Twin BMW M73b54 Engines in W24 Hot Rod Madness!

Story by: Dale Pelvit and Gary Kollofski

Edited by: Mike Oswald


All of the stock accessories and drive belts were removed and replaced by a custom system. The alternator mounts between the engines
is driven by a serpentine belt off of the crankshaft. A second serpentine belt runs the water pumps off both crankshafts. The stock tensioners
were converted to manual adjustment and re-utilized. This car is a more race oriented build and there is no air conditioning or power steering.

These BMW V12 M73B54 engines have a well deserved reputation for smooth running (due a great extent to the fact that they
are essentially a pair of smooth running BMW inline 6 cylinder engines connected at the crankshaft with the firing orders
staggered to produce a combustion event every 60 degrees of crankshaft rotation. We are using a similar plan for our compound
engine configuration. Rather than fire the two former number one cylinders at the same time on our W24, we will set the crankshafts
of the two engines 30 degrees apart (mechanically). When the gearbox is installed it will result in a true 24 cylinder firing order
with a power pulse every 30 degrees of rotation! We expect such smooth operation that the engine / transmission combination is solid
mounted to the frame.

The car is still under construction, but it is to the point where some disassembly has begun in preparation for bodywork and paint.
We will soon pull the engine from the chassis, build the oil pans and complete all of the cosmetic work necessary on a show car engine.
Once all of this is complete, the mighty W24 will be run on the dyno to optimize the tune up and establish performance figures. The engines
are left stock internally and based on the factory ratings, we expect over 600 horsepower and 700 foot pounds of torque. The gearbox will
consume some power but not a lot. The W24's power should compare well with the big BPM engine in the '55 Chevy. It made 620 horsepower at
4600 rpm and 720 foot pounds of torque. We ran it to 5000 rpm on the dyno and it will be very interesting to compare the power curves of these
two very different power plants. The BPM is a huge displacement, low compression, push-rod based engine of marine origin. The W24 has less
displacement, twice the cylinder count, the more modern SOHC valve train, and a very different original application. This W24 build is an
amalgamation German engineering and “good old anything goes” American Hot Rodding.

We are eagerly anticipating the W24 dyno session and once that's done – getting into the car. The project has received exposure on the
internet and there is considerable interest in our unusual application of BMW V12 power.

Stay tuned for further developments!

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