p4-33

Weeds are real bad this year in the Great Lakes. I guess we can thank the zebra mussels for cleaning the water so well...

I've got transom mounted raw water pickups, and I've had times when I've had a 4-course salad jamed in them. Burnt out an impeller last weekend, and constantly cleaning out the sea strainers.

Has anyone tried putting a coarse screen over the raw water pickup tubes on your transom? How did this affect your cooling at speed?

Also, what's your opinion on the best Sea Strainers? I believe mine are Perko, with a 2 1/2" x 6" long removable basket, round steel plate on top with a wing nut. They just seem whimpy for capacity. If I run over one floating weed bed, they're full.

Please don't suggest avoiding weeds, it's not easy.

Thanks,
Brian

Cord

I'd be concerned about the screen cavitating and the engine over heating from the airerated water. I don't remember who, but somebody offered a strainer that was supposed to be able to grind the debris up so it would eventually pass through.

Lmarth

I thought it was just me but yes it has been a bad year. I was out on Lake Ontario yesterday and have to negotiate a bay going out. I picked up seaweed going out and coming back. the flattened openings of my pickups are 1/4 by 2 inches. I didn't overheat. I saw the water temperature start to move, shifted to neutral, put it in reverse and goosed it a bit. Only other thing I've done in a situation like that was to immediately go on plane to force the weeds through. I've got racing sea strainers from Marine Machine. Covering the pickup opening with a screen might keep the sea strainers clean, but may block or reduce the flow of water to the raw water pump.

p4-33

Thanks guys, yeah my concern is also what a screen would do to normal water flow. My pick-up openings are about 1/2" by 1 3/4". I just spent tonight digging impacted seaweed out of the port side pick-up and flushing out the mess backwards. Then replaced the impeller, and dug out two vanes from my tranny cooler. Sucks.

I don't think throwing it in reverse would have helped this time. I try to check them whenever I putt in and out of some of the anchorages around here, and I emptied the strainers as well as felt the pick-ups with my feet while swimming around the boat. Nothing was there. When you're maneuvering around a hundred or so boats, you can't always pick the cleanest lane.

As soon as I started up on plane, I noticed the port temp climbing, and steam coming out of the exhaust. Strainers were full again! Emptying one helped, but not the port side. So I limped back to the launch, and once out of the water it looked like a head of lettuce hanging out of the port pick-up.

The macerator-type strainers sound intriguing. So what's all of that green stuff look like baked into the water passages of the block, and inside of the headers? I suppose green flow is better than none at all.

Sorry for venting, but these weeds are really getting old. It's getting to the point where I don't want to go to my favorite spots anymore, and the Mrs. ain't liking it very much. Maybe she needs to learn about strainers. Hmmmm....

Thanks again,
Brian

phughes69

I found this at west marine, but kind of expensive (1349.99 ea). Maybe it will give you an idea on modifying something else.

Groco Hydromatic Self-Cleaning 12V Raw Water Strainer
Forget about filter cleaning and leave it to Groco’s new self-cleaning strainer! Unlike passive filtration strainers, this strainer actually grinds and discharges debris, keeping water flowing freely to generators and air conditioners. One Hydromatic strainer will act as a sea chest, storing filtered water to be sent to water consumers such as air conditioners, heads and refrigeration systems.

User-selected periodic cleaning cycle
One-time manual override
Threaded 1 1/2" NPT inlet
Two 3/4" NPT and one 1/2" NPT outlet ports
13.5"H x 7.25"diameter

p4-33

Holy Chit! $1349.99 ea.? And of course, I need two. This is down the right track, but a couple of things concern me: 1) doesn't say anything about engine raw water, just air conditioning systems, gensets, heads, etc. 2) 1 1/2" inlet is nice, but outlet is only 3/4" NPT (x2). I don't think these would provide an adequate cooling supply to HP engines.

Thanks for looking.
Brian

Lmarth

p4-33--I agree with you. Sounds like they probably don't flow a lot.--Lou