Global Impellers

[Scuffy]

I had someone recommend using these impellers. They claim to be able to be run dry for 15 minutes without damage. I wondered if anyone here had any experience with them? I have filled out an information form looking for additional info about which to use in our D3. I'll ask the authorized Volvo Penta dealer what he thinks and how this might effect the engines warranty. He is a link if anyone is interested. http://www.globecomposite.com/Marine_Products
D.D.

 

[dialtone]

Let us know what info you get back, sounds better than fishing out pieces

 

[SGIDAVE]

I'm running a GLOBE impeller (blue one) in my Yanmar powered 21EC.

I ordered mine on Amazon.com. They shipped the wrong item number. It came direct from Globe; I called and then sent the correct one right out. They didn't want the wrong one back.

Anyway, seems to work. I haven't tested the "run dry" claims 😉

dave

 

[cutwater4me]

We used Globe Blue impellers on our 10 KW Northern Lights Gen on our 43 Nordhavn. They are bulletproof!
Our old impellers were good for one season and that's it. When we switched to the blue impellers from Globe they lasted for many, many years and we changed it out just out of fear it might go bad!

 

[dialtone]

Did you see the drive saver on that website? Seems very useful.

 

[knotflying]

We used Globe Blue impellers on our 10 KW Northern Lights Gen on our 43 Nordhavn. They are bulletproof!
Our old impellers were good for one season and that's it. When we switched to the blue impellers from Globe they lasted for many, many years and we changed it out just out of fear it might go bad!

That was my question. I change my impeller at 250 hours. Since I am checking it, I change it because I am halfway there on a tough job to begin with. If I were to go with a Globe impeller I am wondering how much longer past 250 hours I could wait before I had to check it. The price is close to double. Could I wait until 500 hours to check it?

 

[Scuffy]

The people I have talked to point to the Global impellors lasting at least quite a bit longer than standard impellors. I think someone said Volvo had a 400 hour interval for impellor changes. It's my thinking that there would be less chance of a blade breaking off because of the material Global uses. Some one told me that in a Yanmar engine if pieces of the impellor get into the engine they have to pull the engine to remove them. I don't know if Volvo engines are any different in that respect. I like the idea of the Global impellors and will probably install one when the time comes. I guess if your impellor is getting worn your engine temp would show that to some extent? I'm thinking folks that run in shallower water and Captain Runarounds would have a better chance of sucking in more sand and grit which I would think would speed up impellor wear. Just my thoughts and opinion here. Your thoughts?

 

[PhilR]

Does anyone have the Global part # for the Yanmar 4BY2- 180 impeller ?

 

[nzfisher]

Last time I looked for this sort of thing there was no impeller for the 4by engine. I hope that has changed. I would love to have a more fool proof impeller as having one clogged while offshore is one of my big fears. As for getting the pieces of the old impeller out this can be done without taking the engine apart. I think there is a description of this in the history. If not, PM me and I can describe how it can be done (I got back 95% of the parts on the "reconstructed impeller" and probably all of them just some where lost in the process).

 

[knotflying]

You can go on the global site and cross reference the number to replace the Johnson impeller.

 

[baz]

I had someone recommend using these impellers. They claim to be able to be run dry for 15 minutes without damage. I wondered if anyone here had any experience with them? I have filled out an information form looking for additional info about which to use in our D3. I'll ask the authorized Volvo Penta dealer what he thinks and how this might effect the engines warranty. He is a link if anyone is interested. http://www.globecomposite.com/Marine_Products
D.D.

Hmmmm, 15 minutes... and then what ? Does this mean at 15:01 the impeller melts, disintegrates and flies into pieces ? 😱

My question here is.... if raw water to the impeller stops just how long will it be before the engine sensor kicks out an alarm ? I would hope it's less than 15 mins.

 

[SGIDAVE]

I had someone recommend using these impellers. They claim to be able to be run dry for 15 minutes without damage. I wondered if anyone here had any experience with them? I have filled out an information form looking for additional info about which to use in our D3. I'll ask the authorized Volvo Penta dealer what he thinks and how this might effect the engines warranty. He is a link if anyone is interested. http://www.globecomposite.com/Marine_Products
D.D.

Hmmmm, 15 minutes... and then what ? Does this mean at 15:01 the impeller melts, disintegrates and flies into pieces ? 😱

My question here is.... if raw water to the impeller stops just how long will it be before the engine sensor kicks out an alarm ? I would hope it's less than 15 mins.

Your question I highlighted above has resulted in MANY discussions on Tugnuts about exhaust temp and cooling water flow sensors/alarms. The problem, in the standard set up, is that the NEXT thing to happen after your raw water flow stops is the engine will overheat. Or the exhaust melts and/or catches fire. The actual sequence of events depends some on your level of awareness. I don't watch my exhaust water flow much once I have started the engine and established that there IS cooling water flow (i.e., usual quantities of water being ejected with the exhaust gases).

Rather than the impeller stopping, it will likely continue running "dry" when something stops the flow of cooling water...a grocery bag, jelly fish, or seaweed gets sucked into the raw water intake effectively blocking it. If this happens while you are motoring away from the ramp at idle speeds, it may be 10-15 minutes before the engine overheats and gives you an alarm. By then, the raw water impeller will be shredded and its pieces sent downstream into the cooling system once raw water flow is re-started. If you were running faster when the blockage occurred, then presumably the overheat alarm would come on faster due to the higher engine speed. Nasty scenario.

