OMC Cooling ENGINE using FLust Kit

longstand · May 2, 2009

I have a OMC V6 3.8 Engine

Engine:
------------
OMC
Model# 382STMRCNG

this engine is from my old 1983 Regal Ambassador 247 XL

-------------------
History of the boat.
I purchase the boat 1 year ago. it run fine. but ones i put the boat into the water it overheated both engine

Someone told me it may be the water pump. so i remove the water pump thats on the engine and it was fine. The water pump was rusted and where the water inlet that goest to the Engine

Well I remove the Exhaust manifold and found out that is rusted also, i clean it up and it's all good now.

While i remove the Exhaust manifold The EXHAUST RISER PART #910158 was so rusted i hit it with a hammer it made a hole ( boat RISER On One ENgine )

So i purchase two OMC EXHAUST RISER PART #910158.

Well iam going to put all this part this coming Saturday. and i need some advice of what may cost this Overheating problem.

So far I think its the water pump that is on the Sterndrive is causing this problem.
My Idea is-- if it is the water pump that is on the sterndrive is damage. i will connect a Hose from Flush To a High Power Water pump that will get the water from the sea to the Engine

I look at the diagram it seems like what ever water that goes from the water pump from the sterndrive go to the same area.
---

My Fist Big Boat. Have some question.

Do the SternDrive has to be cooled ? Or only the Engine needs to be Cooled.

Iam not really sure what is sterndrive but is it where the propeller is located. the big bulky Metal Hanging out on the *** of the boat is a sterndrive?

What kinda Lubrication Should I use to Maintain this Boat Beside the Engine and Powerstering. I mean the Gear Oil and the Trim .. LOL iam pulling all this from my SOLOC Boat Manual. It said i should use Gear OIL to maintain it. but did not mension what kinda oil..

What OIL's Should i buy?

What is the Easy way to find out if the water pump located next to the propeller is working?

WizeOne · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

longstand said:
I have a OMC V6 3.8 Engine

Engine:
------------
OMC
Model# 382STMRCNG

this engine is from my old 1983 Regal Ambassador 247 XL

-------------------
History of the boat.
I purchase the boat 1 year ago. it run fine. but ones i put the boat into the water it overheated both engine

Someone told me it may be the water pump. so i remove the water pump thats on the engine and it was fine. The water pump was rusted and where the water inlet that goest to the Engine

Well I remove the Exhaust manifold and found out that is rusted also, i clean it up and it's all good now.

While i remove the Exhaust manifold The EXHAUST RISER PART #910158 was so rusted i hit it with a hammer it made a hole ( boat RISER On One ENgine )

So i purchase two OMC EXHAUST RISER PART #910158.

Well iam going to put all this part this coming Saturday. and i need some advice of what may cost this Overheating problem.

So far I think its the water pump that is on the Sterndrive is causing this problem.
My Idea is-- if it is the water pump that is on the sterndrive is damage. i will connect a Hose from Flush To a High Power Water pump that will get the water from the sea to the Engine. Leaves me with an uneasy feeling but it should certainly work. You better be sure to have the pump turned on before you start the engine or you will cook the shift cable.
I look at the diagram it seems like what ever water that goes from the water pump from the sterndrive go to the same area.
---

My Fist Big Boat. Have some question.

Do the SternDrive has to be cooled ? The sterndrive will get it's cooling by simply being in the water. Or only the Engine needs to be Cooled.

Iam not really sure what is sterndrive but is it where the propeller is located. It is in the bottom of the upper half of the bulky thing hanging out on the *** of the boat. the big bulky Metal Hanging out on the *** of the boat is a sterndrive?

What kinda Lubrication Should I use to Maintain this Boat Beside the Engine and Powerstering. I mean the Gear Oil and the Trim .. LOL iam pulling all this from my SOLOC Boat Manual. It said i should use Gear OIL to maintain it. but did not mension what kinda oil.. The upper an lower gear case uses 75w-90w gear oil. Any variety will work, Marine is best because it has specific anti corrosion additives.
What OIL's Should i buy?

What is the Easy way to find out if the water pump located next to the propeller is working? When you are in the water, briefly disconnect the hose coming from the intermediate housing fitting at the thermostat housing fitting and see if any water is coming out. Should be a solid stream, even at idle.

xxx

longstand · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

What about the rust that has been built-up in the engine where the water pump circulate the water??? How can i remove all that rush. i dont think flushing it with water is good enougth. i think it need some chemical or something. what is good to use to clean or remove all the rush in the engine cooling system that will not hurt any other parts like the gasket or hoses but strong enough to remove the rust

WizeOne · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

There is nothing you can do about the rust build up in the engine block. I also doubt that is where your problem is. Do the test I mentioned on the outdrive water pumps, that is where the problem most likely resides.

longstand · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

I have two engine that needs to be cooled. My boat has a Bate Tank that has a water pump by the engine .. The pump gets its water from the buttom of the boat it also has a filter. The Water pump Pipe really is on the Buttom of the boat.

