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5.7GSi strainer for raw water ?

C

cj270

Member
HI all,

I hope to run a year 2000 boat with two 5.7GSi motors coupled to SX drives in a lake.

Currently, I run a boat with an AQ170 and have had to install an inline raw water strainer because small pieces of plants and such like used to block the oil cooler.

I was wondering if I would need to install such strainers on the 5.7s as well.

Has anyone installed raw water strainers on a 5.7 ? if so, it would be a great help to know which brand and model of strainer they used.
 
A sea water strainer will only capture and hold so much marine growth before it becomes restricted.
Give it a try...... but I'd suggest staying out of the marine growth areas.
 
I've run varients of this scenario on Barnegat Bay which at times has a fair amount of "eel grass" a long stringy species of seaweed.

1) No strainer....
ate the oil cooler
2) Internal strainer with screw top and internal basket.... ( using thru drive pickup)
no oil cooler problems but required daily check to insure not clogged
also caused over heating problem when I did not notice that the gasket on the screw on cover got
damaged and allowed a vacuum leak at cruising speeds.

3) External wedge shaped scoop with built in strainer screen ( not removeable) using a thru hull pickup.
no oil cooler or heat exchanger problems
HOWEVER.... after a number of seasons there was hard marine growth inside the scoop that was not
cleanable without totally uninstalling scoop filter.

4) External wedge shaped scoop with removeable built in strainer screen using a thru hull pickup.
no oil cooler or heat exchange problems
this is first season with this, but if there is any junk growth inside the screen,
removing the screen is just removing 4 nylon screws.

Adding the thru hull pickup for the external filter allowed me to plumb in a very easy fresh water flush/ winterizing port just downstream from the 1/4 shut off valve.


The above 4 scenarios span over 40 seasons of boat ownership/operation and 4 sterndrive boats, 3 with volvos.
 
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I used the wedge shaped cover over the air conditioner pickup.It needed to be taken off and painted "inside" as often as the outside(hull).
I also added Cayane Pepper flakes to the paint.Seemed to work?
I installed it with the flow of the hull and had no problems with anything.Installing it with the flow,makes it streamlined and everything slides off.
I originally installed it for the jellies.They'd get sucked up into the cooling and clog it.(usually in the middle of the night)
 
Hi All many thanks for your input !!
This boat will be used very infrequently and will be stored on trailer indoors when not in use.

I might try using the internal strainer with basket. I would appreciate any hints on which particular one to use
 
If the 5.7L boat has Power Assist steering, there will be an oil cooler in the sea water path. These are generally fist in line.
If you do install a sea water strainer, you may want to re-configure this so that the strainer is up stream of any oil cooler.


.
 
cj270 said:
Hi All many thanks for your input !!
This boat will be used very infrequently and will be stored on trailer indoors when not in use.

I might try using the internal strainer with basket. I would appreciate any hints on which particular one to use
Click to expand...

Basically, there are three designs out there.

1) 100% Plastic.... not for me, I'm nervous about plastic in the engine system.

2) Bronze with glass or plastic cylinder with internal basket and screw-in top.
I've used this one and you need to be careful to maintain the gasket on the top and to avoid cross threading the top when reinstalling. Cross threading likely to be a bigger issue these days as the one I used many years ago had a bronze top while it appears in photos that the new ones have a plastic cap.

3)Bronze with glass or plastic cylinder with internal basket and screw-DOWN ( via two wing nuts as clamps) top.
I've run boats with this strainer. The issue is that if the two hold down nuts are not tightened carefully ( for example one side is tightened before the other!), then the top does not sit square and seal correctly causing a vacuum leak and overheating. Also... gasket needs regular attention.

Pick the one you think you can live with. As noted previously, I went with a cleanable external wedge type.
 
Sandkicker on what motor did you run those different strainers ? Im wondering what hose size I should buy for the VP 5.7
My boat is still on its way to Sri Lanka from USA so I have no way to check yet and I would like to order the strainers now so they get here with or before the boat.
 
cj270 said:
Sandkicker on what motor did you run those different strainers ? Im wondering what hose size I should buy for the VP 5.7
My boat is still on its way to Sri Lanka from USA so I have no way to check yet and I would like to order the strainers now so they get here with or before the boat.
Click to expand...


.....2) Internal strainer with screw top and internal basket.... ( using thru drive pickup)

This was on a 185HP/ 283 CID block Chevy ( Chriscraft Thermodevcon).

Also forgot, same strainer as above, but with a standard "high speed" thru hull pickup on the Chrysler 225 HP 318CID FWC with thru transom/mufflers that replaced the 283 Chevy.


3) External wedge shaped scoop with built in strainer screen ( not removeable) using a thru hull pickup.
no oil cooler or heat exchanger problems
HOWEVER.... after a number of seasons there was hard marine growth inside the scoop that was not
cleanable without totally uninstalling scoop filter.

This was on a 260 HP 5.7 MERC MIE

4) External wedge shaped scoop with removeable built in strainer screen using a thru hull pickup.
no oil cooler or heat exchange problems
this is first season with this, but if there is any junk growth inside the screen,
removing the screen is just removing 4 nylon screws.

This was on a 260 HP 5.7 MERC MIE

5.7/350 CID engines, regardless of who does the conversion, i.e. MERC or Volvo specify a 1-1/4" dia hose, min. Since this hose is on the "suction side" needs to be wire reinforced.
 
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