Sealine S24 (Fat Girl) got to 28 Knots but a little warm I feel

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Bigplumbs

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Having owned my Sealine S24 (Kept on the Norfolk Broads) since about March I have not yet had a chance to see what she can do. She has a Volvo Penta KAD 32 in her.

She is quite loaded up as a lot of broads boats seem to be and I had 80 % full fuel and water and about 30 % full waste tank. There was only me and her indoors on board.

So off we went to Breydon water (No Speed limit) and gave her a blast. I am pleased to say she got on the plane ok and did 28 knots. Because of other cruisers approaching and the general thinness of Breydon I only did this speed for about 45 seconds. What I did notice however is that the temp gauge rose quite quickly and at WOT it got to about 95 degrees C which I felt was a little hot. By this time I had throttled to displacement speed so never had a chance to back off to say 22 Knots to see if the temp stabilised and ran ok. When I did drop to displacement the temp dropped to about 78/80 degrees which according to the manual is fine (Range is 75 - 90).

I have read an old post where Volvo Paul says that a KAD 32 can get to 96 so was not overly worried but need to do a better test.

I was wondering what others with KAD 32's see on the temp gauge when they are getting to Max speed.

I Also wonder how good these older gauges (20 years old) are

Thanks in advance

Dennis
 
(considering replying, but unsure if suggesting expensive fix will result in me rotating slowly over hot coals)
 
FlowerPower said:
(considering replying, but unsure if suggesting expensive fix will result in me rotating slowly over hot coals)
Click to expand...

I don't know that I need a fix at all yet as I am starting to feel (from replies in the sealine forum) that what I saw was as many others have. I think before one goes for any fix that is expensive it is better to try the less expensive fix first.

Probably starting with replacing the intercooler is not the first thing to do.

Also as I have tried to demonstrate on here several times 'Expensive' is relative to how much you have in your sporran.

This older thread was useful and sort of demonstrates not to go for the expensive first

http://www.ybw.com/forums/archive/index.php/t-404115.html

Do you feel at all as though the rotation has started yet and lets face it you havn't even offered an answer yet :)

Dennis
 
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Starting with the cheap fixes, first then :) ...
I would check the water intake on the outdrive, check that the intake hose is secure, undamaged.
Check Sea Water Impeller.
Remove and examine the exhaust elbow - should not have bits of broken impeller or massive chunks of rust blocking the outlets.
 
Get an IR gun and double check your gauges against it. I found dirty terminals causing a bit of resistance gave me a 10C degree higher reading on starboard engine and 5C degree higher reading on port. If I switched on dash instrument lighting this increased the readings by another 5 degrees on both. That was 1/3 the problem on mine. The other 2/3rds was barnacles in the drive raw water intake slots blocking flow. This caused one of the raw water pipes to pinch under heavy load and I believe stripped the centre boss of the impeller (Thanks to Kashurst for identifying) This would only happen under high revs though. The impeller had enough friction over it's centre boss to work perfectly at lower revs. Looking at the impeller you'd never guess there was an issue, nor by testing with hand. But replacing it was the third and final piece that resolved my problem. YMMV
 
BruceK said:
Get an IR gun and double check your gauges against it. I found dirty terminals causing a bit of resistance gave me a 10C degree higher reading on starboard engine and 5C degree higher reading on port. If I switched on dash instrument lighting this increased the readings by another 5 degrees on both.
Click to expand...

That's very interesting! Years ago I had a boat that increased the temperature gauge reading by about 5C degrees if I turned the dash lights on - never understood why until now! (I just ran with them off - cheapest fix of all! :D )
 
Dennis
when I seatrialed my Seawings with the AD31P - Same engine as yours I believe without the supercharger. She hit 93.3 C, 200F at WOT before we backed off, and my engineer was not happy.
The owner had the water intakes checked and replaced the impeller. She now will not go above 90 C at WOT

Chris
 
Found the temp specs in the book that came with my KAD32 says 81/94 degrees C so perhaps my temps were ok. See attached

Perhaps the issue was I was comparing them with my Mercruiser 3 ltr which seem much lower but raw water and no pressurisation of course
Temp_Specs.jpg
 
In my limited experience raw water cooled engines do run cooler, at least, if the block is relatively corrosion free.
 
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