Quote from wheel4hummer :

Putting an all-aluminum small block V8 in an Elise would not change the weight distribution dramatically...

And how would you know? have you ever actually been in an elise or something similar? you can have as much power as you want my dads car is near engough on the limit of what you can have power wise to use in an elise for race days anything else will be dragster.
theres only one company that do very small V8's but at a cost of £20,000 and are they reliable? are they as fast as clamied all of that has been asked and up to now no-one has ever put one in an elise.
But i woldnt know why you wold even attempt to put one in when you can have a 450bhp S/C honda engine for half the price and is more reliable. 400bhp is just about the limit of a race elise/exige mostly becuase any more than that there is the problem of getting the power down on the black stuff.

Quote from BenjiMC :

In the boot?

Well if you remember Clarkson when he brought out the Exige or Elise or whatever, the black one with I believe the Apache afterwards, he clearly explained how all that Tupperware was stuffed in the boot.

http://www.veoh.com/videos/e95579G3tzYzDd

There it is, it all starts at the 1:50 mark as Clarkson makes his famous remarks.

420bhp Audi V6 in a Lotus Elise chassis.. Featured in evo magazine alongside some exotic machinery on the autobahn. I don't have my copy to hand but IIRC they were quite complimentary about the handling and overall balance of this Esthi.

You could always just drive a V8 powered Ariel Atom

the owner of those cars will prob die

Quote from pearcy_2k7 :

And how would you know? have you ever actually been in an elise or something similar?

Well, a Miata is about the same weight as an elise, right?

Quote :

Q: What is the weight distribution after the conversion?

A: With a half tank of gas, 53/47.

http://www.monstermiata.ca/v8_miata_cars.html

Quote from ethan520 :

Is it faster to create a light car with a small engine or a heavy car with a huge engine?

I suppose (just guessing coz no-one else has answered your question) that if it were a small custom shop, they may be able to create a light car with small engine faster because of the practical problems of work-space and of dealing with the weight of the engine... bigger frame members means more welding so takes longer - I guess ?... etc.
If it is a production car then the weight vs engine size is probably has little relevance compared with the complexity of the design and the type of materials technology used in the construction...