What would this do?

[Bry21317]

I am wondering on the way that the air vents into my engine. The only vent is located at the top backside of my cowling, on an 88 Force 125 HP engine. I am wondering if I made a cut out in the front side, sorta like Ram air on a motorcycle, what would this do? There is no air filters on this engine either, I don't much like running this without them, but it never had them.<br /><br />Any input would be great. I just figure if it is getting more air, it may help some, never know.<br /><br />Thanks,<br />Bryan Cox<br />MTU

 

[jobassing]

Re: What would this do?

i might be wrong but boats don't need air filters thay dont run in the dust

 

[kenimpzoom]

Re: What would this do?

I always was concerned about no air filter too, but remember, they run on the water, and there is usually no dust/dirt out on the water.<br /><br />As far as the ram air, would be possible, but probably safety reasons why you shouldn't. I let someone else answere this, as I have thought about it also. Maybe you dont want a backfire to come out towards the passengers.<br /><br />Ken

 

[Brew]

Re: What would this do?

I'm certainly no expert on this, but if you added a lot more air to the "system", wouldn't you mess up the air/gas ratio that the carbs take care of? I imagine that if you forced that extra air through the carbs, you'd stall the engine for lack of gas once you got the boat speed got high enough.<br /><br />Just a thought before you go putting holes in things.<br /><br />Good luck!

 

[Dhadley]

Re: What would this do?

I have no idea about a Force but on a crossflow E/J (OMC) it may help slightly. On a looper the "ram air" effect will screw it up totally!<br /><br />Good luck!

 

[EatMoreFish]

Re: What would this do?

Bet you would not notice a thing and if you had a fire the flames would come out of the front of the cover and not the back giving you less time to react before it was to late.<br /><br />I don't see how just cutting a hole would force more air into the carbs. you would have to duct it to them somehow. Then the CG may require a flame arrestor of some type

 

[FlyBoyMark]

Re: What would this do?

"RAM" air will screw up the mixture, BUT, allowing the engine more "free air" will improve performance without mixture problems. Ex: Remove intake muffler(if equipped) and cowling muffler (if equipped) net gain should be 100 rpm on engines to 40 HP or more for larger engines.<br /><br />This will of course increase the reed valve noise too. I would not do this to a new engine because the engine is now making more than its rated HP and could effect warranty.....

 

[wilde1j]

Re: What would this do?

One more thought on the RAM air thing. You need to make sure a slug of water cannot enter the induction throats or bye bye motor. Small racing outboards run without cowling typically have a big plate mounted in front of the carbs to prevent water ingestion.