Help with Yanmar 3gm install

[jmurray109]

So I am in the process of installing a rebuilt Yanmar, that replaced an older Yanmar. I have a question regarding the vent from the exhaust riser. I have attached picture. The mechanic that did the rebuilt has the vent facing down. I was wondering does it need to be down or can I turn it up, so it it is easier to install the vent line.

[jimbunyard]

Sure, as long as its not too loose (it leaks) or so tight you break the fitting or the elbow (oops)...

[tkeithlu]

It's a siphon break. Air goes down just as well as up, and mounting upward is more usual because it's at the top of the siphon loop. I've never seen one mounted downward.

Pretty work you are doing. I wish my engine looked like that.

[Frankly]

On my 3GM the vent/ siphon break is up. One other little trick is to mount it where it won't drip on the engine when it leaks (it will eventually ). On Cbreeze IP actually located it in the laz next to the aft end of the engine. Feed and return hoses are about 3 ft each. Just keep it above the elbow.


Frankly

[jimbunyard]

Originally Posted by tkeithlu

It's a siphon break. Air goes down just as well as up, and mounting upward is more usual because it's at the top of the siphon loop. I've never seen one mounted downward.

Pretty work you are doing. I wish my engine looked like that.

Not sure, but I think he means can he turn the fitting screwed into the elbow up, like this.

[AA3JY]

Something bothersome about the picture.. the exhaust elbow should be reversed so the raw water is on the down side not the up side of the elbow to prevent water from entering the cylinders...

[jimbunyard]

It only goes one way.

The inlet placing is correct; the water comes in on the hot side (nearest the engine), goes through the elbow, cooling it, and exits into the exhaust stream below the bend in the elbow, further cooling it, and then finally the water-entrained exhaust exits the elbow completely.

[jmurray109]

Originally Posted by jimbunyard

Not sure, but I think he means can he turn the fitting screwed into the elbow up, like this.

Thanks, for the photoshop. This is exactly what I meant.

[gonesail]

i seriously doubt it matters which way the elbow fitting is turned.