Lorna Adam, our 30-year-old Aquastar Ocean Ranger 33, is fitted with two Nanni 60hp diesel engines which we are very pleased with, writes Stew Proud.

However, the air filters are situated just where engineer’s boots tend to land!

Blaming the engineer is of little use since I do the servicing. At around £67 per replacement diesel engine air filter, I decided to do something about this expensive problem.

What was required was to move the filters to where they’d be less susceptible to damage.

The answer was to use a high-quality car radiator hose and copper pipe to move the filters.

Parts used in the diesel engine air filter modification. Credit: Stew Proud

The parts used were a pair of K&N RU-0210 air filters (I used K&N filters on my motorbike many years ago) bought online, two 42mm straight copper couplers and two 90° silicone radiator coolant hoses.

The photos show the assembly and are self-explanatory.

In the original installation, the black rocker box oil breather pipe was pushed into a hole in the filter.

For the new installation, I drilled a hole in the new red hose and simply pushed the breather pipe into that.

One of the new air filters in situ. Credit: Stew Proud

The filters are washable, so they will last a long time.

Silicone was chosen for the hoses because they are temperature resistant to 180°C.

Red looks smart and has an engineer boot-repellent quality!

With some research, this solution would be possible for many different engine types and installations.

The filters cost approximately £50 each, a pair of 41mm internal diameter Hosemaster silicone radiator coolant hoses were around £36 each, and the 42mm copper joiners are available from plumbing stores for under £2.50 each, so the whole job was completed for under £180.

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