*How to* engine hatch scoop
 

I fiberglassed the scoop onto my engine hatch tonight and figured I posted up some pics for everyone if they are ever thinking about do this to there boat.
Iam not really going to tell you step by step just take a look at the pics and you get an idea...I still need to do the body work once the resin is dry.

http://i126.photobucket.com/albums/p...r6/Boat107.jpg

http://i126.photobucket.com/albums/p...r6/Boat108.jpg

http://i126.photobucket.com/albums/p...r6/Boat109.jpg

http://i126.photobucket.com/albums/p...r6/Boat111.jpg

http://i126.photobucket.com/albums/p...r6/Boat115.jpg

http://i126.photobucket.com/albums/p...r6/Boat116.jpg

http://i126.photobucket.com/albums/p...r6/Boat117.jpg

http://i126.photobucket.com/albums/p...r6/Boat119.jpg

who'sscoop is that ?
what"s the overall height?

Looks like the Teague scoop? Nice choice anyway. It gets the opening up where there is good airflow. I wouldn't have cut the holes in the back though.....

Keith Eickert sells them...
34"long 17"wide 9"high
Iam not looking for a ram air effect iam just looking at bringing more fresh air into the bilge. So by putting 3 holes in the back side of the scoop iam sure it will effect the "ram air" but its better then running no scoop. I have seen many do this and figured I would jump on the bandwagon also :lolhit:

Cool, keep posting more of the project. I did a Ram Air kit on mine. I draw air from both sides of the boat. I gained about 1 1/2 MPH, every HP counts.

On faster boats it's very likely you can cram too much air into the engine compartment and blow the hatch off! Ask me how I know:drink: The holes are a good idea.

It's a job thats's for sure I can post pics but don't want to hijack your thread good luck with it a take your time.

OK, how do you know? I've seen them with the holes too before so maybe you do need them.

Good thread i was only thinking about doing a scoop hatch last week i am makeing a plug as this time havent got the scoop yet how much is the one you have there looks just right ,i have seen scoop hatches with flapps that that just hang shut and open when air presure builds up

crapr6
nice look...just a question...looks like you have a spare sea strainer on your bench. any chance its looking for a new home

Please do. I've been thinking about doing this for a year or so and pictures say a 1000 words.

Scoop looks great, you do need the holes. I have two scoops on my ride like the Raisen Bran commercial and they pack huge air at speed. The holes on the back release lots of air pressure. Kinda like a fart, pressure has to come out somewhere, right!:eek:

Something you know about finally:lolhit:

lol not a spare but that is going to making it's way into my boat once the weather breaks!! :coolcowboy:

I kinda figured the holes in the back would help out. That scoop is huge and will allow a ton of air into the engine compartment and there really isn't much ventege..(is that a word?) to release the air out. I just can't wait for the first time I stuff the boat and all that water makes it way into the scoop..Motor is going to love that :grinser010:

I'll post some more pics of me cutting out for the foam and vinyl to fit around the scoop tonight.

Did you glass it on the inside? Probably a good idea ............... Great job looks faster already!!!!!

Just for informations sake, I measured the air pressure inside my engine bay at 100mph. Now consider theres a 900hp blower motor in there sucking up air as fast as it can and four double vents on the transom and it still registered 11psi above atmospheric pressure.
Thats with three 2" hole in the back of the same design scoop as the one pictured above.
It was enough prssure to force air between the hatch and rear seat back cushions on my Daytona and actually blow them loose from the velcro that holds them in place.

As for the scoop, did you use any filler in the gap between the scoop and the hatch? If not, I highly recommend you fill the gaps with an epoxy filler from inside the scoop to keep the water out and aid in bonding the scoop to the hatch. If you store the boat in freezing temps and any water gets collected in the gap, you know you'll be redoing the job next summer.

Good advice. I made my own custom scoops, and when I glassed them on, I bedded the flanges down with 403 filler, then glassed both inside and out. I cut the hatch to fit the id of the scoop exactly, because I am going to have the big Eickert bonnets sticking into them.

I'm confused as to how you could get 11 psi in your engine compartment. The stagnation pressure of air (density=0.0025 lb-sec/ft^4) at 100 mph is only 0.2 psi. This, acting on a typical 8' x 8' hatch would be about 1840 lb of uplift on the hatch, which is obviously enough to cause a big problem. 11 psi would be 101,400 lb on your hatch. That would launch it somewhere into low earth orbit.

I have no idea. I am certainly no physics professor. I hooked up my lab scope to a pressure transducer that I tie wrapped to the hatch actuator and thats what it showed.

I may be wrong buy if we could get 11psi in the motor compartment by adding a large scoop would we need blowers!!!!

You may have been reading absolute pressure. Did you have a reference line to somewhere outside the engine compartment? If your elevation was somewhere around 4000 ft or so, this would be about right. Anyway, the boat woudn't hold 11 psi anyway without exploding. The bottom structure would, but decks and superstructure are usually designed for 3.5 psi or less. Even a residential 100 psf floor load is only 0.69 psi.

Here is a simple video to explain this delima

Part one

http://www.youtube.com/watch?v=0fy4TLMNb6s

Part two

http://www.youtube.com/watch?v=KDpPQ_PfLXU&NR=1

That guy's a character. I bet his class would have been quite interesting.

or possibly I had the scale incorrectly set and it was 1 point 1 psi?

hood scoop
 

Hello I was just wondering what the length, height, and width of the scoop is that you are using I have an 87 scarab excell that im in the process of buy a scoop for it. Yours looks great and any advise would be greatly appreciate. thank you for the help.

Keith Eickert sells them...
34"long 17"wide 9"high


I hurt my back so no work being done on the boat right now...

Swan I have a scoop for sale, it looks almost identical it just doesn't have the raised section at the rear I can send you some pics. No price set, make an offer!

Bigmike i purchased one last night or i would have been interested in buying yours. sorry if i hear of anyone wanting one of these i will let them know youve got one thanks for all the help.

Some people have asked to see mine I didn't want to hijack this thread so here it is.

http://www.offshoreonly.com/forums/c...ml#post3353806

Please send me some pics of the scoop. [email protected]
Thanks

Carter38 that came out awesome!

I have the same scoop on my Daytona 26 - BUT I have mine sealed to the flame arrestor.
I installed a piece of clear Lexan installed flush with the hatch inside the scoop with a hole cut in it that goes over the flame arrestor and mates with a collar around the flame arrestor.
This keeps the air from pressurizing the engine compartment.
https://cimg2.ibsrv.net/gimg/www.off...49e7fb44e7.jpg

https://cimg4.ibsrv.net/gimg/www.off...c011b2749a.jpg
https://cimg8.ibsrv.net/gimg/www.off...d5a61902d0.jpg


Their are vents on the top of the transom.
I have the throttle body sealed to the scoop to try and control the pressure that tries to blow the hatch open.
The previous owner had this happen at least once. This is a NEW hatch.
ALSO the ram air is VERY noticeable at speeds over 100 MPH.
even with that attempt to seal it the back seat cushions still get blown off onto the floor.