Please realize this is the standard way of installing a marine engine; Ranger is using customary installation practice. It's up to the owner/operator to make it better if he/she so chooses.

Aqualarm makes numerous sensors to address this situation. Most applicable are their cooling water flow sensors and exhaust temp alarms. Having both would be a "belt AND suspenders" approach for those so inclined. I'm not endorsing Aqualarm...there are other brands of sensors.

Another way to prolong the time your impeller can run dry, aside from using the GLOBE impeller, is to install a Speedseal product. Look here (http://www.speedseal.com/speedseal.html) for information. Again, no material interest in this product, just sharing info about something useful.

That was the long answer to your question...The short answer, Barry, is that the same thing will happen as would have with your last boat.


dave

 

[baz]

On my R-25 I had the Garmin setup to trigger an alarm if coolant temp got a few ºF above its normal operating temp of around 190 ºF if I recall. My assumption here was that if the impeller failed or the raw water pickup grate was blocked the coolant temp would rise quite rapidly above its normal range.

This is why I'm so adamant about having the engine data displayed on my R-21EC's Garmin 741XS via the NMEA 2K Gateway device. The coolant temp can then be observed on the MFD and a suitable alarm set for when the coolant temp rises above its normal temp range.

 

[SGIDAVE]

On my R-25 I had the Garmin setup to trigger an alarm if coolant temp got a few ºF above its normal operating temp of around 190 ºF if I recall. My assumption here was that if the impeller failed or the raw water pickup grate was blocked the coolant temp would rise quite rapidly above its normal range.

This is why I'm so adamant about having the engine data displayed on my R-21EC's Garmin 741XS via the NMEA 2K Gateway device. The coolant temp can then be observed on the MFD and a suitable alarm set for when the coolant temp rises above its normal temp range.

I don't think that will save you from a shredded impeller. I have the cooling water sensor and it alarms IMMEDIATELY when the water flow stops. Long before any overheat or even 'rise' above normal operating temp. While your idea is a good one, it won't help when the cooling water obstruction occurs RIGHT AFTER starting the boat. Sometimes theres trash floating around at the ramp, and if the obstruction occurs just after getting underway, your engine likely has not reached 'normal' temps, so having the alarm go off sometime later means you've run your impeller dry for...how long? Five, 8, 10, or more minutes. Not good. Get a flow alarm...you'll be more relaxed. 😉

dave

 

[baz]

Dave: As always.... you give good advice. Thanks. 🙂

 

[Scuffy]

Baz,
If you use the link in the original post, get there and then click contact us, support and type in your question. They might take a few days but they will report back with what impellor to order for your engine

 

[SGIDAVE]

The Yanmar 3YM30 engine takes the GLOBE 331M impeller.

dave

 

[captstu]

Dave, What "cooling sensor" did you install?

Just as you reported, my muffler and some hoses melted when the impeller failed for a few seconds. The overheat alarm in the circulating water (antifreeze) system did not show an increase when the failure occured.

I have a new manifold sensor but haven't figured how to get a wire up front - or how to get switched 12V so I can put the alarm in the back. Since you have done it. I sure appreciate the help.

Did you use the Yanmar raw water overtemperature sensor? If so, does an alarm sound when cooling water fails, or just the gauge you don't happen to be staring at go up.

Thanks much. /Stu

 

[SGIDAVE]

Dave, What "cooling sensor" did you install?

Just as you reported, my muffler and some hoses melted when the impeller failed for a few seconds. The overheat alarm in the circulating water (antifreeze) system did not show an increase when the failure occured.

I have a new manifold sensor but haven't figured how to get a wire up front - or how to get switched 12V so I can put the alarm in the back. Since you have done it. I sure appreciate the help.

Did you use the Yanmar raw water overtemperature sensor? If so, does an alarm sound when cooling water fails, or just the gauge you don't happen to be staring at go up.

Thanks much. /Stu

Hello Stu,

Glad to hear you've got the right muffler.

I installed the Aqualarm cooling water flow sensor as sold from Defender. It comes with the flow sensor, the alarm and a dash light as shown here

This (http://www.defender.com/product.jsp?pat ... &id=744093) is the link to the kit which is for raw water hoses ½ - ¾" inside diameter. I'm sure your larger tug uses larger raw water hose, right? Defender.com sells a kit for 1"-1.25" hose size.

I used 'fishing' sticks to assist with running the wires forward to the helm. Like these - available at Lowes, Home Despot, etc

The switched 12VDC source which I used was off the ignition switch.

I like your idea to use the exhaust temp alarm too as you will have ALL bases covered. The cooling water flow sensor alarms IMMEDIATELY when raw water flow STOPS. In a "low flow" condition, however, I doubt it will alarm even though the exhaust gas temps may rise to dangerous levels.

I did NOT use any Yanmar sensors - only the Aqualarm thingy.

Alternatively, Aqualarm.net sells a single 'panel' which incorporates BOTH water flow and exhaust temp alarms

Also note I have the 21EC so my installation is probably FAR more straightforward than on your R25 where engine access and wire runs toward the helm may be more difficult. But I don't know about that - let us know.

dave

 

[captstu]

Dave, Great photographs. I have the temp sensor - I'll order the dual indicator you picture and pick up a snake from Lowes. Once I grow an extra set of hands, it should be easy.

Any tricking to cutting the oval hole? My bits are all round 🙂

/Stu