manifold/riser gaskets

[rickasbury]

First, I tried to find my original post on selecting the right gaskets for my 350 MPI closed cooling motor...don't seem to be able to find the post? So, had pulled my motor to fix a transom leak, replaced the risers in the process. On the manifold, I have the full flow gasket and in between the top if the riser and exhaust manifold, the full flow. I did not have any coolant issues prior to pulling the motor. I now have coolant coming out the exhaust with the water....what did I screw up? How can I find the original post which had pictures of what I had apart??

 

[alldodge]

replaced the risers in the process

have the full flow gasket and in between the top if the riser and exhaust manifold

You need a solid gasket without any holes

 

[rickasbury]

a little clarification....not coming out of the exhaust but the closed cooling water exit at the transom asy...

 

[GA_Boater]

This thread? https://forums.iboats.com/forum/eng...ard-engines-outdrives/10662650-exhaust-elbows

 

[alldodge]

a little clarification....not coming out of the exhaust but the closed cooling water exit at the transom asy...

Need more clarification

If your talking about the relief ports, this is also part of the exhaust

 

[achris]

a little clarification....not coming out of the exhaust but the closed cooling water exit at the transom asy...

On closed cooling, there are no water exits...

Ok, a few questions...

'Risers'. You have risers with the manifolds and elbows? (See diagram below)
Do you have wet-joint or dry-joint manifolds and elbows?

On closed cooling, the engine coolant only circulates around the block, heads and exhaust manifolds. Seawater still cools the elbows and the heat exchanger. It's still taken up by a raw water pump, and exits through the exhaust pipe (bullhorns) and out through the drive....

Chris.........

Elbow/riser

 

[rickasbury]

OK, I have the dry joint. So on the manifold itself, I have pictured when I took it apart, a full flow gasket. Then the 3" riser. My riser kit did not come with a one piece gasket for in between the top of the riser and the exhaust manifold but little single solid pieces to block that off. So, if I understand the flow...the coolant will come up through the manifold, into the riser and then plumb over to the heat exchanger right? And the raw water that cooled the the heat exchanger would go to the exhaust manifold and then on out the Y pipe along with the exhaust correct? Maybe I mixed up one of the hoses on to the riser/exhaust so I'm shooting out water and coolant? It's not just a little like a leak in the system..I blew out 60 dollars worth of antifreeze . The flow diagram I'm looking at in a manual, can't tell which is water and which is coolant,...just a bunch of arrows going all over the place! I thought I could tell which lines had water vs. coolant by the coloring of them inside... !

 

[alldodge]

As always, its best to let us know what your working on and "Serial Numbers" are best

 

[rickasbury]

 

[rickasbury]

OK, so bit of an update...went to the mercruiser catalog and find the right set up for my hose routing but still a little confused...if you look at the attached...hose number 13 which I take goes from the exchanger to the elbow as water exhaust looks like it comes off the very end which it does not- and the parts list for the end caps of the exchanger are alike- neither of them has a hose connection.. On the top picture above, it looks like hose 12 which comes out of the left side of the exchanger and out of the side goes to the thermostat housing- in the picture above that hose right now is going over to the riser...on the left side of the exchanger there is only one hose I see, not hose 13 and 12....the only hoses I took off were to the riser and elbow! hose diag..pdf I have a 3" riser which changes this a bit.


So, don't know why it won't upload as a doc.....and it's upside down! Sorry!

 

[alldodge]

The hoses that go to each elbow come from each end of the HE. The parts display do not show the exact placement because it is to difficult. They come off just below and under the end caps

No hose coming from the thermostat housing goes to the exhaust elbow, but will go to/from the manifold.

 

[rickasbury]

Thanks...kind of came to the right conclusion after some thought...guess I need to drain what ever mixture is in the coolant system...have not changed the coolant before, is there a drain on the lower part of the manifold?
thanks as always for the help and guidance!

 

[alldodge]

is there a drain on the lower part of the manifold?

No, just remove the hose

 

[rickasbury]

on both sides I suppose.....and I just got the bilge cleaned out.....

 

[alldodge]

Drain the block first so there should be less in the mans.

 

[Bt Doctur]

Pay close attention to how you install the gaskets with the restrictor hole.

 

[rickasbury]

Where is the drain for the block?

 

[alldodge]

Where is the drain for the block?

One on each side and is probably use a 7/16 wrench to remove the pipe plug. Starboard side is behind and slightly above the starter, close to or on a Tee fitting with the knock sensor. Port side behind motor mount and in center of block

 

[rickasbury]

that sounds real fun to get to......really dumb ass mistake I made!

 

[rickasbury]

OK so looked at the hoses....had both sides reversed. I guess when I looked at the hoses, I thought the orangey looking ones were coolant and the "clean" were water- were not apparently. So I was 100 % pumping the coolant out. I drained the manifolds, I could not break loose the drains for the block...how much fluid is in there? Can I put unmixed coolant in there to sorta make up for the water than is in there? And if I had a raw water system, would you not have to drain the water out up north to winterise? Don't they put anything anywhere with the thought of getting to it?!