For the sake of looking original, I have seen someone hollow out an old Rolls Royce engine and use it to cover a custom-made engine underneath. That sounds pretty excessive to me, but it is a good way to make an original looking engine out of an antique that is not engineered well enough to otherwise bother with. Likewise, going very far out of your way to improve the DeLorean OEM engine is like trying to make a silk purse out of a sow's ear. Just on what level do you want your car to look original anyway? If someone walks around a DeLorean and does not notice a modern non-PRV engine hidden under a closed engine cover, is that situation very far removed from someone making changes inside of an OEM engine? If the change is not readily visible, then is that supposed to make it okay? The only people you would impress are the ones who know what an original engine is supposed to look like. Quite frankly, at non-DeLorean shows, people are disappointed to see the PRV engine in my car. It is not at all what they expect to see. If I bring my car to a major DeLorean event and never open my engine compartment, would anyone really notice that I could have a cold fusion reactor in there? Would it matter? Now with adding turbos to a DeLorean... What's the point of keeping the OEM engine in there if you are going to cover it up with stuff that doesn't belong on it? Do you honestly think you are preserving something original by drilling holes in it and replacing who-knows-what to add the turbo? If you really want to preserve the engine then put it in a crate. Put a decent more modern alloy block engine in your DeLorean and stop worshipping that old PRV. If you really want to impress the purists at shows with your DeLorean then cover your modified engine with a hologram of an unaltered one. Soon we should have the technology to make this look real. Would this be very different from the situation concerning the hollowed out Rolls Royce block? I call this upgrade Stage Five. ROTFLMAF! Enough said?