Water Diverter ?

[W2F a V-King]

Rather than start a new thread, I just have a question or two about diverters.

Have built some Merc V6 fish motors over the years, and in none of them were there any diverters that I can recall.

I have a Pro Max disassembled right now, ( my first real non fish motor ) and it has no diverters...however it was not a virgin block when I got a hold of it.

I have thumbed through my Merc shop manuals..no mention of these guys.

So Please help me understand why these are necessary? Not trying to be a wise guy...I honestly don't understand adding these?

Thank you,

James

[Steve Pope]

Promaxs did not have diverters from factory. the 225x engines had them.Looks like your diverter moved. Because it was in the wrong position it would certainly have disrupted water flow around # 4 cylinder, but by how much?? I assume the engine still runs a poppet valve and thermostats?? If it does run a poppet I suggest you position the diverters correctly or leave them out altogether. By the way, bottom diverters are 1 1/2 inches long, the uppers 1 1/4 inch, both are positioned mid way between the block face and bottom of water jacket. The diverter lengths are listed in the 225 x parts list. Cheers

[tux974]

Pete, I'm not a pro or mechanic and certainly not looking to get into a peepee contest but the picture I posted is exactly the way that motor came from Mercury.
Yes, we cleaned the bores and installed new pistons so it was touched.
Yes, Mercury has sent some out without them but then again they have done things that are hard to explain.
The 225X are the later motors so I guess they found the motor benefited from having them for controlled water flow....
I suggest to put them in and yes if you are running a 2pc plate stats and poppet is a must!.......JMHO

[hunternc]

As a matter of information. The motor did have new thermostats and poppet.

[tlwjkw]

(one motor assembler), here comes another "naked block" gotta put rubber thingys in it!
(different assembler), its got steel, not this one......

good enough for tha hot rods (nic) should benefit tha norm also....

[W2F a V-King]

(one motor assembler), here comes another "naked block" gotta put rubber thingys in it!
(different assembler), its got steel, not this one......

good enough for tha hot rods (nic) should benefit tha norm also....

This is my first performance motor rebuild, and wish to do it right.
I do have the performance mercury shop manual and the "fish" motor manuals. No mention of the diverters. 225-260-280.
Was there a mercury service message or the like that I can read to put the rubber thingies in correctly?

Material used, length? Looks like 3/8 fuel line and do they run the length of the cylinder, base to head?

Thank you,

James

[tux974]

Material used, length? Looks like 3/8 fuel line and do they run the length of the cylinder, base to head?

Thank you,

James

Yes 3/8 or 5/16 fuel hose as long as the wall thickness will work. You do not want it super tight where is next to impossible to place but it has to be tight so it does not move once placed. Use a bit of oil to help place it.
Easiest thing to do is take a thin screw drive put it in till it bottoms out and cut the hose 1/4 shorter. That is what I do and I never let it bottom out when I put it in. It should be shy approx 1/8" of surface on both ends.

[Steve Pope]

The penny just dropped!! The diverters on the port side of your engine were on the wrong side of the block. They should be on the exhaust side. The starboard side were correct.Install the 2 different length diverters as I mentioned above.Way back when F1 boats used the high strung 2.0 litre engines we had a service bulletin that advised to install the 2nd diverter 1 1/4 inch long.( the 2 litre originally had only 1 diverter. When we started using 2.5s we installed both. They came out with none.) If you follow the water flow path coming in from the exhaust chest you will see that the diverers make most of the water flow DOWN around the exhaust side of the cylinder as it is the hottest part. Without diverers the water can take a shorter path to the top of the block. Cheers