Compression test results advice

[ianainge]

Just had the Tam63p engines on the P360 surveyed and compression tested,one engine has 23 bar on two cylinders compared to 27/28 on the rest and one cylinder is down to 23 on the other engine compared to 27/28 on the rest before i get the doom and gloom diagnosis from the engineers any ideas from the wealth of knowledge on the forum, the sea trial however was ok boat seemed to perform perfectly.reached 31 knots on slight seas dirty bottom full tanks 3 up.

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[BrendanS]

Sounds like just need head off and grind valves in with paste (unless valve seats toughened, in which case specialist needed) Not huge job, nor vastly expensive -

though then again we are talking Marine here - so probably £20,000 thinking about it

<hr width=100% size=1>Utinam logica falsa tuam philisophiam totam suffodiant

 

[ianainge]

its has been suggested that as she performed very well i.e acheiving maximum speed with dirty bottom all that fuel and 1/2 tanks of water, that the turbo waste gates are jamming creating over boost and therefore burning out valves apparently common problem on 63p`s.

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[anchorhandler]

Hello Ian
If you can, take the boat out for another trial and, if possible, check the crankcase breather for any unusual pressure/mist as this will indicate a possible ring pack problem. If your really keen, get hold of an infrared heat gun and measure the temperature of the exhaust manifold (while the engine is loaded up) around the point where the exhaust enters the manifold from the affected cylinder. (I realise with water cooled exh manifolds this can sometimes be dificult). If the valve/seat is damaged or worn you should notice a rise in temperature compared to the other units.
As Brendans said, if its a valve/seat problem then the damage wont be too painfull. Make sure you know though otherwise you could end up paying for an un-neccesary piston overhaul.

<hr width=100% size=1>I'v got 2 ears.2 eyes and 1 mouth....if only i could use them in that proportion!<P ID="edit"><FONT SIZE=-1>Edited by anchorhandler on 12/03/2004 13:58 (server time).</FONT></P>

 

[jfm]

How many hours ian? This engine is genrally regarded as indestructible. Re the low compression, I'm not sure i would even bother to fix it. Doesn't sound too bad. Just run it, sprobly good for annuvver 500hours before heads need work. Of course, you might still getta price haircut.....

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[ianainge]

298 hours, rough quote to do job replace waste gates, sometimes they break when trying to free off, and depending what damage has been done to valves etc,£3000 providing thats what the problem is of course.

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[Nat]

Try checking the simple things first ie valve clearences on suspect cylinders.
Im not familiar with your engine but a tight tappit or partially siezed hydraulic lifter
will also give you this effect.

<hr width=100% size=1>2655 ! You can tell me, I'm a Docter !