That is an early style Jabiru 4 cylinder 2 stroke Reed valve aircraft engine cases. There is no particular make or model they will fit as these engine were designed strictly for experimental aircraft and kit planes. Basically a builder would select the powerplant he or she would like to use and then build or modify the nose forward of the firewall to fit the engine. The motor mounts were usually custom fabricated for the selected engine. Most of these engine had no airworthiness certificate as I mentioned before they were for kit planes or E.A.

Opposed 4 cylinder 2 stroke airplane engine

References:

http://www.redbackaviation.com/four-cycle-four-cylinder-horizontally-opposed-...

Reason:
thank you for the opinion, but I am looking for what make and model this will fit

That is an early style Jabiru 4 cylinder 2 stroke Reed valve aircraft engine cases. There is no particular make or model they will fit as these engine were designed strictly for experimental aircraft and kit planes. Basically a builder would select the powerplant he or she would like to use and then build or modify the nose forward of the firewall to fit the engine. The motor mounts were usually custom fabricated for the selected engine. Most of these engine had no airworthiness certificate as I mentioned before they were for kit planes or E.A.

References:

https://www.kitplanes.com/2019-engine-buyers-guide/