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Ram Air / Air intake
- Thread starter jeffswav
- Start date
26 Spyder
New member
Project is looking awesome! I plan a similar setup on the Squadron..
Here are a few pics of some testing on the Cobalt I just completed.
To address the functionality of the "Ram Air", Merc used it on its new 1300/1350 engine with a 50 HP gain! Apparently there is some truth to the theory...
From Mercs website; http://mercuryracing.com/1300/
"Air Intake
The horsepower these engines boast is directly related to the way they breathe. The air induction. As is typical for most sterndrives, the 1300 breathes ambient air from the engine room. The 1350, on the other hand, breathes cooler outside air through a direct air induction system. It’s that cooler air that gives it the extra boost of 50 hp. The air induction system does require computer aided design (CAD) integration with your boat."
As for the water ingestion a little mist, rain or spray would prolly never make it through all of the ducting and in to the TB. Especially at the speeds you would be running when it is raining. Just have a low spot in the duct and a small drain hole, 1/4" or so will be plenty. Anyway, I have ran engines with water and water/methanol injection so again a little spray will not hurt a thing.
Now, if you stuff the boat and the wall of water hits the scoop that would be a different story....
And it seems you have covered the engine compartment ventilation needs as well so again, awesome project!:USA:
Here are a few pics of some testing on the Cobalt I just completed.
To address the functionality of the "Ram Air", Merc used it on its new 1300/1350 engine with a 50 HP gain! Apparently there is some truth to the theory...
From Mercs website; http://mercuryracing.com/1300/
"Air Intake
The horsepower these engines boast is directly related to the way they breathe. The air induction. As is typical for most sterndrives, the 1300 breathes ambient air from the engine room. The 1350, on the other hand, breathes cooler outside air through a direct air induction system. It’s that cooler air that gives it the extra boost of 50 hp. The air induction system does require computer aided design (CAD) integration with your boat."
As for the water ingestion a little mist, rain or spray would prolly never make it through all of the ducting and in to the TB. Especially at the speeds you would be running when it is raining. Just have a low spot in the duct and a small drain hole, 1/4" or so will be plenty. Anyway, I have ran engines with water and water/methanol injection so again a little spray will not hurt a thing.
Now, if you stuff the boat and the wall of water hits the scoop that would be a different story....
And it seems you have covered the engine compartment ventilation needs as well so again, awesome project!:USA:
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Offshore Ginger
New member
When i was at Skater we used those type of vents on the deck or Butlers as they were called .
jeffswav
New member
Boy those inlets may have made this project a little easier. I made the inside portion from scratch :ack2:. I have seen that project on mwbp and I forgot all about how you did those vents. The scoops have been a real pain but they are looking better.
MOBILEMERCMAN
Founding Member / Competitor
I thought those were called NACA ducts.
MOBILEMERCMAN
Founding Member / Competitor
Just remember. Air in, Air out.
Offshore Ginger
New member
Talk about airrrrrrrrrrrrr:rofl::rofl::rofl::rofl::rofl:Jim , yes those vents are NACA ducts and had Butler printed on them or should i say stamped in them and that is why... i call them Butler's , and the vents that we used at Skater were made of some type of black plastic which were glassed in under the deck and Jim only you might remember this name which is is John Sherlock who once tried using those vents on a 40 Skater to push air into the steps to give the hull more lift on one of the old Don Q rum boats .
MOBILEMERCMAN
Founding Member / Competitor
I remember him although, I didn't know him personally.
26 Spyder
New member
Yes, they are called NACA ducts.
I bought a plastic NACA duct from a circle track car catalog, and I made molds from it so I could duplicate them in fiberglass to make them easier to graft in.
There are many different shapes and sizes available. So the custom possibilities are endless.
Cigarette uses a similar style vent on some of their boats. and I am sure a few other manufactures as well.
jeffswav
New member
Here are the latest pics. I am making better progress on the vents. The inline air sander broke again and I started sanding by hand and I am not blowing through (as much). I should have sanded it by hand from the begining.
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rchevelle71
New member
looks good!!
Offshore Ginger
New member
Jeff , sometimes stuff like this is a lot of work put the rewards are even better because you did it yourself and with that in mind pat your self on the back.................L@@KIN G@@D:sifone:
jeffswav
New member
Thanks Guys, I am caught up with work until next week. I will be working on it tomorow and I may get it put back together this weekend. To bad the rivers are up or we may have tried it out on Sunday. The nearest lake is about a 1 1/2 hours and may not have enough time to do that.
jeffswav
New member
OK, here is a project update. I installed the Ram Air and ran it today. It was very hot and humid, very high heat index. I would say the ram air is about a 2MPH upgrade and the 3" raised x about a 4MPH upgrade. I ran about the same speed today (considering the temps) as I ran with the hatch and air cleaner off on the test runs.
Offshore Ginger
New member
Jeff , that is sooooooooooo c@@l and to think most of it was just a little hard work with no expensive motor upgrade's .:driving:
jeffswav
New member
Thanks Artie, I am not real crazy about adding more power to the stock Bravo. I am running about 500HP at this point. There seems to be a lot of ways to squeak out speed with the setup. Even if somthing only adds a 1/2 or 1 MPH it adds up when you do them all. Next winter I may get rid of those tiny bubbles on the hull and do a little wet sanding.
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