have to be any higher nor does the car have to rev higher for this to occur, simply the force that’s transmitted to the hub via the timing chain overcomes the clamping force of the hub.
What happens is the nut that holds the crank hub on the crankshaft loses tension and the crankshaft and camshaft get out of time. If the hub spins enough, it can cause the piston to smash into the valves. Luckily the guys down at TPG tuning have engineered and produced a worthwhile solution using OEM BMW parts and some ingenuity.
Here is where the Hub sits usually, it has been removed for replacement and upgrade in this photo:
The job isn’t extremely complex but does require a fair amount of the covers and piping above the valve cover to be removed:
What they have done is taken the OEM BMW toothed hub, and cut a relief in the inside of it to provide room for a locating key to hold it in place. The ingenious part of the design is that in case for some reason tension was lost, the key will keep the hub located in the correct position on the crank, saving both the rods and pistons from catastrophic damage.
Key on TPG Hub:
Keyway on timing gear:
The kit retails for 400 dollars which, to us, is a bargain. Considering the reassurance it gives to those who intend on using their M3/M4 as it was designed to be used, driven hard, and potentially modified, a 400 dollar part to keep a 40 thousand dollar engine safe ($ figure calculated off of parts for new long block and labor to swap it) is great value per dollar.
The kit includes:
Keyed OEM Crank Hub
Keyed OEM Crank Timing Gear
New OEM Vanos Bolts (Optional )
New OEM Valve Cover Gasket
New OEM Oil Pump Drive Gear with Friction Disc
New OEM Crank Bolt
If you have any questions regarding your specific vehicle, the kit, or installing it please don’t hesitate to pm, email, or call us directly at 908 223 7477.
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