Porsche 911 RSR 4.0 Liter Twin Plug  MFI Engine
Spotted in Bochum, Germany is a Porsche 911 RSR 4.0 Liter Twin Plug MFI Engine for $53,350 USD.   This engine is based on the FIA international sports law for group 5 and built on an original 3,0l engine case, but increased to 4,0l displacement.  The displacement is exactly 4000 cm³. The torque is 415 Nm and the power output 390 hp at 6900 rpm.  The maximum allowed rpm is 7000. The set up is dedicated for rallye and street use with the target of a broad and constant torque range, even at lowest rpm’s. So already from 3000 rpm, it provides more than 350 Nm with a smooth and flat torque range up to the maximum of 7000 rpm.  It is equipped with Bosch mechanical fuel injection (MFI), authentic Bosch design twin plug ignition and RSR exhaust system from stainless steel.  The engine comes ready to mount, complete with RSR engine mount, flywheel and sheet metal from amber fiberglass.  The engine has been tested, fully tuned and at full power measured on a stationary engine dyno bench.  It is fully documented and ready to race.  This engine was undergoing many detail improvements, based on our long experience of building high end race engines in order to increase the durability.  There is no core needed. The engine is sold outright. But please regard that the price does not include any tax or duty what certainly will apply while importing it to the US.  I have been lusting after this engine since it came up for sale.  I would really like to put this into my 1973 911 while I freshen up my RS engine.  Hopefully members can give their opinions on this motor?  Would it be reliable?  I have never seen a 3.0 engine increased to 4.0 Liter?  Do you believe the claim that it puts up 390 hp at 6900 rpm?  I have been talking to USA builders to see what it would cost to build this here.
What do you think of this engine?
Does anyone else have a comparable engine for sale?
Price $53,350 USD
What do you think?