Volvo Penta 2003 Cooling

[Seashoreman]

Re: Volvo Penta 2003 Cooling Result

I am considering installing an alternative / additional through hull intake T’d into the saildrive seavalve/hose.
I have done this. But why bother with a T junction? I suggest bypassing the saildrive altogether.

 

[scottie]

Re: Volvo Penta 2003 Cooling Result

Slight thread drift.
This Summer our boat spent much longer in the water than in previous years. We also spent a lot of time static, at anchor or in marinas.
Over the Summer I became convinced that the cooling water flow had diminished from what I remembered as normal. One indication of this was a change in the exhaust note. I also thought the engine was running hotter than normal (by touch on the cylinder head) , although no alarms.
In July I had the heat exchanger checked and rodded – it was fairly clean. At the same time I checked the jabsco pump and the impeller was perfect, but I took the opportunity to change it anyway.
We did very little motoring after July, but the perceived problem persisted.
We hauled out on 5^th. October, and I found what I think was the problem. There were several barnacles growing in the 6 saildrive intake apertures, which clearly would have restricted the water intake flow.
I am considering installing an alternative / additional through hull intake T’d into the saildrive seavalve/hose.

Any thoughts?

Thank you,

Michael.

Main water inlet is actually the hole under the nose of the drive and should be cleared on an annual basis

 

[Tim 500]

Re: Volvo Penta 2003 Cooling Result

Hi Michael, I have never felt the need for a separate sea water intake, I don’t know what would stop that barnicling up.
With the sail drive at least you have multiple intake holes.
On my 120s saildrive there is a hole at the bottom that you use to “rod” the sail drive water passage.

 

[<152587>]

I have a recollection that there is a restricter in the fresh water conversion kit for this very purpose but don’t see it in the parts list

Only on 2003 turbo version

 

[RichardS]

Re: Volvo Penta 2003 Cooling Result

Main water inlet is actually the hole under the nose of the drive and should be cleared on an annual basis

I think you'll find that the main inlet, certainly on Yanmar saildrives, is the multiple holed inlet at the rear end of the casting. The single inlet at the front on the bottom is narrower and follows a much more tortuous route involving two right-angles turns and is designed to provide cooling to the top end of the saildrive / gearbox.

Richard

 

[Tim 500]

Re: Volvo Penta 2003 Cooling Result

On the Volvo sail drive, the bottom hole is great for a vertical clearing rod, but is not a good water intake compared with the side holes.

 

[emandvee44]

Re: Volvo Penta 2003 Cooling Result

On the Volvo sail drive, the bottom hole is great for a vertical clearing rod, but is not a good water intake compared with the side holes.

When we were in Povoa for years the mussels loved the saildrive leg as a cosy home and the little ones grew rapidly during the season After haulout each year and after they had dried out, I used a steel rod through the bottom hole to break them up and the pieces exited from the hole.
I have always thought the side holes were inlets as they are shaped for inward water flow. This year is the first time there have been barnacles growing in the holes. Sorry I forgot to take pics. I will do so next time at the boat (long drive).

Cheers and thanks to all for your useful comments.

Michael.

 

[Bilgediver]

Re: Volvo Penta 2003 Cooling Result

Slight thread drift.
This Summer our boat spent much longer in the water than in previous years. We also spent a lot of time static, at anchor or in marinas.
Over the Summer I became convinced that the cooling water flow had diminished from what I remembered as normal. One indication of this was a change in the exhaust note. I also thought the engine was running hotter than normal (by touch on the cylinder head) , although no alarms.
In July I had the heat exchanger checked and rodded – it was fairly clean. At the same time I checked the jabsco pump and the impeller was perfect, but I took the opportunity to change it anyway.
We did very little motoring after July, but the perceived problem persisted.
We hauled out on 5^th. October, and I found what I think was the problem. There were several barnacles growing in the 6 saildrive intake apertures, which clearly would have restricted the water intake flow.
I am considering installing an alternative / additional through hull intake T’d into the saildrive seavalve/hose.

Any thoughts?

Thank you,

Michael.

This is a sensible mod and a few folk in our marina have done it following the failure of the leg mounted inlet valve which on some legs is the guys from a standard gate valve screwed into a valve like lower body machined in the leg. A right mixture of materials immersed in salt water.

 

[Tim 500]

Re: Volvo Penta 2003 Cooling Result

Excuse I’m still banging on about over cooling of my Volvo penta 2003 engine, it won’t get upto temperature even after an hour hard running.
I have newly fitted a Martec fresh water system, this constantly pumps cool water from the heat x into the cylinder head. There is no bypass operated by the bottom of the thermostat.
Anyone with in-depth knowledge of this conversion who can help?

Tim

 

[duncan99210]

Re: Volvo Penta 2003 Cooling Result

Has the actual engine temperature been checked using an infra red thermometer rather than an engine instrument which may be badly sited or not functioning properly? It may be that if the sensor is in the wrong place it's giving a lower reading than the actual temperature.

 

[jonrarit]

Re: Volvo Penta 2003 Cooling Result

Anyone with in-depth knowledge of this conversion who can help?

Hi Tim,

Not sure if this will help you but it might give you a clue.......

I have a raw water cooled VP2003. When I got it it had just been reconditioned so all the cooling channels were nice and clear. One problem was similar to yours in that it would not get up to full temp and only "warm" water from the calorifier.

The solution was simple. The cooling water flows from the pump through a "distribution" pipe, then round the engine, passed the thermostat and out to the exhaust. However there is a bypass pipe to allow water to pass through the exhaust (to keep it cool) until the thermostat opens.

The bypass pipe is at the rear of the engine coming out the cylinder head and into the side of the exhaust elbow. The internal diameter of this pipe is about 8mm (from memory). this was the problem as the cooling water was going straight from the pump, down the bypass tube and out the exhaust.

The solution was to put a restrictor "washer" at the end of the pipe (where it goes into the elbow) with a central hole of 2-3mm.

This allows enough water through to keep the exhaust cool while the engine heats up but forces the majority of water round the engine (and hot water system) which is in turn "regulated" by the thermostat.

Don't know if it will help you Tim but it worked for me. Engine comes up to temp quickly and loads of hot water.

Jonathan

PS - Yes I know in theory by forcing the water round the cooling channels it should cool the engine even more but the thermostat controls that flow hence it works for me.

PPS My guess is your conversion is very efficient and there is enough heat transfer going on from the water going straight out the bypass to keep your engine cool....too cool it would seem.

 

[Tim 500]

Re: Volvo Penta 2003 Cooling Result

Thank you for your thoughts.
As part of the fresh water conversion the pipe from the head to the exhaust manifold has been removed and holes plugged. It is not needed because all of the raw water goes into the exhaust elbow even when the thermostat is closed.
For Volvo supplied fresh water cooled versions of the engine there is bypass to divert fresh water to the pump, rather than through the heat exchanger. The Martec conversion does not have this bypass, so the only circulation around the engine when the thermostat is closed is via the gas hole in the thermostat!!
I have done some basic heat transfer calls for the heat exchanger and have concluded that it can dissipate 50% more heat than the engine will ever produce.
My conclusion is that as the engine circulation pump is still trying to pump into the engine that there is enough flow getting past the thermostat and though the heat ex to “well and truly” cool the engine.
I have added a bypass and expect this to do the trick, unfortunately the boat is now ashore for the winter so I can’t test it.

Tim