Sand Ingestion - DP-SM

[Kosmofreeze]

Attempted to beach the boat the other day. Suffice it to say that it didn't work as planned and I sucked up a lot of sand in the process. Other than missing a little paint on the lower units, it doesn't appear that I'm any worse for the wear. Engine temps are running normal/normal since the incident so I'm not too worried about lasting damage. It got me wondering about how VP designs the water passages that diverts the solids or flushes them out. I'm sure I didn't do my rubber impeller any favors - but, it's due for replacement this year anyway. Is there anything I should look for when I drain the block and risers (winterization) to be sure all the ingested sand has been flushed from the system?

 

[Bondo]

Attempted to beach the boat the other day. Suffice it to say that it didn't work as planned and I sucked up a lot of sand in the process. Other than missing a little paint on the lower units, it doesn't appear that I'm any worse for the wear. Engine temps are running normal/normal since the incident so I'm not too worried about lasting damage. It got me wondering about how VP designs the water passages that diverts the solids or flushes them out. I'm sure I didn't do my rubber impeller any favors - but, it's due for replacement this year anyway. Is there anything I should look for when I drain the block and risers (winterization) to be sure all the ingested sand has been flushed from the system?

Ayuh,...... When you change the impeller, flush from there, backwards out to the drive,....
When you drain the block, pull the plugs, 'n any associated plumbing or hardware til yer looking at the cast iron holes, 'n probe 'em with a nail, or I use a 4" ssteel deck screw,....
If necessary, run it on the muffs for more flow,.....

 

[Scott Danforth]

do you have a heat exchanger, or are you raw water cooled.

1 of 3 things happen when you bury a VP drive in the sand.

• its light sand, the particles remain in suspension and most goes out the exhaust
• its heavy sand and the bottom of your raw water cooled block water jacket and exhaust manifold water jackets have a beach in them. or if you are heat exchanger cooled, you plug up the heat exchanger.
• its muck, you pushed 6 feet of muck up the suction line to the impeller. you are now trying to extrude hone the raw water pump, take out the impeller and overheat the engine. when you pull the suction line from the raw water pump to the power steering cooler, its packed full of muck

the last two require you to pull thing apart and flush

 

[Lou C]

IIRC there is a clean out on the SX upper unit, under the plastic cover. Once it gets in the engine it's tough to get it out. GM cast iron blocks were never meant to be raw water cooled, IMO. That's just the cheapness of engine marinizers.

 

[Kosmofreeze]

Mine is raw water cooled so no heat exchanger to plug up. I'm leery of using a hose to flush out any sand for fear of flooding the risers and getting water in cylinders. It's probably safe to flush backwards from the impeller inlet back to the drive ... I'll give that a go when I winterize. Appreciate all the good advise here.

 

[Bondo]

Mine is raw water cooled so no heat exchanger to plug up. I'm leery of using a hose to flush out any sand for fear of flooding the risers and getting water in cylinders. It's probably safe to flush backwards from the impeller inlet back to the drive ... I'll give that a go when I winterize. Appreciate all the good advise here.

Ayuh,..... There's little to no chance of that, with a good functioning system,.....
If yer that worried 'bout it, after doing so, pull the sparkplugs, 'n roll it over on the starter,...

 

[Scott Danforth]

As Bondo stated, there is virtually zero chance of flooding the risers

 

[Jeff J]

I pulled the exhaust off a Mercruiser a couple of years ago. There was zero chance the sand packed in there was coming out by flushing alone. It would take more water and pressure than the sea water pump can muster. A garden hose can’t move that much water.

 

[Scott Danforth]

A few years back I posted a few flushing nozzles that I made for going in the drain plugs

Basically this adapter and a section of 1/4" OD nylon tube



The natural curve of the tube helps to "aim" the flushing stream