Caterpillar C18 ACERT

Assassin

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Has anyone any experiences of these engines, their problems/issues as the new boat has them fitted, so would like to be aware of any potential problems.

Rated at 1150 HP.
 
I would use search engine for this, and wait for latestarter off this forum he will be able to add some correct info on your engines im sure.
 
My direct experience is only with the 873 Hp single turbo rating.

Single turbo C18's in MOD Police vessels have proven to be rock solid, some of the older ones have racked up close to 11,000 hours without a single mission disabling failure.

I do not recognise an 1150 Hp rating, probably me being out of touch. Highest rating I have data on is the 1015 Metric Hp rating with sequential turbochargers.

Some of the 1015's operating in North Sea ambulance Rib’s for a few years now. Ray Johnson head of Scania marine sales sold them when he worked for Finnings, be careful of the spec sheet envelope data. CAT data sheets are normally 100%; however the single turbo dimensions and weights became transposed to the twin turbo sheet causing all manner of grief during the build, worth checking.

C18 has high piston speed, many predicted that this would be the engines fuse; it has proven the cynics wrong.

There have been a few reported cases of the turbo crossover pipe and turbo failing on the twin turbo engines apparently due to insufficient component tolerance to allow for growth when engine gets mad hot.

Only kid on the block in the 800-1000 Hp power node until new Scania V8 arrives.

One downside is that motor is NOISY! make plenty of provision for sound proofing if new build.
 
Feels a pretty powerful option on a 31tonne (light) boat, so should be fast

Regarding Caterpillar back up, where are you going to be berthing her Assassin?
 
Many thanks for that, i had heard about the turbo pipe and apparently it has been modified and is apparantly manufactured to higher standards for this higher power variant. This probably explains why i can find little negative about the engines anywhere, and i have looked, the Caterpillar marine site gives little information about this engine, the engine manual gives a lot more.

It is a noisy engine, the usual high speed diesel combustion clatter is evident, but the boat is well soundproofed so noise is not really an issue, i don't think the thinwall technologies now uses contribute to noise suppression anyway. This is a foible on all newer high speed diesels, not just Cats.

They are a quick engine option, but i have found that winding the speed back a little gives a excellent compromise between reasonable pace and consumption, and it accelerates well from all speeds.
 
i have found that winding the speed back a little gives a excellent compromise between reasonable pace and consumption, and it accelerates well from all speeds.

Have you already taken delivery Assassin? (In which case, congratulations!) Would love to see pics of her if you can post. What part of the world?
 
It is a noisy engine, the usual high speed diesel combustion clatter is evident, but the boat is well soundproofed so noise is not really an issue, i don't think the thinwall technologies now uses contribute to noise suppression anyway. This is a foible on all newer high speed diesels, not just Cats.

Certainly do not agree that it is a modern engine foible. European engines do a far better job.

C18 is just 3406E with a dose of attitude. Bore went from 5,4 to 5.7 and new crank increased stroke from 6.5 to 7.2 hence the high piston speed. The big issue was that 3406 was a low cam in block motor converted to overhead cam, front cam gear drive is a little clunky and a BIG noise producer. My old chief engineer was at one time senior draughtsman at Henry Medows; he rightly asserted that the only place for the timing gears is on the back of an engine.

CAT's other problem is noise reduction by using injection rate shaping, CAT made exit of the US truck market due to inability to get their feet on the pedals for EPA 2010 emissions. CAT is running a C15 with common rail in Navistar test labs with some good results. ACERT was an expedition up a blind alleyway.
 
Certainly do not agree that it is a modern engine foible. European engines do a far better job.

C18 is just 3406E with a dose of attitude. Bore went from 5,4 to 5.7 and new crank increased stroke from 6.5 to 7.2 hence the high piston speed. The big issue was that 3406 was a low cam in block motor converted to overhead cam, front cam gear drive is a little clunky and a BIG noise producer. My old chief engineer was at one time senior draughtsman at Henry Medows; he rightly asserted that the only place for the timing gears is on the back of an engine.

CAT's other problem is noise reduction by using injection rate shaping, CAT made exit of the US truck market due to inability to get their feet on the pedals for EPA 2010 emissions. CAT is running a C15 with common rail in Navistar test labs with some good results. ACERT was an expedition up a blind alleyway.

Paul I like your theory on noise and stroking/bore ie more bucks for the same casting/ not much development cost.

That reminds me of the TAMD 75p motors, compared to the D6 with yes as you said it the timing gear at the right end of the motor!.
 
I think you misinterpreted my original post, most modern diesels use one form or another of combustion shaping and Cat have done very little different using sequencial burst injection and air monitoring. This does give better atomisation and pre combustion characteristicsto increase fuel burn speeds, and combined with combustion shaping geometry, but most other engine manufacturers do the same which increases diesel combustion clatter.

Many other manufacturers incorporate harmonic damping methodologies into their casting designs, Cat do but are nowhere as good as other manufacturers at suppressing this. Basically a lot more combustion noise is transmitted through the engine in Cats; other manufacturers develop their engines to suppress this NVH in their engines for lower in service noise emissions.

Timing gears do contribute to any noise emission, again many other manufacturers suppress this better, and is a fair point, and one which can exacerbate injection pulsing systems on high speed diesels.
 
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