VP D2 55 - Rydlyme circuit to clean raw water passageways

[MagicalArmchair]

On my old boat, Triola, her hardy Yanmar 2GM20 was 20 years old and had built up lots of deposits that I wanted to get rid of, so I figured out how I would run Rydlyme through her engine and wrote it up in the below.

Clean the raw water passages on your engine with Rydlyme - Triola - Albin Ballad #50

Mirage has a VP D2 55 that was original equipment to the boat in 2002. She has only been mine for the best part of a year and I want to give the engine a good service this year. How would I run Rydlyme through this engine? Unlike my raw water, directly cooled 2GM, the D2 55 uses indirect cooling through the heat exchanger - I presume this guy will need to come off to be cleaned out? Or I suppose this would be on my pumped circuit of the Rydlyme?

 

[pvb]

Does your engine ever show any signs of overheating? If not, I'd leave the heat exchanger alone for now.

 

[PaulRainbow]

Bucket of Rydlyme, submersible pump in the bucket, pipe from pump to the raw water pump outlet hose (or where that hose connects to the engine. Remove the pipe from the outlet of the heat exchanger and add a longer pipe going back to the bucket. Switch pump on, leave running for an hour or three.

 

[pvb]

Bucket of Rydlyme, submersible pump in the bucket, pipe from pump to the raw water pump outlet hose (or where that hose connects to the engine. Remove the pipe from the outlet of the heat exchanger and add a longer pipe going back to the bucket. Switch pump on, leave running for an hour or three.

But does it need it?

 

[wully1]

I’ve just (hopefully) cleaned out my VP 2030 cooling circuit with a similar product. I drained the coolant from the lowest point I could - the block drain plug had been rounded off by some previous incompetent numpty- and re filled with the treatment given to me by a central heating engineer.
Left it to soak and will drain , refill and test once Im back in the water next week.

 

[MagicalArmchair]

But does it need it?

Thanks for the responses, and nope, it never shows signs of overheating so I am likely, as usual, over thinking it. The engine is as sweet as a nut. My intent is to keep it that way through preventative maintenance... however, this may be one job I can dodge this year (I do have rather a long list of other things that really do need doing).

Bucket of Rydlyme, submersible pump in the bucket, pipe from pump to the raw water pump outlet hose (or where that hose connects to the engine. Remove the pipe from the outlet of the heat exchanger and add a longer pipe going back to the bucket. Switch pump on, leave running for an hour or three.

Thanks for the circuit Paul, I've added that to my notes and when I get the will and time to fiddle, I'll do that. Another one I might do is the exhaust elbow - after 20 years I may be on borrowed time... as pvb notes, this may not need doing at all either... there have been some horror stories though...

 

[RJJ]

Thanks for the responses, and nope, it never shows signs of overheating so I am likely, as usual, over thinking it. The engine is as sweet as a nut. My intent is to keep it that way through preventative maintenance... however, this may be one job I can dodge this year (I do have rather a long list of other things that really do need doing).



Thanks for the circuit Paul, I've added that to my notes and when I get the will and time to fiddle, I'll do that. Another one I might do is the exhaust elbow - after 20 years I may be on borrowed time... as pvb notes, this may not need doing at all either... there have been some horror stories though...

Thinking of doing same...also D2 55. But I am always confused about the thermostat. If you run a circuit with an electric pump as described above, isn't there a problem bypassing the heat exchanger if the engine's cold?

 

[duncan99210]

Not if you’re only treating the raw water circuit through the heat exchanger: that’s an open circuit, no thermostat.

 

[ip485]

Yup did mine more preventative exactly as Paulr describes albeit different engines. Lots of frothing and very dirty water and hopefully reset the clock on this maintence job, and the engine seemed to run maybe slightly cooler.

 

[MagicalArmchair]

How many litres of Rydlyme did you use to rinse through your engine? Will a couple of litres do it on a D2-55?

https://www.rydlymemarine.com/wp-content/uploads/2019/12/Inboard_intructions_0917.pdf

 

[PaulRainbow]

How many litres of Rydlyme did you use to rinse through your engine? Will a couple of litres do it on a D2-55?

https://www.rydlymemarine.com/wp-content/uploads/2019/12/Inboard_intructions_0917.pdf

They say mix 50:50, so 2 litres of water and 2 litres of Rydlyme in a bucket. Should be enough for your engine.

 

[MagicalArmchair]

Thanks Paul, very kind. I'll order the slop.

 

[kacecar]

I'm planning a similar job on my raw water cooled (no heat exchanger) VP2003 but have a question - apologies for slightly diverting/extending the thread.

