Bill,
It looks like a variant of their XIO-340 engine. See
http://www.eci.aero/exp/IOX340stroker.aspx
Lycoming also made a 340 variant of their 4 cylinder engine. 340 Lycoming and ECI engines have the same bore as the more common 320 and 360 cubic inch models. The 360 cu models have 1/2" more stroke than the 320 cu models. The 340 cu engines have 1/4" more stroke than the 320 engines. This engine line was developed by ECI for older model Lancairs. Lancairs are very tightly cowled. The reduction in stroke allows the 340 engine to be 1/2" narrower than a 360 engine. The Lancair guys can often fit a 340 engine into certain models, which won't take a 360 (with stock cowl).
I suspect that the 80 hp continuous rating is done for insurance and airframe design limitations. Piper did the same thing with Lycoming 320 cu engines in the 1960s. Remember that the original Piper Cubs had 65 to 85 hp engines in them.
Charlie Kuss