Vessel Commodore 33
Old Engine Caterpillar 3208 - 435Hp @ 2800rpm
New Engine FPT NEF 450 - 450Hp @ 3000rpm
Gearbox ZF - 1.75:1 Ratio
Vessel Cruise Speed 18 knots @ 2500rpm
Vessel Top Speed 23 knots @ 3000rpm

Re-powering to the FPT (Fiat Powertrain Technology) NEF 450 Marine Engine proves to be an excellent option. Following the failure of a Caterpillar 3208 Marine Engine set at 435Hp @ 2800rpm, assessment proved it was more cost effective to repower to a new FPT NEF 450 450Hp @ 3000rpm Marine Engine rather than rebuilding the 3208 Cat. The Commodore 33 is an excellent performer and is very quick to rise onto the plain. The FPT NEF 450 has offered the vessel an increase in horsepower, whilst also offering a reduction in engine weight. The NEF 450 dry weight: 600kg whereas the Cat 3208 dry weight: 899kg.

When re-powering, our aim is to always achieve a cost effective re-power and replace components as required to ensure that the new engine, when commissioned, meets all manufacturer’s requirements. In this particular case, the 3208 Cat and the NEF 450 share the same flywheel and bell housing size, therefore meaning that the ZF 1.75:1 ratio gearbox could be reused. The SAE 3 housing for Caterpillar are slightly different, and have an additional “ear” on the top right hand side, which hold the starter motor. When we adapt the gearbox to suit the FPT NEF engine, we trim this “ear” off to allow the gearbox housing to connect with ease. There is a minor opening left, however it is never an issue. This is an example of how THT will always work to offer you a cost effective vessel re-power. Because the rear mounts for this drive line are off the gearbox, it meant that only the front mounts needed to be varied to change from Cat to FPT. Even so, the variation is only approximately 50mm.

A new digital control panel was supplied with the NEF, and was custom mounted into the fly bridge control panel.

We supplied the NEF 450 in 24V arrangement so as all existing battery arrangements could be reused as well as reusing the exhaust system and sea water inlet system. The exhaust system had to be increased in diameter in part to ensure the engine back pressure remained low. During the sea trial process, THT re-attended the vessel multiple times without charge to the client to ensure successful sea trial prior to handover. This is all part of the THT commitment to ensuring we support and provide a solution for re-power, not just sell an engine.

The vessel performed exceptionally well with the NEF, achieving cruise speed of approximately 18 knots at 2500rpm and top speed of 23 knots at 3000rpm and one extremely happy owner.