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Old 03-08-2011, 09:43 AM   #5
jleonard
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RE: ford lehman 2728T

Quote:
knotheadcharters wrote:




I am looking at a boat with ford lehman* 2728T. I cannot find specs for this motor. I assume the T means turbo charged but what about rated horsepower? They have 1500 hours on them in a 1987 boat. Just trying to figure out more. Also can you just remove the turbos or are there other things that need to be done in order to convert them? Specs say boat will run from 16-20kts semi-displacement?? I find this hard to believe. *I plan on running 8-10kts and if so will that coke up the turbos or can they be run that slowlywithout problems?

A boater at my marina has a 42 Marine Trader aft cabin circa 1987 (I forget the exact nomenclature) with twin Ford Lehman turbocharged 225 hp enignes. He CAN run up at 18 knots but normally he doesn't.
I am not positive what model designation the engines are.

And I agree there is no reason to remove the turbochargers.

They won't "coke up" at low rpm...that is not what coking is. "Coking" comes from too high a temperature for the oil. It can happen to a turbochrger when you rev up the engine and get the turbo really hot, then shut it down. The turbo still sppins at high rpom and it "burns" the oil, breaks it down and it cakes on the shaft and bearing surfaces. That is "coking".
It can also happen after a long hard use and shutting down before the turbo cools off. ie in a vehicle that goes hard up a long hill, pulls into a parking lot or driveway, and shuts the engine off without idling for a few minutes to allow cooling. Usually a boat has to do some idling to dock so generally this is scenario doesn't apply to boats.

You are more apt to have clogging issues with a raw water aftercooler at low rpm. The cold water will condense the moisture in the air and it mixes with the PCV fumes and clogs things up. Plus really cold air may make the cylinder temps very low and allow problems there.
These issues are resolved by running up for a few minutes near the end of a cruising day to heat the enigne up good and burn everything off.

If you are still insistant about removing the turbocharged capabilities, then you'l have to reclibrate the injection pump and "maybe" change out injectors along with replumbing the air intake system.
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