Correct locations for water heater installation. Stroker 383, 2007

Hello,

I know there are numerous threads about where to install a water heater but I was hoping to get a confirmation for my particular motor.

I have a Mercruiser 383 6,2l 2007 with fresh water cooling.

The service manual tells me this:

I'm fairly certain where I'm supposed to install the return but what about supply? I see a lot of boats using location B but if I'm reading the manual correctly I'm supposed to use A?


Also could anyone confirm if the thread size is 1/2" for the hose adapters? It's a pain getting NPT threaded hose adapters in Sweden since we use a different threading standard here (BSP) and I will have to order these parts from the states.

Also, the hose connections on the water heater (for the coolant) are not plugged. Do I need to rinse it prior to installing it to the engines cooling system?


Regards, Olle from Sweden

I'm fairly certain where I'm supposed to install the return but what about supply? I see a lot of boats using location B but if I'm reading the manual correctly I'm supposed to use A?

Click to expand...

Ayuh,..... "B",.... It's much hotter water, under circulator pump pressure on the block side of the t-stat,....
The "A" port is after the t-stat, aka the cold side,..., 'n it's on the suck side of the circulatin' water pump,....

'n Yes, the ports are 1/2" tapered pipe thread,...

I can't see any reason not to flush the water heater, though it may not matter, dependin' on how much crud has been cycled through it,....

bondo said:

Ayuh,..... "B",.... It's much hotter water, under circulator pump pressure on the block side of the t-stat,....
The "A" port is after the t-stat, aka the cold side,..., 'n it's on the suck side of the circulatin' water pump,....

'n Yes, the ports are 1/2" tapered pipe thread,...

I can't see any reason not to flush the water heater, though it may not matter, dependin' on how much crud has been cycled through it,....

Click to expand...

Many thanks! Any idea why the service manual suggests the other location?

If anyone has these parts laying around and wants to put them in an envelope to Sweden please PM me. I will of course pay via Paypal.

Hello again,

I managed to pull the plug apart It's still "plugging the hole" but I don't see how I can remove it now without drilling into it and that doesn't sound like a good idea...

Is it possible to put a T on any of the hoses instead or are there more places on the engine block where I could place my hose connector?

Thanks in advance!


Best Regards, Olle

The factory 6.2L is 377 cu in SBC.
The 6.3L is the 383 cu in SBC.

The coolant supply (not water in your case) will be taken from port B, of which is up-stream from the thermostat!
DO NOT use A!
A is after the thermostat!

The coolant return will be plumbed into the Stbd most port of the engine circulating pump, as per your first image.

( your second image does not apply ....... it is showing a raw water cooled engine )


The circulating pump charges the cylinder block/heads with mild positive coolant pressure.
The return port in the circulating pump creates mild negative pressure.

This gives the system a much-needed balance that creates flow to and from a water heater or cabin heater.

No other plumbing configuration will work as well!




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RicardoMarine said:

The factory 6.2L is 377 cu in SBC.
The 6.3L is the 383 cu in SBC.

The coolant supply (not water in your case) will be taken from port B, of which is up-stream from the thermostat!
DO NOT use A!
A is after the thermostat!

The coolant return will be plumbed into the Stbd most port of the engine circulating pump, as per your first image.

( your second image does not apply ....... it is showing a raw water cooled engine )


The circulating pump charges the cylinder block/heads with mild positive coolant pressure.
The return port in the circulating pump creates mild negative pressure.

This gives the system a much-needed balance that creates flow to and from a water heater or cabin heater.

No other plumbing configuration will work as well!




.

Click to expand...

Thanks, any suggestions on how to deal with the damaged plug?

olleman said:

Thanks, any suggestions on how to deal with the damaged plug?

Click to expand...

Let's make sure that I'm understanding you.

The plug in the manifold (circled in red and labeled B) is being stubborn....... correct?
If so, you may need to "step drill" it out.

Drain the system of any coolant.
Start in the exact center and drill in a perpendicular pilot hole.
Progressively move to larger drill bits doing a final bore of 23/32" (drill bit size for 1/2" NPT).

Now carefully chase the threads with a 1/2" NPT tap.
Be sure that you are aligned correctly.

You can use a shop-vac to remove any debris.




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RicardoMarine said:

Let's make sure that I'm understanding you.

The plug in the manifold (circled in red and labeled B) is being stubborn....... correct?
If so, you may need to "step drill" it out.

Drain the system of any coolant.
Start in the exact center and drill in a perpendicular pilot hole.
Progressively move to larger drill bits doing a final bore of 23/32" (drill bit size for 1/2" NPT).

