Toyota has already built the GZ V12, but that did not stop somebody from creating a Frankenstein V12 using two Supra engines, who probably had a lot of free time on his hands and much imagination.
So a man got two six-cylinder in-line 1JZ-GTE engines of the Supra MkIII and joined them in a V configuration with an included angle of 120 degrees. A custom crankshaft and a custom oil pan and after he was done he had created a 5 liter V12. Of course, the creation of this engine has taken much work and much trial and error. For example, the exhaust manifolds were originally placed on the outside, where we are used to see them, before they take their place in V. Also, to keep the engine running, a custom ECU was nedded and even more tests.
Anyway, the goal of the retired engineer who created this monster, is to equip it with a turbo and make it yield 800 hp.