[2K05GT]

how I see it, is that you have a V8 with a flatplane crank with a redline of 8250 RPM, the flat plane crank has a lot of vibration, a friends Lamborghini went through 4 engines in 2 year span, his wife's Ferrari 458 Italia has the same issue.

One difference I have found is that the GT350 has a single intake where as the Lamborghini/Ferrari engines have a duel intakes. I was told that the duel intake reduces some of the vibration due to the firing order being feft/right/Up/Down. Ford got around this by changing the firing order of the 5.2L Voodoo engine. The reasoning behind using flat crankshafts in performance engines. but is all to do with exhaust scavenging.

With a flat plain crank you can produce 2 exhaust manifolds for a v8 that have equal wave dynamic properties easily. That is each manifold has an exhaust pulse every 90 degrees of crankshaft rotation. This enables much better scavenging of the cylinder next in the firing order on that particular exhaust side. This in not the case with a traditional v8.

Another reason I believe flat plain crankshafts are technically superior is that of a cross plane, you have two cylinders located next to each other (in the case of the chevy 5 and 7) firing one after the other. This is not a good idea from a thermodynamic standpoint and also increases the likelihood of inducing crossfire in number 7 hole banging out the head gaskets with detonation.

There are two types of V8s which differ by crankshaft. The V-angle is always 90°. The two types are called cross-plane (crank pins at a 90° angle) and flat-plane (crank pins at 180°). V8 engines have the advantage of not being in need of split crank pins in order to avoid vibrations between cylinder banks.

With a cross-plane V8, however, the last cylinder is not in the same position as the first, so there is end-to-end vibration again. That can be solved by adding counterweights to the crankshaft which cancel the forced created by the pistons. That is possible only in a V-engine with a V-angle of 90° and without splitted crank pins. These counterweights, fitted to an inline engine, would move to the side when the piston moves up or down and therefore generate additional vibration. But in a 90° V-engine there are pistons on the same crank pin which move exactly into the opposite directions of the counterweights (because of the bank angle) and their forces can be cancelled. Cross-plane V8s are therefore running quite smooth but because of the heavier crankshaft they are not as revvy.

Flat-plane V8 engines do not have those problems. They are also more responsive because of less rotational inertia. That increases maximum rpm and top-end power. In addition the crank case can be smaller which lowers the center of gravity.
But why are the flat-plane engines used in sports cars only if there are so many advantages? That's because of the crankshaft itself, the disadvantage of the flat-plane type. As you can see, the arrangement of crank pins is identical to a four cylinder engine which means there are also vibrations, only stronger, as basically two inline-four engines are running simultaneously. In sports cars those vibrations are reduced by using very lightweight pistons and connecting rods. That is of course expensive and because ride quality isn't too important either, the rough characteristics (compared to a cross-plane) are tolerated. Because of the crankshaft, the sound of such an engine is the one of two four cylinder engines. A (typical american) cross-plane burbling cannot be achieved.

In a cross plane V8 the firing strokes are scattered evenly over both banks at intervals of 90deg of rotation. In a flat plane, they are constrained to firing evenly scattered only in each bank, ie 180deg apart from each other when seen as a single bank, but the two banks are 90 degrees apart, and so the firings of the second bank fall in between each pair of firings in the first bank. Result....the overall engine sees cylinder firings every 90 degrees, just like the cross plane.

The more cylinders in an engine then the fewer degrees of crank rotation between firings and so the smoother the torque delivery to the crank, but the pulses put into the crank by the firings are not the only things that cause vibrations. Just the masses moving back and forth (and side to side) cause most of it. Fours have natural nasty vibration modes, as do in-line twos, and Vee twins have some really unpleasant modes. People would expect 5's to be rough, but they are actually quite well balanced. In-line 6's are great, 60deg V6's are nearly that good, but 90deg V6's are all out of whack, and have uneven firing pulses to boot. IIRC V8's aren't bad (cross plane that is), V10's are not naturally balanced (I might be wrong) and V12s are pretty bloody good. I can't remember about triples and VWAG's VR5 motor, and I might have been wrong about one or two in my list. But you get the idea.

Anyway, all this vibration adding high RPM you are going to experience more that the average failures. Oh and then add a 12:1 compression ratio and you get oil consumption. if you don't check the oil and it runs a bit low... well then boom. I check my 2017 GT350 oil at every fill-up
and buy extra 5w-50 Synthetic since it's hard to find in stores. just what you have to do with a track ready car.