Now carefully chase the threads with a 1/2" NPT tap.
Be sure that you are aligned correctly.

You can use a shop-vac to remove any debris.




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Click to expand...

Thanks for that step by step guide, going to be difficult to find 1/2 NPT tap here in Sweden it's hard enough finding the connections

olleman said:

Thanks for that step by step guide, going to be difficult to find 1/2 NPT tap here in Sweden it's hard enough finding the connections

Click to expand...

OK..... then perhaps find a Metric Tapered Pipe thread "tap" and "drill" size that is just over the size of the US 1/2" TPT, and use it.



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RicardoMarine said:

The factory 6.2L is 377 cu in SBC.
The 6.3L is the 383 cu in SBC.

The coolant supply (not water in your case) will be taken from port B, of which is up-stream from the thermostat!
DO NOT use A!
A is after the thermostat!

The coolant return will be plumbed into the Stbd most port of the engine circulating pump, as per your first image.

( your second image does not apply ....... it is showing a raw water cooled engine )


The circulating pump charges the cylinder block/heads with mild positive coolant pressure.
The return port in the circulating pump creates mild negative pressure.

This gives the system a much-needed balance that creates flow to and from a water heater or cabin heater.

No other plumbing configuration will work as well!




.

Click to expand...

I've just found out that my thermostat is in the heat exchanger and not in the thermostat housing, this seems to only be a distribution housing. My engine has the fresh water cooling mounted a couple of years ago, don't know if it's original or not.

Anyway, would it then be possible to use port A instead? I don't have the skills or tools to drill and my mechanic who mostly do cars didn't believe in the drilling idea. He mentioned welding instead which several persons have told me not to do so my trust in him is not 100%...

Hmm just reread second post and it still seems to be on the wrong side of the pump. To bad

There is a return port on the circulating pump on the engine the one on the left side and there should be another pressure port on the intake manifold all your doing is creating a flow of coolant through the water heater coil. You are aware the engine can potentially heat the tank up to engine temp be sure and put a mixer valve in for domestic water.

http://www.marineengine.com/boat-forum/attachment.php?attachmentid=14824&d=1487168453
Use port B there should be another one on the other side as well that is supply
http://www.marineengine.com/boat-forum/attachment.php?attachmentid=14822&d=1487168185
This the return on the circ pump

Olleman, unfortunately there is no other way around this!
And FYI.... I've been doing this type of work since the mid 60s. I've not seen any other configuration work well.

Again....... here's what's necessary:

1...... a coolant supply that is "up-stream" from the thermostat. In your case, port "B" would be ideal!
Why? ..... because the engine's coolant circulating pump is mildly pressurizing the cylinder block and cylinder heads with coolant.
Since the thermostat holds back coolant (releasing it on an "as needed" basis), this creates mild coolant pressure.
This mild pressure in turn creates coolant flow.

2..... a coolant return that is down-stream from the pressurized portion.
Where? ...... the Starboard-most port in the engine circulating pump. (this is in the suction side of the coolant system)
As an alternative, a special Circ Pump suction hose fitting can be added.

Without the pressure differential (between these two areas), you will not see good coolant flow to/from the cabin heater and/or water heater.


It's that simple.

If you deviate from this, you may need what's called an electric "puppy pump", and I would not recomend doing that!


Your call!

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This diagram dont show the check valve for cold water going into the tank or the pressure relief valve. For a closed system the tank will get as hot as the engine you want to protect yourself for scalding hot water.

This shows the check valve and the pressure relief you want to terminate the pressure relief uverboard

Kim, perhaps I'm not understanding your two images.

...... I've not seen a typical Mercruiser SBC Heat Exchanger (such as with Olleman's 6.2L...... ((6.2L is actually a 377 cu in )) set up for supply/return like shown in your recent image.

...... the temporing valve is a nice addition, although it is not necessary unless the owner wants one, or the hot water fixture is open to public use.

...... I'm not understanding the "Engine cooling water header tank" that would be plumbed into the potable water system.

Winters are here and we need to ensure that our water heater works properly. Can the heaters be installed on a small boats also? Is it possible to install a water heater on our own or is it good to call a water heater installation NJ professional? How to choose the best one?

WilliamVue said:

Winters are here and we need to ensure that our water heater works properly. Can the heaters be installed on a small boats also? Is it possible to install a water heater on our own or is it good to call a water heater installation NJ professional? How to choose the best one?

Click to expand...

William, you have posted to (Hi-Jacked) a thread that was last active back in April 2017.
It would be best to start a new thread for your specific topic and question.




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Ayuh,.... It's just Spam Rick,..... A Hvac company in jersey,...