cooling system

ok bought a boat two new 350 chevys with half a fress water system for eng only my ? is what do you think about geting another tank for each eng hooker in series and cool the manfolds?too i have a 350 merc that i put a fresh water system on but its a full system with a bigger tank works great. so im thinking two tanks per eng may be a little expence now but i wont have too change the manfolds in five years.that is pricey for two engs any ideas or thoughts would be great thanks

Ayuh,.... I'd think ya oughta go with Bigger coolers, as I can't think of a reasonable way of runnin' 2 coolers in-line...

I agree with Bill.
When we bring the exhaust manifolds into the Closed Cooling System loop, many things change.

Couple of things first, if you don't mind:
I'm not sure what you are calling a "hooker", so perhaps you could explain.
When you say "tank" are you referring to the Heat Exchanger?
And perhaps explain "two tanks per engine".


When we bring the exhaust into the "closed cooling system" loop, the Heat Exchanger capacity must be increased.
The sea water pump capacity is typically increased also.
I know that BTUs are BTUs, and you'd think that this would be Apples/Apples, but the smaller capacity H/E's for a "Half System" will usually NOT work for a full system..... nor will the smaller sea water pumps.

The thermostat housing changes significantly as well.
Likewise do the coolant return inlets on the H/E.

The risers are also now blocked off from the manifolds completely..... and become fed by the "spent" sea water that leaves the sea water side of the H/E's tube bundle.

What I'm saying is.... the complete system needs to be set up correctly for a Full System, if that's what you want to do.

I'm afraid that you'll chase your tail if you attempt to convert or adapt a half system as to include the exhaust manifolds.

Probably not what you wanted to hear! Sorry!

sorry about that i ment putting two heat exchangers istalled in series.as i have said i have a full system i put on my other boat and thats running off the out drive pump and thats fine i just thought having more water volume would do it/ THANKS for the feed back and thermostat housing would have to be changed and some different hose routing

I'd say check the existing heat exchanger's capacity...it may be able to remove the added heat that a "full" configuration would add. Sure wouldn't hurt to ask...