Vent for Motor Cover?

The older style motor boxes had vents, so I dont think theres much harm in adding them.

Heat really shouldnt cause any engine troubles though- these motors only run at 160 degrees. I believe heat soak issues are usually carb related.

rex marine and livorsi sell a vent that goes under the handle of the motor box that you cant even see, thats what im going to put on mine for better air flow! Look

Eric, Oh Man of Great Wisdom,one more use for a tool we all have in our shop.
Will not tell you of the weather here,but can you spell shorts and a tee shirt.................80s all week
               boat dr

Add timing to the list of possible problems Chris lists above that can cause some overheating problems...

I never see water temperatures over 170 degrees. However, it sure does get hot under the cover where the distributor is located. There is no telling what the air temperature is inside the top of that box. I see alot of ignition related posts. I would think that our wiring, coils, ignitions, and whatever would last longer if this heat had a way to escape. My ignition module is shot and I think it is from the heat. I'd rather not cut a hole, but if it makes my boat more reliable, then I'll do it. Has anyone driven without the motor cover?

I would try to run your blower all the time . That will be bringing in fresh air from the bow and sending it out the back . I really wouldnt think that hot air under the hood would creat a problem . Think of a black car out in the sun in 110 degree heat with . I wouldnt guess there would be a constant problem with these , otherwords there would be no black cars in Arizona. My .02

Pat

That sounds good and logical to me. Along those ilnes, let me share this air flow phenomenon: When we bought our '63 Classic, the original owner had added a neat and "somewhat original" looking fiberglass hood scoop, which resembles something from a '55-'57 Tbird. The scoop is/was an actual Ford Motor Company piece based off the Fomoco emblem molded underneath, which lends no credibility or plausibility, just observation. Regardless, I thought it would provide additional air to the big 390 engine and when polled, all my buddies said leave it when we installed new vinyl last year. But I'm here to tell you now that it doesn't suck more air, as was witnessed by the severe case of blow-by this engine had. The faster you went, the more and more smoke came barreling out that scoop right over your shoulder. These older boats came only with a forward and aft facing scoop on either side of the top deck just aft of the helm with a pipe that led down under the floor. Nothing on the front or rear decks. PO had added an elec blower to one side.

To more address MMs plan of adding some type of intake vent, (I didn't see actual pict yet) you may have to duct it directly to the carb if that's where you want the air to go, as opposed to it ending up as an exhaust like mine is. When my engine goes back in, I may investigate some means of concocting a gasket under the scoop/engine box, that only lets the flame arrestor pop thru. I'm not anticipating any more smoke, but the engine noise right there in your left ear, aided by solid lifters, was also a little annoying.