A27FC Overheating not cooling system related?

[JT48348]

This thread still makes me chuckle. Clearly your over heating issue could be caused by the Farsenberg Effect in a semi-tropical climate ......or.....it could be a problem with the cooling system! Lol

If ur diver is "poking holes" in the raw water strainer you got problems.....with the cooling system! Lol. Here's some examples of the problem:

http://www.pbase.com/mainecruising/external_strainers

[rnummi]

Thanks JT... the reference addresses my issue perfectly. I have the "@&$$ strainer that's a one piece. Internal hoses were replaced by Don when he mounted the Groco 1000. Took her out yesterday and ran 3800 rpm for about 5 miles at 8.2 knots. Temp slowly started to creep up past 190. Got the buzzer at 200 and immediately backed down. Temp fell to 180 within 1 minute of backing down. I can cruise all day at 3500 rpm and 180 degrees at 6 knots. Reiterating previous posts, all new hoses, new impeller, newly reconditioned heat exchanger and oil cooler...... gotta be micro barnacles in the strainer intake. When she comes out that's the first thing going away.

[tego]

Rick, Howdy again. I had the same problem on a boat many years ago. I'd just close the seacock, pull off the hose, put my hand over the top of the seacock, open the seacock and stick a large screwdriver down between the fingers and scrape the inside of the strainer surface, pull my hand off quickly to flush the crud out and reclose the seacock, replace the hose and we're back in business. Takes about 3-5 minutes. Ben

[Beta Don]

The slits in the bronze strainer which covers the engine intake thru hull are pretty narrow. If you paint over it with a roller when doing your bottom job, you will really reduce the amount of water it lets in. Always a good idea to scrape the paint away from those slits before you launch. I suspect this is all the diver was able to do . . . . he didn't try removing the cover, did he? Anyway, whatever he did 90% solved the problem, didn't it?

I wouldn't want the raw water intake for the engine to not have that cover - Too easy to suck up a plastic bag or some other debris which would stop your water flow completely! If you think the current setup is marginal, you could replace the thru hull and strainer with the next larger size to ensure you have plenty of raw water, especially if you intend to do much running at full throttle

But - I didn't have any overheating problem using the factory thru hull and strainer with my 100 HP Yanmar at full throttle, so if you keep things clean, the existing parts are probably sufficient, IMO

Don

[rnummi]

If I could figure out a way to reduce the size of a pic showing the strainers pre-dunk I'm sure your response would be "hey dufus, you're engine has coronary artery disease... 50% blockage.

[Jay Knoll]

Jeremy

That link doesn't work, got another one or did you perchance print out the article so you could scan it and post it in the doc section?

Thanks

Jay

[rnummi]

Just figured out how to reduce photo size...before I get the collective "doh"
I plead the fifth. I was working on the interior as you all will recall. The spaghetti bowl is the head intake, the small open thru-hull is the generator intake, the scoop is the engine intake, the large open is the head discharge. For those interested as to what finally got my attention it was the comparison to the a/c scoop on the opposite side. I finally was able to compare both side by side. Yes I have an indent from slapping myself upside the head.

[rnummi]

P.S. thanks folks for the comprehensive and wide ranging discussion on this topic. Hopefully it spares other newbs from indenting their head. CaptVic early on: "you have intake blockage"

Simple direct and right on the money....