Caterpillar C8.7 temperature query

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ThunderChild II
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Caterpillar C8.7 temperature query

Post by ThunderChild II »

We are running four "identical" Caterpillar C8.7 engines in a 23m endurance power boat - see www.54knots.com. The engines feed ZF two-speed gearboxes, and their output is via four France Helice surface drives.

For some reason, our port outer engine runs warmer than the other three - the attached photo shows the issue at 43 Knots. We have cleaned all the raw water systems and renewed all the raw water pipework, seacocks, and strainers are clear. The vessel is highly maintained. I have been advised that engines run differently; the thermostat has only been changed on this engine. The engines are on the Caterpillar extended warranty program.

The temperature rise is progressive and stops at 94c, and ironically the port outer engine warms up more slowly than the other three. In a recent passage from Sines in Portugal to Gibraltar, we dropped into a few troughs at around 36 - 38 knots, and the temperature appeared to drop suddenly to the same range as the other three engines before gradually rising again. Any thoughts or suggestions would be welcome, as we are a few weeks away from doing around 4000nm on some UIM endurance events in the Mediterranean.

Thanks for any help, and you can see us if you are in or around Monaco from 6/7th June,

Nick
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port outer.jpg
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Merlyn
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Re: Caterpillar C8.7 temperature query

Post by Merlyn »

Thats a fast old canoe you have there, slammer jobby indeed.
When I have encountered similar problems I have used IR temp detectors, being a ray shiner you can isolate temp. in temp. out from seasuction to pumping it back over the side.
Pipework, charge air coolers , all heat exchangers, pumps, thermostats raw water/fresh water pumps etc. etc. can be measured accurately thought the system plus you have the advantage of drawing comparisons with the other three at similar testing zones.
Still very difficult to pinpoint if its an intermittent fault as allways.
Rayguns have come right down in price and are cheap as chips.
Not to be done in a drop of roughers mind especially when leaping from wave to wave in a seaway.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.
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Merlyn
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Re: Caterpillar C8.7 temperature query

Post by Merlyn »

Got any scoops fitted to the hull outside of the sea suctions?
Damaged/missing/restricted flow/foreign bodies obstructions etc?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.
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Merlyn
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Re: Caterpillar C8.7 temperature query

Post by Merlyn »

Got any scoops fitted to the hull outside of the sea suctions?
Bent/damaged/foreign bodies etc restricting flow rates etc?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.
ThunderChild II
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Re: Caterpillar C8.7 temperature query

Post by ThunderChild II »

Yes we have scoops, all brand new and identical on both hulls.
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Re: Caterpillar C8.7 temperature query

Post by popeye62 »

Hi Nick. I have never been that fast over water. Can you describe the raw cooling system? Does the port inner share a cooling system (raw water) with the port outer (The PI is at 91 degrees)? How is the JCW cooled, a heat exchanger? Was the thermostat changed because of this issue and is it the correct thermostat? If the PO is coming up to temperature more slowly it suggests that the thermostat is open at low temperature (Is it a regular wax-type element?). Is the engine developing the same power as before? Are there any other symptoms? My experience of planing hulls is very limited but when you hit the rough weather and the temp dropped could that be because the intake was deeper in the water because you had come off plane? Could there be air passing through the raw water pipework/scoops etc? Is the exhaust from PO any hotter? Can it breathe as well as the others? Do you get any alarms?
John
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Re: Caterpillar C8.7 temperature query

Post by The Dieselduck »

Its kinda strange that both port engines are showing higher temps, not critical temps, but higher. Suggest to me a common cause - you've got harnesson drives which are pretty easy to check, but some prop fouling or damage? How is your fuel consumption or turbo temps?
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Re: Caterpillar C8.7 temperature query

Post by Atlantic »

It seems like the load is higher on port side. It shows 100% but is that correct? How are the exhaust gas temps and turbo pressure? How are the turbo filters and air supply? Also when was temp sensor calibrated last?
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