Looks like some variant of the L24 (240Z, etc).

 

I don't think it's an L-series engine, but likely an RB-series. If you look at the right bank of the engine, it has a 3-bolt, coolant outlet and it appears to have a crank sprocket for a timing belt. Also, the freeze plugs and bolt holes also are consistent with the RB block. Here's some pics of a Nissan RB26 engine:

 

Thanks for the replys, It's sitting at someones house and thought it might have some value.