Run-Dry Impellers

Does anybody have any experience with Globe Marine Products Run-Dry impeller?

Per the website:

Tests prove that Globe’s Run-Dry® impellers outperform standard neoprene or rubber impellers and are guaranteed to run-dry for up to 15 minutes.

I need a spare impeller and I was considering a Run-Dry...

JQ

What do you think will happen in the engine compartment when all that heat being generated has no place to go for 15 minutes?

Best case scenario, virtually all the hoses are completely melted. The exhaust manifolds are cracked and useless. I would guess that the block and/or heads are also cracked and there could very well be some fiberglass on the engine cover or the bilge that has started melting.

Worst case scenario, a fire sends the boat to the bottom of the lake after the heat buildup ignites something under the engine cover.

Just because you have an impeller that can run dry for 15 minutes doesn't mean that anything else in that engine compartment can run dry for 15 minutes.

Let us know how that works out for you.

There's many times where it'd be convenient to make sure the fuel system is fully primed without having to hook up the hoses and bucket etc. Rolling the engine over for 45 seconds would be nice but don't because of unnescessay stress on impeller.

Gents:

Perhaps you have misinterpreted the purpose of my question. By no means am I advocating that I, or anyone else, should purposely run the raw-water pump dry. However, there are some obvious benefits to have an impeller that is less prone to failure in the event of a problem.

I am looking for anyone who has experience with these impellers under normal service. Do they hold-up like the OEM impellers? In the event of a problem, have they performed as advertised?

The bottom line is that every time I launch my boat from the trailer, the impeller has to run for a few moments "dry" as it sucks water through the hose, through the strainer, through the transmission cooler and finally into the raw-water pump. I realize that there may be some residual water in the hose, but perhaps this new style impeller is a better way to go in the long run.

JQ

Gary S wrote: I had one when they were under the Barco name. I felt it wore faster than a oem. The tips of the vane's and the sides of the impeller were not smooth after it ran for awhile. Back when there were more inboards on the market ie the 80's, they went out of business. If you look at how PCM ran their hoses you can see that there is enough water left in the hoses when shut off to protect the impeller before external water gets to the pump. I feel if these impellers were what they claim to be the OEM' would jump on it. The fact that they have not says something.

Thanks, Gary. That's what I was looking for.

JQ

Rob don't get me wrong it did work and if they were the only thing available I'd use them. It just that the oem Sherwoods are readily available along with the Jabsco's in the Mustang. I have never had one gone bad,some years I don't even remove them.

But Pete, Do you use your boat twice a day, every day during ski season?

8122pbrainard wrote: Jonny Quest wrote: The bottom line is that every time I launch my boat from the trailer, the impeller has to run for a few moments "dry" as it sucks water through the hose, through the strainer, through the transmission cooler and finally into the raw-water pump. I realize that there may be some residual water in the hose, but perhaps this new style impeller is a better way to go in the long run. JQ You answered your own concern. The impeller doesn't run dry due to the residual water.

I've owned my current SNOB for 6 years. The previous owner is a close friend and was the original owner. I purchased the boat from him when he moved away. He told me that he would change out the impeller ever 2 years. He also claimed that the engine was only operated with a water source. I believe him. In the glove box was a "spare" impeller that my friend had saved from the previous change-out. It looked reasonably good, just the normal curved vanes.

When I did my first impeller change-out, the impeller was in pretty bad shape. Small chunks of impeller vanes were missing. I couldn't determine if the impeller condition was due to dry running or not. The impeller was only 2 years old, so I'm trying to avoid any similar problems.

Can an air-bleed or air leak cause impeller failure? I did discover that the there was a crack in the strainer housing that would have allowed air into the system. That has since been corrected with a new Sherwood strainer.

JQ