ADDING COWL VENTS

[dmarkvid2]

I just replaced the engine in my boat with a Mercruiser 5.7 V8 Alpha1 Gen1. The original engine was a V6. I don't know the size. I am thinking now that the engine is bigger, it will be giving off more heat in the same amount if space that the V6 was in. To help remove the heat in the engine compartment, I wanted to add more ventilation. There are two side vents 17"x 2 1/2" on the outsides of the boat at the stern. I want to buy two cowl vents, and place them on top of the transom, somewhere above the engine with the openings of the cowl vents facing the back to draw the heat out as I am underway. Would this be a good idea? Would this help?

[PuddleJumper]

I would suggest one facing back and the other facing fwd. Creates pos pressure at one vent and neg pressure at the othe for exchanging air in compartment

[dmarkvid2]

Thanks Deej, Good idea, and I think you're right. When I took a closer look at the two vents on eirther side, I noticed the fins on one vent were facing forward, and the other fins were facing aft. One more question for ya. The cowl vents have a 3" Dia. flange that fits through the hole in the fiberglass. Do you think these flanges are there to clamp a vent hose to them, like blower hose? If so, how long should I make the hose? Or is it better just to leave them the way they are? About 1" long.

[Always Broke]

I think you might be worrying for nothing 160 degrees is 160 degrees no matter if itÂ’s coming off a V6 or a V8 if your running hotter then your service manual recommends then thereÂ’s a problem. If your worried about heat in the passenger area of the boat you might want to consider insulation on the engine hatch. Then again the extra vents wonÂ’t hurt anything so if ya want to go through the trouble go for it.