Iam going to use that water pipe leading to the buttom of the boat that the water pump use for the bate tank behind by boat to cool both engine. i will be connecting it directly to both housing where the thermostat housing.

It has a small pump.

My question is . what pump will work best for this for this project iam doing.
i assume that i need a pump that will feed alot of water to the engine..

How many GPM ( Gallon Per minute is require to cool both engine on idle or high RPM?

I found some pump that i could use
http://www.iboats.com/5_8_GPM_Pumps/dm/*******.121412431--**********.818937955--view_id.272260

I need something that work best but not to expensive
and something that will not burn up.

i need a pump that could run for at less 2 hour before i have to shut it down to cool off.

is there a pump that could run for a long time that will not burn up. i assume if something runs for a long time. it will break.

Dont know much about water pump and how long they should be run.

cooter2506 · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

Seems to me it would be better to get it working the way it should. Rigging it could become costly down the road. If you had rusty manifolds you need to back flush ENTIRE cooling system in both engines to remove all debris and replace both impellers in outdrives. Then check to see how it cools then. Betting it would cool like new.

Howard Sterndrive · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

longstand said:
How many GPM ( Gallon Per minute is require to cool both engine ....high RPM?

340HP of engine requires about 15 to 50GPM raw water flow depending on water temp.
In arctic waters the stat is closed mostly and 15 would probably do it, in tropical water, the stats would be wide open at full oad and the entire 25GPM per impeller pump would be used.

longstand · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

cooter2506 said:
Seems to me it would be better to get it working the way it should. Rigging it could become costly down the road. If you had rusty manifolds you need to back flush ENTIRE cooling system in both engines to remove all debris and replace both impellers in outdrives. Then check to see how it cools then. Betting it would cool like new.

How do you back flush?

Well it seems simple duhh. back flust. but i mean how in and where do i connect the hose too?

Also for my engine. what is recomeded Gear OIL. I know you guys just mention the gear oil. maybe my Engine needs a special one. because i try to purchase an oil at walmart and they have a Gear OIL. but did not mention what GRADE it was. it was just Called (GEAR OIL) and it said its for sterndrive or outboard engine .. something like that..

i have a 3.8 V6 OMC Engine. Its a Inboard Outboard

longstand · May 2, 2009

Re: OMC Cooling ENGINE using FLust Kit

Howard Sterndrive said:
340HP of engine requires about 15 to 50GPM raw water flow depending on water temp.
In arctic waters the stat is closed mostly and 15 would probably do it, in tropical water, the stats would be wide open at full oad and the entire 25GPM per impeller pump would be used.

Would it hurt if i get more GPM??

Meaning if i could FInd a Water Pump that Push 100 to 200 GPM.

Iam thinking if it put that much water pressure into the engine. it will pressure out all the rush and what ever crap is in the water inlet .

i found a water pump that is pushing 250 GPM. its cheap too. can i use that>??
Would it hurt certain part of the cooling or worse but busting some gasket..??

how much pressure can i gasket handle before it start leaking anyway?? i know it very in what type of gasket i use. but general regular gasket. what is the pressure it could handle

By the way. is there a water pump that is 12v that run over 25 GPM. i cant seem to find one..

I found one that is pushing 250 GPM. but its not 12 V

Howard Sterndrive · May 3, 2009

Re: OMC Cooling ENGINE using FLust Kit

longstand said:
Iam thinking if it put that much water pressure into the engine. it will pressure out all the rush and what ever crap is in the water inlet .

a pump doesn't make pressure.
restriction to flow makes pressure.
Once all of the rust and debris is cured with new manifolds, and maybe new engine blocks (would have to see the situation), there will somewhere around 0 to 1 psi pressure once the system is repaired.

the water pump in the outdrive needs to be repaired properly with proper fitting, original design parts. The water pump in the drive cools the upper gear box and the intermediate, as well as the ball gears of your drive system, as well as the engine.
This "re-engineering" stuff never works. The outdrives would fail.

Need to fix it right.

cooter2506 · May 3, 2009

Re: OMC Cooling ENGINE using FLust Kit

BINGO!!!!!!!! Howard is correct. It NEEDS to be fixed properly or it will get expensive to repair when outdrives fail. Search engine back flushing on here and you should be able to see how to do it. Im betting there is alot of debris in those blocks and hoses.

OMC Cooling ENGINE using FLust Kit

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