Ford Lehman SP275 - general comments?

Panama Dave said:

We just bought a boat with 275s and discovered shortly after purchase it had leaky aftercooler cores. Bomac marine could get them for us. They were $1800.00 each and took about 3 weeks to get from England. We were told they had just become available again after 4 years of unavailability. We just got back to the boat after some yard work so it is not tested yet. Good luck. We are headed from Tampa Bay to the keys, then home to Texas.

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Give us a holler when you get home and let us raise a glass!!!!

Baker said:

Give us a holler when you get home and let us raise a glass!!!!

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Where do you keep your boat? We will be in Waterford Harbor.

Panama Dave said:

Where do you keep your boat? We will be in Waterford Harbor.

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South Shore Harbor for us!!!

I have owned a 1989 Marine Trader with Sp275's for 2 years and spending time catching up on maintenance items, last year refurbed Heat Exchangers, and this spring just completed both intercoolers and one rebuilt turbo. Still experiencing 210-220 deg f on stbd guages, IR Heat gun reads no more than 170 on any part of engine,about 5 deg hotter than port. Can anyone tell me where to locate temp sender unit?

Without a doubt you likely need a new sending unit. Contact Brian at American Diesel.

I can’t speak on the 275’s but I just bought a 42’ CHB Sundeck with the SP160’s which are turbo’d without the intercooler. After talking with American Diesel I would also do anything possible to bypass the intercoolers. Even with that extra HP I wouldn’t imagine the extra knot of two would be worth the amount of extra fuel you would burn. PM me if you have any questions on the CHB’s and their gremlins. I’ve dedicated my last 4 months to trying to figure it all out and fix the big stuff (fuel tanks, leaking windows, soft decks). Cheers

Justin

I bypassed the intercoolers on my SP225s this winter. It is simple. But I think that the 275 is a different story. I am not sure how involved it is or isn’t. Mine took about a half hour per engine to bypass. Some 1 1/8” hose and some clamps.

Before bypassing after-cooler install exhaust pyrometer if possible first.
Then run slowly up to full governed rpm at full load noting exhaust temp every 100 rpm. This will give you baseline for maximum exhaust temp at full power and load with functioning after-cooler.
After bypassing after-cooler, keep pyrometer temperature 15% lower.
Did this to 375 hp 3208 after bypassing after-cooler.
Will re-pitch props at haul out as cant exceed 2400 rpm without exhaust temperature exceeding safe formula.