im thinking about making some custom aluminum side vents to replace the plastic ones but i have some concerns about enough air flow to the motors. the plastic vents direct air flow into the engine compartment. the ones im thinking of making wont do that. could this be a problem or am i worrying about it to much?

another view

why are you going to make them they have lots of cool looking chrome ones not sure about aluminum ones.

plastic vent.

The vent you would like will tend to create negative pressure in the engine bay. The plastic vent, as long as its facing into the wind, will attempt to create a positive pressure in the engine room. Your carb needs a lot of air and the higher the pressure it can draw from the better the engine will run. This is why a blower works.

That is all in theory. In practice, I think you can use the one you want with no ill affects. My panthers grills are not louvered, although I wish they were.

BT

thanks for the reply BT.
ive read that the motors in my boat , 502 efi's , have vapor lock problems when hot although ive never experienced myself. thats why im concerned about airflow.

Depends on a lot of intangible stuff, but some boats at speed run negative pressure down the sides near the rear. Those boats receive no benefit whatsoever from the vents that have "scoops" on them.

Bottom line is just make sure you have a lot of AREA of vents and the motor will do fine.

You can get a manometer and have somebody take readings at different places you plan to install more vents to see if those areas run positive or negative pressure. Positive pressure will put air into the vent. Negative pressure will pull air out of the vent.

Optimum situation is to have both, with enough coming in to feed the motor PLUS an additional volume to change out the air in there thru the outgoing vents.

Lots of boats out there running small vents for big power. Not what you want.

loto, I switched from the same vents you have pictured to the EMI vents and did not see any difference.

mine has one side with the scoops facing forward the other side they face backwards i guess this is to creat flow at crusing speeds. by forcing it in onside and creating a vacum (sp) on the other side.

Griff , did you enlarge the cutouts in your boat when you went to the EMI's?