Volvo Penta - Raw Water via seacock?

[MadMick]

1996 Parker 2510 MV with 2017 Penta 5.0 GXi w/Original 290 DP outdrive. Have had issues with clogging on raw water intake for 2 seasons and boat overheating. I like being shallow. Anyway I am now going to install a sea **** with scoop and strainer and bypass the outdrive intake.

Cooling water via the OD followed this path: OD to steering cooler to impeller to engine.

My question(s) are:

1. Since I’m installing a sea strainer should the raw water now follow this path: sea **** to strainer to steering cooler to impeller to engine?

OR

Sea **** to steering cooler to strainer to impeller to engine?

2. With original system did the raw water cool the OD as well? Is this something I overlooked?

3. Do I need to install back flow valves anywhere in the hose lines?

4. Will the impeller and pump be able to draw enough water while stationary with engine running?

5. How do I best cap off the original raw water hose to the OD?

Thanks in advance...

John

 

[Scott Danforth]

first, the 290 went away in 1989 to be replaced by the DP-A, then the A1, etc. (however i think they kept the 290 decals for a while after) your 1996 should be a DP-C

Second, if your shallow enough to draw in shells, the PS cooler has smaller passages than the inlet strainers, so the clogging is not in the drive, its the PS cooler you will still have that problem as most inlet strainers have holes bigger than the .190" ID in the PS cooler

Third, if you were running that shallow, you had your drive and the props in the muck if you have a raw water cooled engine, that muck that itsnt stuck in the PS cooler then settles in the block causing cooling issues

yes, you need to run your raw water thru the PS cooler, then the raw water pump, then the engine. you will have to go to an in-line PS cooler (like a 2 x 6" ), as the stock VP cooler bolts to the transom shield, holding the hose in place and seals the drive

No, there is no cooling benefit from the raw water going thru the drive

No need for added restriction of back flow valves

the raw water impeller moves enough water at idle while floating. the pump is primed because its below the water level. when you start to get on plane, the water pressure actually drops because the engine RPM is going high and the pump cant keep up initially, then while underway, the water pressure forces its way up the drive to aid in flow.

to cap off the water-inlet in the drive, you fire up the lathe and make a cap that fits the hose and hole like the original PS cooler. you can take the PS cooler and solder the end shut and re-install if you want or you can simply cap off the outlet with a double set of hose clamps on the cooler and a barbed plug.

 

[MadMick]

Wow, just Wow! Fantastic response Scott - plus thanks for fixing my attempt at a post.

1. You are probably correct regarding the info on the OD. No wonder I was having a hard time getting info on it.

2. The shallow water is in my slip and yes I put up OD when maneuvering in and out. Issues is/was, I believe and one I was not aware of until lately is that there is another raw water intake near the very bottom of the OD which I believe was the culprit as it was that much lower to the bottom and thinking I was high enough with my OD I was in fact not. Slip is all mud!

3. PS cooler. There is an inline cooler already in place. If I’m understanding you correctly I should replace it with the 2” x 6” you mentioned. The PS cooler I have is not bolted to the transom but in line on the intake hose from the OD that goes to the impeller so and forgive me but I’m still a little confused here.

4. I don’t know if you missed it but the other part of my post was where in the system I should connect the new sea strainer? Right after thru hull or after the PS cooler. In other words is it a. Or b?
a. Thru hull to strainer to PS cooler to impeller to engine
OR
b. Thru hull to PS cooler to strainer to impeller to engine

again I appreciate greatly the help!

best,

John

 

[Scott Danforth]

your missing the point I made.

the strainer doesnt really mater as the PS cooler has smaller holes, so that is your strainer all the rocks in the world will be stopped by the PS cooler long before the strainer catches them. you probably should pull the block plugs and flush out the sediment in the block too

the bottom pickup isnt the culprit, its you draging the drive thru the mud (which will eventually bite you with your props and the reverse lock-out mechanism)

btw, you need to plug the bottom pickup when you flush with muffs. you should get a factory manual it covers these things.

the plumbing path is pickup to PS cooler to raw water pump then to the rest of the motor

since you are bound and determined to add a sea-**** and strainer, you need a new PS cooler as your existing PS cooler will only fit where it is plumbed and there is no way to use it with your desire to use a seacock and inlet strainer.

make sure your new seacock forces water into the system while underway.

 

[MadMick]

Sorry Scott, I guess I did miss the point.