I Second Groco
Yesiree - there's simply NO comparision between the Groco centrifical vane-type pumps and most all the soft rubber impeller-type pumps being offered as "Washdown" pumps. The vane-type will always develop more head pressure. And volume too for that matter. Always. Much more so than any of the common rubber impeller jobbies. Hard vanes vrs soft rubber blades ain't much of a contest, frankly.
There are two ways to go here with the Groco.
1/ My easy way - I use the Model SPO-60-N which is the simple pump only - no fancy pressure-sensing valve to get screwed up.
2/ The other way - Groco also makes a nice complete pump-and-pressure-valve rig that they factory-mount to a piece of Lexan for installing in your bilge as a system. If you use this setup - you can use a regular on/off lever-trigger garden hose nozzle.
Either way works - but there are a few facts about these pumps that you need to know prior to installing.
a/ These pumps freakin' HATE backpressure - they develop SO much pressure that the water can force its way past those super hi-tech carbon-faced seals in the pump body if there's too much backpressure on the water's exhaust - therefore if you go for the "Lep's simplified method" you cannot use a normal garden hose-type spray nozzle to regulate the water flow in an on/off manner without risking a blowout of those carbon seals. That water can and will spray up towards the electric motor and that as a rule ain't healthy for the pump. So what I use is an "Always on" brass needle-spray nozzle that I bought in Home Depot's Garden dept for $3 - I then regulate the "On and Off" of the water stream with a electric push-pull switch mounted to my bulkhead. Simple and fool-proof.
b/ These pumps are quite the power hogs and demand a good deal more current than any Sureflo or Jabsco Water Puppy. Bigger motor = more current needed = more torque to turn the vane assembly = longer life & more water pressure, provided you feed it the current it wants and needs. If you supply insufficient amperage at the pump motor, it will overheat and fail in a relatively short time. No different than any other current-starved electrical device.
You will need to install the pump either RIGHT next to your battery or power-feed junction plate to keep the wire runs short and thus keep resistance low (And that includes the wiring to & from the on/off switch). OR do as I do, use a quality marine solenoid rigged with no less than 8-gauge wire (6 is better) to/from the battery and then you can use thin 14-gauge wire from the push-pull to/from the solenoid. Cole-Hersey Corp. makes an appropriate marine solenoid that's properly protected from the environment (And shielded from potential sparking)for this app. I've had mine down in my very wet Shamrock bilge for 7 seasons now with no sign of failure or corrosion. (See my comments that follow regarding pump-motor painting - point "F".)
c/ Use no less than 5/8" I.D. hose for these pumps. I use 20' of the clear criss-cross red-fiber-reinforced vinyl hose that Home Depot sells for a fraction of what the marine chandleries get.
d/ I have my pump plumbed to a "Y" with each leg of the "Y" having it's own shut-off valve. The "Y" is screwed to a thru-bulkhead hose fixture and is a yellow plastic piece and also from the Home Depot garden dept. One leg goes to the afore-mentioned washdown hose and the other goes to another hose that runs under my port-side gun'nel all the way back to the transom and then thru it (Via some bronze thru-bulkhead marine fittings) and into my 162 Igloo, which is semi-permanently mounted to my swim platform. This plumbing setup does two good things for me: 1/ It turns the Igloo into a smokin' bunker/herring bait tub and more importantly for a guy that like blackfishing as much as I do, 2/ it allows me to wash those slimey fish down nicely during the run back to the dock - nice clean fish for the fillet table or photos. A Godsend for douching down a couple of limits of gurvey tog before they slip-slide across the fillet table back at the dock. I cut a hole in my Igloo and installed a 1.5" bronze thru-hull about 3/4 of the way up from the bottom - this allows the yucchy gurve-water to rise to that level and then run out the back of the cooler.
e/ One of the guys above asked about using it as bilge pump - and yep - I have mine plumbed to a thru hull that has a plug on the side - If I hole the boat's hull, I pull the plug and throw the hose overboard minus the nozzle and I've got a 4th bilge pump running. More pump capacity is definitely better there, I think that's pretty tough to argue against. And I also have that brass spray nozzle on a brass quick-release chuck - in case of main engine RW pump failure, I can plug that Groco right into my RW pickup via a plumbed-in brass receiver and continue merrily on my way.
Guys that own single-screw boats that fish offshore late in the season have to think of this stuff in advance so that if bad poop happens, we're prepared.
f/ Regardless of whichever brand of pump you buy, do yourself a favor and give the motor housing two thick coats of Rustoleum and allow each coat to dry thoroughly before installing. I've yet to see ANY pump brand not heavily rust in a wet bilge area after a few seasons.
If you are replacing a Sureflo pump with this Groco - you will be Shocked at just how much more powerful the Groco really is. The guys above were not exaggerating - it'll take dried clam chum or Mackeral blood/scales right out of the glass. Mine is fully capable of firing a high-pressure stream 3/4 of the way across my canal and I've used it more than once to discourage jet skiers from climbing up my ass when running up the bay. They just hate that.
Sureflos? I consider those things "Disposo-pumps" - if you are lucky you can get a season or so out of them. And as far as pressure - I can pee-pee further than those things can, and I ain't a young man anymore.
Well that might be a SLIGHT exaggeration, come to think of it.
(This post edited by Leprechaun on 01/10/2005)