Engine compartment access hatches and fire.

[Ian_Rob]

I want to install an inspection panel in the starboard side of my engine compartment to give me proper access to the oil filter and drain points. There are hatches on the other sides but none on the starboard side making removal of the oil filter very difficult. A 150-200mm circular plastic inspection panel would be the right size and easy to fit but do I need to worry about fire rating? All the other access panels are wood and though they wouldn't achieve a long period of fire resistance, their performance would better than any melting plastic hatch.

 

[macd]

A plastic job wouldn't do much for sound insulation, either.
Might you treat it as a 'cosmetic' door and add something less elegant but more sound- and fire-retardant behind it? Presumably it would only be used once or twice a year, so could simply be screwed in place.

 

[Ian_Rob]

I was thinking that the core of sound-deadening foam removed could be stuck to the back of the access panel but that would still make it weak from a fire POV.

 

[charles_reed]

My boat has had just such a plastic access hatch, fitted new 25 years ago, to access the oil filter on the 2GM. It now serves adequately to access the filter on the 3YM.
It has not resulted in any excessive noise, though all the faces of the box do need good lead/acoustic sound insulation.
As it's not my habit to barbeque in the engine compartment, so I've never given a thought to fireproofing. (I'd guess diesel soaked closed-cell foam would burn well).
Of the 6 fires of which I have knowledge, aboard a boat, I've not known of one started by the engine - 2 by electric shorts, 1 by a runaway battery conflagration, 1 by an LPG leak and one by using spray adhesive near a gas-cooled fridge - the last was probably a runaway chip-pan. In 5 the boat had to be abandoned and written off.