Italian Tune Up

[ss2016]

The expression 'Italian Tune Up' was new to me until recently, but now I have noticed it several times. I follow the logic of occasional WOT operation to clear the carbon but do have one concern. Late in the season most of our boats have a degree of fouling which means that the boat can not reach its full rated revs. In my case, a D6-400, WOT results in a drop of the revs from 3450 to about 3200. This leads me to question if it can ended up over boosted? Perhaps the EVC guards against this?

 

[Portofino]

It’s the load really you need to see near 100 % for an “ Italian tune up “ .Fouling will mean you reach this at lower rpms .

Better still the EGT s and reference the manual .Try not to exceed the suggested max .Otherwise you are going from carbon burning off the tips ( desirable sure ) to the tips distorting and exhaust valve / seat distortion .

Water in fuel is a tip destroyer at excessive EGTs , it breaks down into hydrogen and melts them = fuel hosing = holed alloy piston = new engine or rebuild if possible. Presume it’s got WIF alarms ? If not you might like to beef that side up fit racors with clear bowls and drain taps .

If you can’t see these two you are essentially flying blind .Revs are a poor sub. But if it’s the only delta you are measuring- Don’t push it if fouled .

Shouldn’t have any fouling by now ( Sept ) imho if the correct AF s been applied for the locality.Mine hasn’t inc the stern gear . It’s the props hygiene which have the biggest effect on your engine loading , followed ( with smaller planing boats ) the weight , crap accumulation.

Hull fouling = just runs slower knots at a given rpm .

Can you keep the props clean ? Easily ?

I don’t think they over boost as you say the electrotwackery and dump valve if fitted takes care . Talking turbo boost pressure ?

Manufacturers of the engines expect clean stern gear and reasonably clean hulls .

If you can see the fuel delta and know it’s max you should roughly know / work out the load .
You May find this informative?
https://www.outerreefyachts.com/docs/How-Long-Will-My-Engine-Last-PassageMaker.pdf

 

[ChromeDome]

Italian tune-up has been used a term for different sorts of magic - like pouring carbonized water down the the intake at high rpm to "remove " carbon in cylinders.

Must say I'm not a fan - especially when considering modern diesels with all their EGR's, sensors, filters, switches and what not.

No matter how you tweak the facts, burning of oil will create soot. EGR's (even when two are fitted), DPF's, catalysts and what not eventually will fail/block.

By experience, the use of engines should meet what they're designed for: WORK! That'll, provided they receive regular service, keep them happy for longer!
Potting around for ages won't help - as a highly regarded forum member said once: "Tacho in the red once a week is what counts!"

If propped right you won't reach the red area on that tacho, but you get the idea.

FYI:
Mine (thank God) are neither electronic nor EGR nor DPF. I regularly go WOT on both (24 knots in my case), then, in turn, pull them back to idle for some 10-15 minutes, allowing the one at work to really prove it is performing as it should (keeping the boat on the plane!).

FYI I recently sent oil samples off for analysis: Both clear as a whistle.
The Senior Analyst actually complimented them for the nice results.

And they are 19 years old, 3 liter, 4 cyl., turbo & intercooler, fresh water cooled engines..

 

[ss2016]

Portofino, thank you for your comments. Having had a bit of a read since I wrote that I don't think it likely that the engine will go out of range on either EGT or Boost since the engine is well guarded by the ECU. Similarly, a water in the fuel sensor and indeed a Racor. My interest is more academic than worry!
Irritatingly VP are a bit coy about giving out info though I do think max boost is 26psi, I only ever see 22, but I have seen no reference to max EGT though I think it is around 575C. The ECU knows but I have not found a way to read the parameter.
I am slightly puzzled by your comment WRT fouling. My boat went in the water 8 months ago and by now there will be some slime on the Hempel Hard Racing and the props will be stained. (Cornwall by the way.) Quite a bit of growth on the leg but mostly only behind the transom. Weight I keep an eye on (I used to fly) but there is undoubtedly more than when it had its test run at the factory. (Tools, 2 gas bottles, extra lines/fenders, dinghy. o/b etc..) I don't worry about the fouling this late in the season. Our longer trips, Brittany, Scilly are done before the ankle biters are off. Now it's just local picnics etc.
I am with you WRT care of the engine. Strict adherence to the service requirements. Most operation is between 28/2900 since this is the most economic lpm, or lollygagging but then a short burst before we get home if possible.

 

[ss2016]

Chrome Dome, thanks for your input. Portofino, Interesting article you linked. Thanks.