[ohcaptainron]

Looking at a boat that has this series engine, start well, no smoke 2500hrs.
I do not have any experience with these engines, my question's are; reliability? parts availability and costs? any general operating comments.

Thx
Ron

[K1W1]

Hi,

I have had a lot of exposure to these things in trucks and off highway vehicles.

It is probably the worst thing Cummins ever produced, te rest of the range is excellent but somehow the 555 missed the mark in a big way.

I would not touch them with a barge pole.

[Loren Schweizer]

Ah, yes, the old 'Triple Nickel'...these saw service in quite a few Bertram 35 & 38s in the late '70s. I don't recall too many problems (whenever the sales guys hear about service issues, then there is a Problem)...they had a Company Boat, a 35, which mostly was used by George Good, Bertram's President at that time.
A young sales guy had the onerous task of shuttling that boat down (or back from) to Ocean Reef or over to Cat Cay...lots of hours on those motors with only an odd quirk late in the game: the boat seemed to have lost speed over time. Bottom was clean, there was not a lot of extra stuff onboard, a mystery... Cummins' answer was to just turn up the PT (pressure-time) or fuel pump to get the speed back.
Bertram's engineering department was not impressed.

Then, there was a Jim Smith ( a sportfisher) with a pair of triple nickels called "Speed Merchant" whose owner hooked up a nitrous bottle to the motors to get an outrageous top end speed (no, I don't remember how fast) for that era and the engines didn't go Kaboom.

Cummins were popular, but they had a reputation for service guys showing up greasy & dirty on sqeaky-clean boats...

[SeaEric]

I owned a pair of "triple nickels" in a 43 Egg Harbor (wood) 20 years ago. The parts were scary expensive back then. That cannot have improved.