What temperature?

[anglosax]

dont believe the gauge 2

I had the same senario as Dave N, the true block temp is read 2-3 minutes after turn off when the block has a chance to equalize the overall temp. We had 140 on the gauge and steam out the back.....

[Mo]

Your thoughts guys.

I just got back from the club. A member on this forum had a problem with his C&C 29, she had markedly reduced water discharge with lots of steam; Temp between 160 and 180. His son is visiting from 1000 miles away and they wanted to go out....so I went right down to see the problem.

1. Checked the water intake...clear.
2. Pulled the cover off the impeller to see if it was intact...it was fine.
3. Removed the thermostat...stuck closed.

Following the re-installation of the impeller and removal of the thermostat it had excellent discharge and temp 120-130 steady. No more steam. He avoided head gasket failure (perhaps more damage) because he looks following each start to ensure she is pumping water. The thermostat likely stuck closed last time out and stayed closed.

Recommendations to this owner. Engine is fine to use now and he will do this when his son goes back in a week or so.

1. Muriatic acid flush. I think she should have had better discharge even with the thermostat stuck.
2. Install by-valve and leave it at 45 degree angle. No thermostat. That works well here in Nova Scotia.
3. Install hotter running plugs which will reduce buildup in the combustion chamber.
4. Something else I noticed....leaned out his carb for him as it was running a bit rich...just noticed sheen in the water...nothing new and he knew he needed to ask me about it.

Not everyone will agree with this approach and I welcome any thoughts or opinions. Please know that I don't charge anyone for helping them out with these engines. Like many of us here on the forum, some people see a problem sorted out in half an hour and it gives them confidence. This gentleman now understands:

1. Notice the problem. The first and most important step.
2. Trouble shoot the problem. We did that.
3. Come up with a plan to correct.
4. Guard against recurrance.

[zellerj]

My Lake Erie water cooled A4 runs at 210 F

I bought my 1982 Catalina 30 in 2000 from a guy that had it 12 years, and he said that it always ran at 210 with no issues. I've owned it for 11 years, checked the thermostat a number of times, acid flushed, put a larger shoe in the water pump, made sure there is plenty of flow out the back , and it still runs at 210. I put in a manual analog gauge and that read 210, so my gauge is working properly.

I have recently purchased an infrared thermometer and the top of the cylinder head reads from 150 to 180 - only very close to the spark plug will I see a reading of 210.

My question is - could the temp gauge be picking up a stream of hot water (sort of like a warm current) from the head so that the gauge does not measure the average block temperature?

Best,
Jim

[ndutton]

Mama mia, that's a spicy meat ball!

I have a few questions Jim,

1. Checked the thermostat? How, stove top test? At what temp did it open?
2. What condition is the inside of the thermostat housing, clean and sharp edges on the inside of the dome or corroded, eroded and rounded over?
3. Raw water or fresh water cooled?
4. Moyer bypass valve or not? If so, closed or not?
5. Have you removed the side cover plate to physically look (and muck out) the water jacket and examine or replace the diverter cap?

[Philip_Warner]

Is over 190 too hot?

I'm new to this forum and I have a FWC system installed by the previous owner several years ago. I got a new temperature sender last season which says about 190-200 and I am concerned about possible overheating. Is there a way to verify the temperature or the coolant flow rate? Touching the outside of the thermostat its pretty hot; more than a brief touch and it would burn my fingers. If I squeeze the coolant tubes they're pretty soft, which suggests maybe there isn't much flow and there could be a blockage, but maybe that's normal. I checked the impeller, and its still got all the vanes and there's lots of seawater coming out with the exhaust, but its no more than lukewarm. Any suggestions on independently gauging the temperature or other remedies would be appreciated.

[Administrator]

Hi, Philip, and welcome!

You'll get lots of responses from folks better informed than I, and lots of questions. Here's one for starters:

When you replaced the temperature sending unit, did you replace the gauge as well?

One thing for you to consider: Normal operating temps (say 140-180) would all be too hot to touch more than just briefly. 180 is scalding hot.

Bill

[JOHN COOKSON]

Every Thing But The Thermostat

RWC engine

Rebuilt the water pump + a new impeller.
Added the Moyer bypass kit.
Acid flush.
Didn't mess with the thermostat since it's operation seemed normal.
Took the temp sending unit out and removed the lime crud that was coating it.
Cross plumbed the manifold so water entered the low end.
Hooked a long hose on the end of the manifold. Started the engine and revved it up. While standing in the cockpit I was able to shoot a stream of water onto the dock.

Once warmed up the engine runs 145-150 for any period of time at any throttle setting with a bump up to the high 150s when slowing down after a period of cruising as when entering the harbor.

I like it.

TRUE GRIT

[ILikeRust]

Quick question: should the temp sensor NOT be wrapped with Teflon tape when screwed into the block? I note that at least one of the sensors I installed recently (now I can't remember which one it was - I'll have to look at the paperwork- it was either a water temp or oil pressure sensor) expressly said not to use Teflon tape, because it needed to get a good ground with the engine.

[Administrator]

Neil will correct me if I blew this, but the give-away is how many leads. If there's only one lead to the sensor (a hot one), then the block is the ground, and Teflon tape is a no-no. If there are two, then the ground is somewhere else, and Teflon tape would be ok.

Bill

[ILikeRust]

Neil will correct me if I blew this, but the give-away is how many leads. If there's only one lead to the sensor (a hot one), then the block is the ground, and Teflon tape is a no-no. If there are two, then the ground is somewhere else, and Teflon tape would be ok.

Bill

That's what I was thinking, too. But then (and I'll have to double-check this again), I think another sensor said to use Teflon tape. And they're all single-wire sensors.

There is just SO MUCH to know. This morning, I spent some time reading Nigel Calder's book - Jiminy Cricket, I feel like I need a four-year degree to learn and understand all that.

[ndutton]

No correction here

I've both heard and read repeatedly about not using teflon tape on single wire self grounding sensors. But, of course, that's not the end of the story.

In spite of instructions to the contrary, I've always used teflon tape in these installations without a single problem. Ever.

[ILikeRust]

Yeah, see, I figure that when you thread the thing in, the points of the thread will cut through the tape and make enough contact to get an electrical connection. The tape helps fill any tiny unevenness or gaps in between.

I know that when I have put Teflon tape on something, threaded it in and then pulled it back out, you can see where the tape has been cut through.

Unless of course you load it up with many wraps of tape, I suppose.

[Brett]

Engine heating up

After launching my catalina 30 for the season I noticed the engine is running hotter than it had last year. I was at about 160 last year and I am at 180 under load and back down to 150 in neutral. I am getting ok flow out the back but also some white smoke. I have not flushed the system in about 3 years so thought about giving that a try. Any other reasons the engine may be getting hot and white smoke? Also...suggestions for removing the impeller clip. Having trouble based on location. Thanks in advance!

[ILikeRust]

Brett, are you raw water cooled, or fresh water cooled?

If you can't get at the impeller, can you get at the two bolts that hold the pump on? Turns a small job into a slightly bigger one, but it's a pretty simple matter to pull the whole pump off - two bolts. Assuming you can get at that bottom bolt (which is why it's nice to have the extendo-bolt).

[ndutton]

I pull the impeller out with the shaft attached. It's much easier to deal with the clip on the bench.