Having a fondness for the Chevy II four from my boat racing days, I've been trying to find some answers for the questions that have come up about the 181 engine.
A trip to mercruiserparts.com has just brought up more questions than answers.
The 181 is 4" X 3.6" with six inch rods. As we had never been able to bore a 151 to 4" I assumed the 4" bore was from the "iron duke" family. However the Mercruiser 181 does NOT have a crossflow head. Pictures of the valve cover gasket lead me to think it may be based on the Chevy II.
SO the new questions: How did they get it to 4" bore? Did they raise the deck height to get 3.6" stroke and 6" rods? Could the rods be 4/6 cylinder versions of the 4.3ltr Caprice V8s powder metal 5.94" rods[often called 6"]?
