Right! It's just the old Entex Honda engine. They were made in the 70s and really aren't that great when compared to the Monogram and other visible engines of the day. I had two back then - I think they were around $30 or so.
Here's an eBay link to someone who hopes to get $228 plus for one. Ha! Good luck. Check the completed category. One sold for $99 and they're usually cheaper still. They're not much above Fisher Price for detail or realism. Very chunky and crudely cast parts.
Entex Honda