Raw water cooling routing diagram

About inboard or outboard motors.

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jenko
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Raw water cooling routing diagram

Postby jenko » Fri Mar 14, 2014 4:10 pm

I have few questions about the raw water routing
(1)I have a concern about the exhaust cooling on warm up .Should I add a bypass so the exhaust is cooled all the time and where I added it in Glens diagram is that the right spot?
(2)the engine oil cooler should that be positioned after the water is warmed ?
(3)The trans cooler should that be positioned with the cold water
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bob smith
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Re: Raw water cooling routing diagram

Postby bob smith » Sun Mar 16, 2014 3:15 pm

My Merc big block has the oil and trans cooler positioned between the raw water inlet and the raw water pump.
The exhaust is cooled all the time (via a bypass in the thermostat housing) and the cooling water to the block is regulated by the thermostat.
I suggest you Google fresh water cooling diagram for your particular engine and/or supply more info on your engine/exhaust manifolds and the collective wisdom of the Forum should be able to help.
Bob Smith
Chester, SC
Bob Smith
Chester, SC

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kens
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Re: Raw water cooling routing diagram

Postby kens » Sun Mar 16, 2014 6:32 pm

Im with Bob on this one.
There is many individual applications for marine engine cooling, but, a few things remain constant:
The oil cooler(s) get their water First, then the engine gets its water, then the manifolds, and it all exits overboard via the exhaust elbows (risers)

The engine can have many variations, with raw water pumps, circulating pumps, closed cooling, raw water cooling, etc. If you using the Jaguar circulating pump, I wonder how it will hold up? Do you have a cooling circuit diagram for the Marine version of the Jag?
Oak is over rated, everything about it takes extra time; then it warps, splits or checks !!! :roll:

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jenko
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Re: Raw water cooling routing diagram

Postby jenko » Sun Mar 16, 2014 7:06 pm

photo of starboard side .so I run water from pickup to pump then engine and trans coolers into bottom of exhaust log out top of exhaust log to engine (where circulating pump used to be) out of heads to thermostat (bypass type)bypass hose goes to T in pump inlet and hot outlet to water cooled exhaust elbow and out exhaust.
Ok I guess the question is do I need to send water to the elbow and exhaust on the warm up cycle ,
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Rich Coey
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Re: Raw water cooling routing diagram

Postby Rich Coey » Sun Mar 16, 2014 7:09 pm

Here is a picture with notes on my raw water setup. I like simple and easy to service. Like Bob & Ken said the water comes from the pickup on the bottom of the boat then through any coolers you have. On my setup the pickup hose (A) goes into a cam driven water pump (B) ( Available from Glen-L ).
Out of the pump through hoses (C) and into T's (D) that go into the front of the block and out of the T's up to the top of the thermostat housing (E), it is a special housing ( Available from Glen-L or Rex Marine ). The housing has four connections - 2 on top and 2 on the bottom - with a valve in between. When the thermostat is closed the valve is open which lets the water from the top flow down and out through the lower hoses (F) to the exhaust manifolds then through the risers and out. When the thermostat is open the valve closes and the water flows through the engine and out the lower hoses (F) to the exhaust manifolds. With this setup everything is easy to get to, the impeller can be changed on the water in a matter of minutes.

Note: This setup requires a thermostat with a small hole in it to allow the block to fill up with water ( it comes with the thermostat kit ) without it the engine can overheat.

Rich
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jenko
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Re: Raw water cooling routing diagram

Postby jenko » Sun Mar 16, 2014 9:57 pm

Thanks Rich , your explanation makes it pretty clear the exhaust risers are getting full flow of water all the time .As I have a thermostat housing on each head similar to yours (1 top and 1 bottom port and flow from the head)I will have to ponder about this a bit more as to the routing as I am not sure the thermostat operates the same as yours. Cold all flows out the bottom port and hot all flows out the top port ,so I think I just have to do the same as yours except reverse the top and bottom hoses

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jenko
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Re: Raw water cooling routing diagram

Postby jenko » Mon Mar 31, 2014 1:10 am

After much thinking what i need is two of these http://www.glen-l.com//inboard-hdw/91800-info.htmlbut with only two outlets (one top and one bottom) and I can put one on each bank.Unlike the Chev the Jag has its thermostat outlet on each head on the outside as I have bypass thermostats I can eliminate the possible problem that rich mentioned (air bleed problem cold) so I was hoping that someone might have seen the same thing in use on an inline 4 cyl or 6cyl engine .
Which would be easier to adapt commercially made unit rather than fabricate my own.
My other option would be to buy two Chev ones and block two ports on each , but I would rather have something that looks like it is made for the job.
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jenko
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Re: Raw water cooling routing diagram

Postby jenko » Mon Apr 20, 2015 2:13 pm

Ok guys thought I would post the outcome of the jag cooling system I went with two of the rex marine type (Australian version)one per bank and put the tee pieces on the manifold rather than the front of the block .
so the flow is water pump,oilcooler,vdrive cooler,exhaust logs,(cold)thermo bypass out exhaust,(hot)engine, thermostat out exhaust .
As with Rich Coey's system the thermostats came with a bleed hole .
Bench tested seems to work fine Holds 70deg c, on first test more water came out one bank but was fixed after I removed the swarf stuck under one of the by pass valves ,but the water pump supplied enough water so was not a problem anyway.
posted a video of first test
https://www.youtube.com/watch?v=o9G6cUf ... e=youtu.be
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