First I'll remove the thermostat, then I'll put the solution into the block as per Paul Rainbow's instructions (raw water pump outlet hose). But where should I connect the exit hose (the one back to the bucket and pump)? The lowest drain point appears to be the drain tap (currently blocked by sludge hence the desire to flush the system). Other options are from the exhaust elbow itself, the exit from the cylinder head at the back of the engine, and the exit from the calorifier circuit. Which one should I use?

 

[PaulRainbow]

I'm planning a similar job on my raw water cooled (no heat exchanger) VP2003 but have a question - apologies for slightly diverting/extending the thread.

First I'll remove the thermostat, then I'll put the solution into the block as per Paul Rainbow's instructions (raw water pump outlet hose). But where should I connect the exit hose (the one back to the bucket and pump)? The lowest drain point appears to be the drain tap (currently blocked by sludge hence the desire to flush the system). Other options are from the exhaust elbow itself, the exit from the cylinder head at the back of the engine, and the exit from the calorifier circuit. Which one should I use?

The raw water pump hose is the first point of the cooling system, so you want to exit the system at the last possible point, so you clean as much of the system as possible. The exhaust elbow would the the last possible place.

 

[VicS]

I'm planning a similar job on my raw water cooled (no heat exchanger) VP2003 but have a question - apologies for slightly diverting/extending the thread.

First I'll remove the thermostat, then I'll put the solution into the block as per Paul Rainbow's instructions (raw water pump outlet hose). But where should I connect the exit hose (the one back to the bucket and pump)? The lowest drain point appears to be the drain tap (currently blocked by sludge hence the desire to flush the system). Other options are from the exhaust elbow itself, the exit from the cylinder head at the back of the engine, and the exit from the calorifier circuit. Which one should I use?

Yes remove the thermostat.

I think if you use the connection on the back of the head as the outlet the cleaning solution will do little more than flow the length of the distribution pipe and out again.

I dont know how the calorifier is plumbed in but I would allow some to flow out via that route just the give the calorifier a flush.

The cylinder block drain would be good place to allow a good flow to ensure that the block is well flushed.

Otherwise let it flow out via the "elbow". If you can clamp the hose coming out of the back of the head it would ensure that there is a good flow though the engine rather than just down the distribution pipe.

I would allow a little to flow out of all available points and check it for acid presence using some universal pH testing paper The picture below shows what I have.

The process will be slow in the cold. It will be much quicker and more effective if you can warm it up little. That's the advantage of running the engine and using the engine cooling water pump to circulate the solution.

 

[kacecar]

Thanks Paul and VicS for those pointers. I won't be able to do this with the engine running so, clearly, a bit of patience is going to be required - I think I'll try the elbow first and, if necessary, drain point second.

 

[VicS]

Thanks Paul and VicS for those pointers. I won't be able to do this with the engine running so, clearly, a bit of patience is going to be required - I think I'll try the elbow first and, if necessary, drain point second.

Definitely run some out of the drain cock while you are circulating it ,
I am not sure how well the cleaning solution will circulate round the cylinder block with no heating from the running engine.

 

[PaulRainbow]

Definitely run some out of the drain cock while you are circulating it ,
I am not sure how well the cleaning solution will circulate round the cylinder block with no heating from the running engine.

Why does it need heat to circulate ? I've never, ever had the engine running to use Rydlyme, to do so would be madness, which is no doubt why Rydlyme don't suggest doing it.

The solution has to be pumped for between 1 and 4 hours, how hot do you suppose the engine will get in that time, red hot, white hot, or seized solid ?

With the solution being circulated and not going out through the exhaust, the exhaust hose and or silencer/water lock etc will almost certainly be destroyed.

I'm guessing you haven't ever used Rydlyme.

 

[PaulRainbow]

Thanks Paul and VicS for those pointers. I won't be able to do this with the engine running so, clearly, a bit of patience is going to be required - I think I'll try the elbow first and, if necessary, drain point second.

Do NOT run the engine, that's a ridiculous suggestion.

Connect from the elbow to the bucket and leave the pump running until the solution stops fizzing. That's 1-4 hours.

A cheap pond pump works well for this job.

 

[ip485]

I agree.

I might be careful with the calorifier. It is possible there could be a lot more deposits in the coil than you realise. The Rydlyme will reveal any weakness and it is possible the calorifier will leak, rather like an old kettle descaled. If the rest of the engine is cleared leaving out the calorifier not much of the lime will dissolve back into solution. BTW its just an observation that you might end up with a leak.