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-   -   500 efi seawater pump (https://www.offshoreonly.com/forums/do-yourself-boating-budget/307043-500-efi-seawater-pump.html)

ldillow 01-04-2014 11:45 AM

500 efi seawater pump
 
Hi,
I am converting to a 500efi from a late model 502 mpi serpentine system.
I have everything except the sea water pump.
I kind of looks like I can use this the sea water pump off of the 502, it lines up but off just a little front to back. I was thinking of putting some spacers where the pump mounts to the bracket to solve the problem. Now I have someone that may need the pump because they want to buy my old blower setup and need to convert to serpentine system.

So here is my question. I am running a 565 around 1000hp. I figured the stock bravo, non-fuel pump, seawater pump would be adequate to feed the engine. I have a separate feed for the inter-cooler off of a separate Hull pickup and strainer.

So if I need a different pump, I was thinking the older 500efi pump (non-fuel pump version), or something after market.

So is my assumption that the single stock sea water pump is adequate for my needs?
If yes, does anyone have an older efi 500 seawater pump with bracket, pulley, etc, or know where I can get one?

Or is there a reasonably priced after market pump that would work with bracket, pulley, etc?

Thx
Larry

ldillow 01-04-2014 06:49 PM

must be a tough question!

ldillow 01-05-2014 01:31 PM

What do u use for a seawater pump?
There are probably a lot of 850hp plus motors out there?

Randy Nielsen 01-05-2014 03:25 PM

I don't think the waterpump will be an issue so long as the impeller & housing are in good shape, the bottleneck is the thru transom fitting. If you have an aftermarket thru hull pickup the issue would be too much pressure, in that case you will need a relief valve plumbed in to dump excess water pressure. Randy

ldillow 01-05-2014 04:21 PM

pressure
 
Why would too much pressure to the pump be an issue?
I also need to find a complete older style 500 efi pump with brackets and pulley, or a suitable aftermarket unit.
Thx
Larry

Randy Nielsen 01-05-2014 04:55 PM

Not too much pressure to the pump, but to the engine. It can cause gasket failure. My 650s have dump valves set to about 14psi on the output side of the waterpumps. Supposed to prevent pressure spikes from jumping wakes or waves when you re enter the water. The engine builder said he wouldn't honor any warranty claims related to cooling without them. Cheap insurance but probably not an issue with stock power otherwise merc would install them from the factory. There are waterpump set ups for sale all the time in the swap shop. Randy

ldillow 01-05-2014 05:30 PM

correct, bur i need the specific braket and pulley to match up with the rest of my 500efi serpentine setup.
i have been looking for 3 months and haven't found one yet

tcwcar 01-05-2014 06:09 PM

Larry my motors were 2000 500 efis, no fuel pump on the sea water pump, they are now 509s with whipples, I how I plumbed the pumps were from a transom pickup, to the sea strainer with a pressure relief valve, than to the pump, the intercoolers I plumbed from the pick up from the drives, to a strainer than to the intercoolers no pump. as far as fining some I would post WTB thread or look at ebay, I know if you have to buy it through Merc dealer its going to be $$$$ had to buy just a pulley it was $200/300 for it....

ldillow 01-05-2014 10:34 PM

pressure relief valve
 
I have never heard of using a pressure relief valve on the water feed? Can't find them on Teague site?
So you had yours before the pump and Randy had his after the pump. Where did u dump it to? Out a dump hole in the transom?
I had the stock 502mpi with the small SC with a Hull P/U and strainer..
Where can I see one of these?
Thx
Larry

Randy Nielsen 01-05-2014 11:10 PM

I'm sure Teague has them, I boat on pretty flat water so placement wasn't critical. If your leaving the water a lot & don't want to damage your strainers you can mount them in the strainers or the inlet side. I mounted my dumps next to my bilge outlets. You can get an aftermarket pump with bracket & just install your pulley, they have them like the older bronze pumps that are adjustable in the bracket but they are $$$. I can't believe it is that tough to find a pump/bracket assy that will work for your set up, p/s is a different story but not a waterpump. Randy


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