troubleshoot cooling system reference

[migunner]

those who want a better way to trouble shoot the cooling can make a t fitting for outlet of raw water pump and put a pressure vac gauge on it, the pressure should be no more than 9 lbs at 3400, and no more than 7 lbs at 2000 or look for a restriction at oil cooler first, and look for the little rubber fins to be in good shape and not twisted in heat exchanger, glue the little bastard in place before putting end cap in place, I foung a copper 1.25" t and soldered a barbed fitting on it for press gauge with a clear tubing to fit it on the outlet of the sea strainer, had 15 lbs at first and after cleaning out the oil cooler of bits of impellers had the system down to current pressure, tested at the aftercooler also. after getting pressure down still was little warm with end cap of heat exch cool so went in and replaced seperation seals under cap and now sits at 195 f will now try a set of 180d f thermos, I think vovlo was on crack when they built this system, will like to see a steady 180-185 on this engine at full load cruise speed, fit the new global impellor made of polyurethane blue so will see how well it holds up.

[kenJ]

Be careful with the Globe. Have heard of many of them failing, hub seperating (spinning) from the moulded fin assembly. Sherwood pump on 21-30 hp universal engine.

[migunner]

wonder if this had ever been a problem for this application kad43 p-a as the pump turns half engine speed, also at what hours of soak, does long term salt water immersion cause corrosion seperation?? anyone know how well this holds up. this is a commercial application at 400+ hours a year.

[kapnD]

Originally Posted by migunner

those who want a better way to trouble shoot the cooling can make a t fitting for outlet of raw water pump and put a pressure vac gauge on it, the pressure should be no more than 9 lbs at 3400, and no more than 7 lbs at 2000 or look for a restriction at oil cooler first, and look for the little rubber fins to be in good shape and not twisted in heat exchanger, glue the little bastard in place before putting end cap in place, I foung a copper 1.25" t and soldered a barbed fitting on it for press gauge with a clear tubing to fit it on the outlet of the sea strainer, had 15 lbs at first and after cleaning out the oil cooler of bits of impellers had the system down to current pressure, tested at the aftercooler also. after getting pressure down still was little warm with end cap of heat exch cool so went in and replaced seperation seals under cap and now sits at 195 f will now try a set of 180d f thermos, I think vovlo was on crack when they built this system, will like to see a steady 180-185 on this engine at full load cruise speed, fit the new global impellor made of polyurethane blue so will see how well it holds up.

Just a word of caution, you need to refer to your manufacturer's specifications before you start changing things to bring the temp down.
Most modern diesels are designed to run rather warm by old school standards, and will experience premature wear and incomplete/unbalanced fuel burn at less than spec temp.
Not to say that you should ignore your impeller or any other part of the cooling system, maintenance is even more critical at the new, higher temps.
BTW, what little bastard are you gluing in place?

[migunner]

newer diesels that are of the common fuel rail design aside there is no reason this older engine cannot run a little cooler and survice to a now older age, after replace head gasket right at the start since manufacture does not use spray copper coat on new parts, then rebuild after overheat from cooling problem then rebuild from cam breaking after rebuilder dropped it, "NOT ME," now at 2400 hours it is by volvo definition old it needs to just run and charter trips without problems on the water this is where I came into the picture, had to do a little research and redesign to make the thing more reliable, now it runs cooler and does not linger at 205deg at cruise, the little bastards I refered to in last post was the seperation strips in the heat exchanger, put a little gasket cement on them when installing them so they cannot walk when installing the end plate. what a stupidway to direct cooling water flow in the most important part of the exchange process