Offshoreonly.com - Run Dry Impleller Thought's???

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Well reading those other threads took the steam out of my sails for these... anyone run the Hardin housing I posted link to earlier though?

I can understand if you have a merc impeller there actually pretty good compared to a volvo...make no mistake volvo impeller's are complete crapola...Hmm yes complete crapola in my humble opinion. Actually the hope here is i get a impeller that wont blow up in a season or two, i do not run a high HP power plant that need's top end performance if you have ever seen a vovlo impleller in its housing you would understand the need for durability.

I used Global for years in motors and generator. Last twice as long.

Soooooo if you ran these dry for 15min what do you think the motor would be like?

Quote:

Originally Posted by Wildman_grafix (Post 4277906)

Soooooo if you ran these dry for 15min what do you think the motor would be like?

You could grill burgers on the risers...... now Im hungry....

All Marine EFI / MPI OEM engines using a 15 mins run dry impeller(s)s are not any better than the guardian mode your engine is going into from not seeing any water pressure and or overheat temps from the water temp sender reading and or the exhaust temp sensors readings.

When the ECM throws the engine into SLOW and or Guardian mode and the engine keeps getting hotter - next is engine shut down and or damage to a certain point.

To further the statement - while running as soon as your engine does not see water pressure - it goes into guardian mode on the spot. Water pressure is monitored in 80 % of EFI / MPI OEM marine engines from 2001 to current. In the past 10 or 11 years it is 100 % monitored and guardian protected. FYI.

i tried the blue ones a long time ago,they did not impress me.they did not move much water at idle and when running hard the water temp was going up.i chit canned them after a few weeks and went back to the merc ones.

I have heard the durometer is not as high as the Merc's and therefor do not create as much flow. Those of us already running on the edge of our cooling capacity might have an issue. I'm running a stainless housing that is hand polished and the Merc impellers seem to hold up pretty well, I also take them out at the end of the season when I winterize so they don't take a set. Going on my third season with the same impeller and I inspect them thoroughly for cracks and wear.

Quote:

Originally Posted by ThisIsLivin (Post 4278055)

are you saying you remove the impeller before storage and put that same impeller back in the following year?

Quote:

Originally Posted by BUP (Post 4277809)

FWIW years ago I remember I think Merc but not 100 % as someone in the industry did a volume water flow test against other aftermarket impellers. OEM Mercruiser Impellers flowed the most, Globe was below those numbers and some of the other aftermarkets impellers were worse at flow rates. I wish I had that info but do not anymore.

The but to this is everything has change as far as who is manu these as well compared to years ago. To bad there is not current testing numbers to see who has the best impeller flow rates for impellers.

I will say this for Volvo penta as Johnson makes their impellers and housings. it seems that a Jabsco impeller installed seems to flow more water and keeps the slightly engine cooler. FWIW.

Also impellers and housings are all about clearances and the correct tolerances to meet the volume / flow rates needed.

Have noticed the same, the Jabsco does flow more water then the Johnson & using the Globe run dry and pressures are same as the Mercs we've changed out.