Mysterious Packages Arrived!

"For three months, the whole of the summer term, he worked and worked secretly on the wreck of the old Paragon and Mimsie said that much smoke came out of the chimney and often lights shone all night through the windows, and mysterious packages arrived from engineering factories all over England and disappeared into the workshop through the locked doors."

That's from Part One of Ian Fleming's "Chitty-Chitty-Bang-Bang".  If one substitutes winter for summer, and the US for England, that's a pretty good description of what I've got going on!

Some may question my motives in this project.  I profess to be a British roadster enthusiast, yet I gut my MGB and install Japanese sub-systems.  It seems less difficult to me.  In the wonderful UK, they invented the roadster.  What a miraculous gift!  In some ways it had to be since the Industrial Revolution started there.  Yet, having woken up the world, many other countries caught up.  And, of course, just the passing of 55 years since BB and I were born, has brought massive increases in automotive technology.  I just want BB too have her birthright - the world's greatest tech to accompany her bold, fun spirit! 

The ongoing project to make a sleeper or Q car from my MGB "BB" had to have an engine swap to live out its potential.  There is a rich history of various engine swaps into MGBs.  There is an entire community of MGB V8 conversions.  Other favorites include Miata engines, Rover V8s or the US Buick V6 equivalent.  When I started on this crusade the first time, I had acquired the V6 engine and was in the process of rebuilding it when I stumbled off course.  This time, there were new options available.

My first idea was the mating Honda engine for the rear suspension I installed from the S2000.  This is a remarkable piece of engineering, holding the record for highest hp/l for a production engine for two decades before a Ferrari engine took over (with a slightly different budget!).  It is also an aluminum block 4-cylinder and, therefore, some 30lbs lighter than BB's iron block 1.8l.

Then I got my Hagerty (hagerty) magazine issue which featured the Mazda RX-8 Wankel engine.  My brother had an RX-8 and loved it but I hadn't realized what a marvel that engine was.  It is 232hp and 216Nm of torque vs the Honda engine at 237hp and 220Nm of torque.  In spite of a reputation for "no low end torque" the Mazda and Honda torque curves lay almost on top of each other.  But the real benefit is in size and weight.  The Mazda powertrain is 70lbs lighter than the stock MG but also smaller on height and length by 3" each.  This allows a lower Center of Gravity for the engine of around 3" (based on where I got it to) and Polar Moment of Inertia of the car by around 8%.  That means 8% tractive effort not needed to rotate the car which can be used for acceleration or braking.  I was sold.  And so, on a snowy afternoon, the powertrain arrived.

There are several companies selling engine/transmission combo's on eBay.  My first try couldn't get shipping from Canada due to Covid but the second one from Maryland arrived in a week.  And so began the fitting of the engine.  I knew there would have to be sheet metal movement from the only one other person I could find on the internet who has done a similar swap using the 4 port version of the engine with a 5-speed transmission.  https://www.mgexp.com/forum/mg-engine-swaps-forum.40/build-thread-67b-rx8.2975378/  He did a great job and has already given me some good advice.  

First, the stock engine mounts had to be removed to allow the rotary block to enter.  Inspired by Queen, I texted some friends that she is shorter in length and height, but she's a Fat Bottomed Girl!  Due to the square geometry of the rotary engine.  My air powered body saw was no match for these engine mounts so I did a John Henry!

I pushed the shifter back several inches in an effort to get the engine's center of mass near to BB's!  This felt even more natural compared to the stock location.  It may get more difficult not to bump my McDonald's coffee on the way to the autocross but I should go around corners faster!

The sheet metal of the tunnel is, of course tailored to the production transmission.  The Mazda (or actually Aisin) transmission has different lumps.  So, for example, the inward bump shown below has to bump out a bit.  I have a 3lb hammer, not quite like Thor's, but pretty healthy, that should make that happen!

Below is a view down into the passenger footwell from the engine compartment.  There is actually not much change in legroom as the original firewall had a cone protruding for right had drive models.  I simply moved that over a bit.

My son, Eric had a good idea as we were moving the new engine in place.  He suggested lowering the front suspension cross-member, which needs only 4 bolts, so the right angle could be accomplished.  I was a bit embarrassed, to be honest, since I am the mechanical guy by trade and he is is in software, but I take a good idea from wherever I can and it worked excellently!  Also, I was finally able to change out the worn out rubber pads between the frame and cross-member.
You can see that the engine sits well behind the cross member and seems very happy.  I'm excited to try out the cornering advantages of reduced moment of inertia but I have to go open some mysterious packages from US engineering firms!

Happy motoring and keep having #funwithcars !