Mercury 305 rebuild | part 4

[@LordDrakenZ]

Love your videos, you're a legend.

[@bennigoodfella2327]

Looking forward to the rest 👍🏼

[@TheDrakenZ]

Well done bro! great video!

[@fishawk90]

Those pistons were in their tight. It should of rotate freely.

[@HGJVerschuur]

why do the gaps of the rings need to be in a certain place? I don't understand why that is of any importance

[@DarkBloodMechanical]

Hi. And that is a really good question that is often overlooked. I will try to simplify the answer. First off, your piston/ring manufacturer will typically provide gap positions in an instruction manual, so its safest to follow that. Now, the 1st and 2nd ring are exposed to the highest combustion pressures, so the gaps are opposite to one another in order to prevent excess pressure from bleeding past the pistons and into your crank case. This is how you get "blow-by". The following 3 rings are for oiling and they follow a similar positioning offset to Retain oil within the rings to lubricate the piston adequately. The final point is why do we have the rings positioned in the same orientation towards the front of the engine, instead of symmetrical. This has to do with engine rotation, As the crank rotates, it throws oil in a clockwise into the cylinder walls. This causes more oil to coat 1 side of the walls. The oiling ring gap positions allow that oil to collect within the piston, and distribute the oil around the piston more evenly. This last point is difficult to visualize. I may explain this in more depth in a future video. I hope this helps.

[@HGJVerschuur]

This surely helps a lot! Thanks for the information. Your knowledge about engines is incredible. Keep up the good work! Gonna use all this information for the rebuild I’m going to do on my 1976 mercruiser 165 hp 6 inline engine. Cheers

[@DarkBloodMechanical]

@@HGJVerschuur I appreciate it! lots of reading, and experience. Don't hesitate to ask questions. In a future project I will be going in deeper depth on a performance engine build ( my personal engine ) and some of these more complex questions will be answered. Thanks for watching, and good luck on the Rebuild.