SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: 1972Challenger on September 15, 2010, 07:19:08 PM

Title: mounting the air scoop
Post by: 1972Challenger on September 15, 2010, 07:19:08 PM
ok so im just looking around and some guys have the scoop backwards.... is that a reason for this??? or is it just looks???
Title: Re: Re: mounting the air scoop
Post by: Nordie on September 15, 2010, 07:51:29 PM
2 reasons mine is backwards...number one is I have taken a couple of accidental roosts from other boats...ok ok one was intentional...number two is I dont run a flame arrestor
Title: Re: mounting the air scoop
Post by: 1972Challenger on September 15, 2010, 07:54:48 PM
sooo if you mite "accidently" get roosted, mount it backwards.... what about preformance??
Title: Re: mounting the air scoop
Post by: SuperJet on September 15, 2010, 08:29:44 PM
sooo if you mite "accidently" get roosted, mount it backwards.... what about preformance??

 there is no ill effect to performance if you mount it backwards. I also run mine backwards
Title: Re: Re: mounting the air scoop
Post by: Nordie on September 15, 2010, 08:30:07 PM
Actually never noticed a difference at all....i might add I think they look better fwd
Title: Re: mounting the air scoop
Post by: 76 Bonneville on September 15, 2010, 08:51:01 PM
I agree w/ Nordie, they look better forward.
Years ago I had a friend who ran the scoop forward w/ no spark arrestor. Every once in a while it would send a fire ball right up the center between the 4 of us. We always leaned to the outside when the boat was being started.
Title: Re: mounting the air scoop
Post by: GT Jets on September 15, 2010, 09:48:11 PM
Less engine noise with them backward too... ;)

GT
Title: Re: mounting the air scoop
Post by: IRRebel on September 15, 2010, 11:53:22 PM
It IS possible to get roosted with them backwards........I did it to Nick unintentionally. 'twas ok, but coulda been bad,  :-[

How it works out is this. Legally, if you have flame arrestors, OK to run 'em either way. Without flame arrestors, they HAVE to be faced away from the engine compartment on open engine boats. Closed engine compartments, you have no choice, they gotta be there.

In practice, Circle Racing boats run 'em that way because theres a LOT of water spraying around everywhere, at least that's what I think. Drag racers don't have this issue, really.

FWIW, my honest opninion is that while it takes around 10-15 HP difference to feel it "seat-of-the-pants" in a street or drag car, with NO OTHER CHANGES, it would take at least a 50 HP difference to feel it in these jet boats. You're not gonna see that with which direction the scoop is pointed.........

Ray

Title: Re: mounting the air scoop
Post by: 2Screwed on September 16, 2010, 08:27:18 AM
I always wondered the same thing until I drove my boat with it forward and with it backward;

1.  It is very noisy facing forward.  When the secondaries open, sounds like a supercharger or whistle blowing in your ears.  Facing towards the rear, it is not so loud.

2.  It is hard to keep it facing forward when going in rough water or fast.  It tends to want to move to the left or right, but if it starts facing backwards, it stays that direction.

3.  Water entry into the engine is a concern when facing forward, but I never had a problem with people spraying me.  ;D
Title: Re: mounting the air scoop
Post by: flytime on September 16, 2010, 06:27:41 PM
3.  Water entry into the engine is a concern when facing forward, but I never had a problem with people spraying me.  ;D

As long as you stay in front of Ray you should be O.K.  ;)
Title: Re: mounting the air scoop
Post by: 1972Challenger on September 16, 2010, 06:58:55 PM
oo so they turn??  that would suck.. and look funny if you saw a boat with the scoop to the right or left
Title: Re: mounting the air scoop
Post by: IRRebel on September 16, 2010, 11:59:38 PM
As long as you stay in front of Ray you should be O.K.  ;)

Yeah, that HAS happened more than once,  :sly: N8, Gil, Nick, and I think I got Skip once.

Ray
Title: Re: mounting the air scoop
Post by: Brendella Pickle on September 17, 2010, 06:59:47 AM
oo so they turn??  that would suck.. and look funny if you saw a boat with the scoop to the right or left

They shouldn't turn if you have them mounted correctly.
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