Here is a V12 that will fit in a 3/4 scale Mustang. Sounds real good, just like a Merlin should!Hi Jac;
It's the process of growing up. I have the same dreams as many, but without the resources, so no Mustang or Spitfire. I can live with that.
I am happy to say though, that the Merlin Engine dream has not entirely died. Although I'll never own an airworthy Merlin, or likely even get one ground-running, I am gathering together the parts to at least assemble a static display engine. This will keep me busy for years, and my wife understands that I have been saying the word "Merlin" longer than "Nicole." It will be a long, slow moving project with no deadline.
Here's my link to Merlin pictures, and my collection of parts is in one of the albums. The super charger isn't shown, but I do have one. A two-stage beast. https://www.flickr.com/photos/130143587@N02/sets/
But to get back to the Mustang thing, it would have been great to build a replica, but it's very unlikley without tripping on a large, random bag of money. So for those who feel they can give it a try, go for it !