Alright, before all the naysayers come out, it's clear we're not referring to the inline-4 engines that come in the Lexus IS 200t and ES 250 and so on and so forth. We're talking about the big-boy engines, the V6s and the V8s found in models at the pinnacle of the Lexus model range.
For those who don't know what a V type configuration is, it's fairly simple to imagine. In the case of a V6, you have to imagine two inline-3 cylinder engines connected together at an angle with a common crankshaft, while a V8 has two inline-4 engines connected together at an angle with a common crankshaft. Each of these individual 3 or 4 cylinder blocks are known as banks, and the angle of the "V" is particularly important.
In the case of the V6, the bank separation angle is 60 degrees. This goes up to 90 degrees for the V8, and the rationale for each of these is mostly to do with the cancelling of forces. There's a lot of mathematics involved with this, as well as considerations for space constraints and packaging, but the choice of separation angle is key to ensuring smooth engine operation and balanced power outputs.
But all of this is fairly par for the course. What Lexus has done is implemented a lot of old-school and new-school techniques for engine strengthening in order to make their V6 and V8 engines more reliable - the former in the case of the LS 500 flagship sedan, and the latter in the case of the LC 500 flagship coupe. Both of these engines may be subject to a lot of stress during their lifespan, and as such must be designed to cope with it.
In both V6 and V8 engine configurations, the common crankshaft between the cylinder banks is held in place by a number of crank caps. These caps are bolted into the block from the bottom and have a semicircle cut out to mate with the bearings that go onto the crankshaft. For the Lexus V6 and V8 engines, there are 4 and 5 crank caps respectively, and they are all made of high-tensile heat treated steel.
Now, most manufacturers would use two bolts to hold each crank cap in place, regardless of configuration (except for boxer engines, those are a little different). Lexus decided to go with a whopping four bolts, doubling the number of bolts that come in from the bottom for extra strength and to resist the higher stress these engines are placed under. In some cases they also include a lateral bolt that comes in from the side of the crank case to further secure the crank cap to the block.
It's this type of thinking that some may regard as over-engineering, but others come to appreciate as the reason Lexus vehicles are so reliable. These are techniques derived from engine builders in the past, with a little bit of leeway from the design stage to incorporate them into the road-going engine block design. Both Lexus and Toyota, together with Yamaha, have been developing numerous high-performance, highly-potent engines over the decades - as far back as the 2T-G, to the infamous 4A-GE, to the 3S-GE BEAMS and the JZ family of engines. Each generation has incorporated some form of motorsports-derived engineering, and the payoffs are in both performance and reliability.