Diesel power for my 36c

[oldd hatt]

I am looking at a used pair of Cummins VT555s to replace the gas motors in my 36c. These motors have 2500 hrs, they seem clean but I know little about diesel technology and would like some input. My budget is limited, that is why I am looking at used motors.

[DaveP]

The old 555's are decent old technology motors. 2500hrs may be at the later part of useful life though, somone with better Cummins experience can better elaborate. The bottom line is unless you are getting these motors for virtually nothing, you may not be happy. Sccording to Powerboat guide the old 36C with 3160 Cats (comparable power) made 15kts at cruise and topped out around 18-19 kts.

A better possibility is look around for some used Yannmars of 370hp vintage or some used 3208 or 3126 Cats. They will be lighter, higher reving, and more modern.

[jim rosenthal]

..are the B series Cummins at 330 hp. They have made a ton of these. You should be able to find them on the rebuild market with no trouble. If you want Cats, try T&S in Crisfield, MD, they have 3116s and 3126s and they rebuild them everyday of the week. The Cummins fit better, though, and are lighter. Note that I have Cats and I like the dealer, but for these boats the Cummins is a better choice.

[oldd hatt]

Thanks guys I think I'll try to locate a pair of 330Bs.

[Mike36c]

In February I pulled a set of 555VT cummins out of my 36 and replaced them with 330b's. The triple nicks have a few problems one of which is the stainless exhaust elbows that can allow raw water into the cylinders and are expensive to replace/repair. Another issue is the room to work on them, very tight. My engines were old and tired, they smoked a LOT , all the time, but produced rated RPM and were extremely tough and hard to kill. You will shovel out a lot of money just converting to diesel (shaft work, fuel systems, engine mounts, props, painting, etc.) so go with something that you will enjoy. The triple nicks will add little or no value to your boat, even if they are rebuilt and pretty. They are slow, heavy, Smokey old technology.
I love the 330's in this boat (a series 1 36c) and although she is no rocketship I cruise fully Bahama loaded at 23kts without working the engines too hard and they are clean, smooth and efficient. Parts are readily available/reasonably priced and mechanics easy to find. Oh, and 2000lbs lighter. Hope this helps. Mike

[oldd hatt]

Mike' thanks for the info. What drives and ratios did you use with the 330's?

[Mike36c]

The latest trend seems to be the ZF 1.75:1. Tom Slane indicated he has had good results going this route. I initially was going to go this way but had a tough decision to make, ZF or Twin Disc. Being a die hard TD guy I went with the 5055a but it wasn't available in 1.75:1 so I went with 1.5:1. It allowed me to stay with 1.5" shafts as the $$ are limited. I'm delighted with the results, fearing vibration the running gear is surprisingly smooth but the 1.75:1 should be even nicer maybe gaining a knot or two in cruise. Hope this helps, Mike