The old TVR's used Ford/Buick/Rover engines. These were unreliable and the newer TVR's use in house engines. This is probably due to the fact that they can now afford to make and develop their own.
The Chimaera and Griffith do not use in house engines because they are the old designs (along with Cerbera) that made TVR so popular now. I think they are no longer in production apart from the Cerbera.
You probably havent heard of TVR before because until more recently they were quite rare. Probably like Bristol, Noble, Lister and Caterham - which you may also not have heard of but make fantastic cars.
I only knew about them because my Dad used to really like them. Recently they have become very popular and are making much more cars because they can spend much more on development. So they do not have a long history like Aston Martin or someone.
This is why they are not in Le Mans, im not sure but i think they may have been thinking about entering the Speed 12 into the race. Speed 12 regularly beats cars in higher classes (including vipers etc.) of the Supercar race championships (cant remember its proper name)
TVR stands for 'Trevor' btw - the man that formed the company
