I'm sure this has been discussed before but my search did not pull anything up.
I intend to install a walker airsep on my Universal 5444(Kabota) V-1902 engine
in an O'day 39. I'm also installing new Sound down soundproofing and intend to seal up the engine
room as much as possible.
The Walker Airsep I intend to install is designed for gen sets and small sailboat auxiliaries up to 350 CFM. Walker Engineering - Product Detail
I googled how to calculate cfm for engines and got many formulations and calculations all offering results often magnitudes apart. Some use fuel
consumtion and the air fuel
ratio others go with volumetric efficiency yet others seem to take into account everything including the rotational spin of the earth.
I found a slick chart that looks impressive and if the author spent half as much time in with the formula as he did with the graphics it should be most accurate. The answer I got was 90 CFM for the 44 HP engine. Seems a bit low.
Engine room ventilation , Based on this result and some overkill I intend to use 4" vent hose with two intakes at 4" and one powered exhaust
at 4". 240 CFM fan.
No. of Cylinders 4
Bore X Stroke 3.3X3.25
Cu. In. 115
Rotational speed of the earth 1 rpd
Don't know fuel consumption/hr.
What do you think am I anywhere close?