SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: nathan72 on June 08, 2009, 09:01:58 AM

Title: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 09:01:58 AM
the intake had ice all over it wen i got back in. i only ran it for 20 min. the motor temp was good and it ran grate.any help would be aprishiated
Title: Re: frozen tunnel ram ?
Post by: HDriderTH on June 08, 2009, 09:06:19 AM
.....oh shit
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 09:24:52 AM
has anyone had this happen to them?
Title: Re: frozen tunnel ram ?
Post by: JMS-1 on June 08, 2009, 09:28:02 AM
mine doesn't make ice, but it will get ice cold and covered with condensation even with it being 110 out. i have been told it is caused by the fuel atomization.
Title: Re: frozen tunnel ram ?
Post by: Sanger Pete on June 08, 2009, 09:40:01 AM
Sounds to me like it was doing what it's supposed to do--increase velocity and cool the gas/air mix. I've heard of them icing up, but have only personally had one get cold. What rpms were you running?
Title: Re: frozen tunnel ram ?
Post by: HDriderTH on June 08, 2009, 09:44:22 AM
It's a good thing Nat. Go with it....
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 09:51:21 AM
5500 it ran like a mofo. i got back and seen all that ice and freaked out a little. i guess it a good place to keep the beer
Title: Re: frozen tunnel ram ?
Post by: trmn8ter on June 08, 2009, 10:37:36 AM
MINE DOES IT ALL THE TIME, ITS ALL GOOD!  ;D
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 10:43:46 AM
thanks guys
Title: Re: frozen tunnel ram ?
Post by: BOOST on June 08, 2009, 04:57:07 PM
thanks guys
Mine does the same thing I heard it was a good.
Title: Re: frozen tunnel ram ?
Post by: osbo68 on June 08, 2009, 04:59:58 PM
Mine gets nice and frosty... it's supposed to... And I'm jealous of your RPM's...  O0
Title: Re: frozen tunnel ram ?
Post by: CHROMEY on June 08, 2009, 05:05:07 PM
did you forget to say your running alcohol?...lol  >:D
Title: Re: frozen tunnel ram ?
Post by: 75 fantasy on June 08, 2009, 05:58:19 PM
i love it when that happens!!!! sometime if my boat's not running right the tunnel ram won't frost-up though!
Title: Re: frozen tunnel ram ?
Post by: SLCKREG on June 08, 2009, 06:21:25 PM
What octane fuel were you runnin? My single 4 high rise would all but frost up, I always thought it was because I was running some 110.
Title: Re: frozen tunnel ram ?
Post by: TJS Nordic on June 08, 2009, 07:01:27 PM
When I was test running my BBC 8-71 Bugcatcher EFI set up the top of the bugcatcher got real cold and almost frosted up as well. Got real cold.
T.J.
Title: Re: frozen tunnel ram ?
Post by: Brad @ SCJB on June 08, 2009, 08:03:15 PM
think of it as a cold air intake  ;D
Title: Re: frozen tunnel ram ?
Post by: RTriebess on June 08, 2009, 09:05:30 PM
normal condition
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 10:05:37 PM
What octane fuel were you runnin? My single 4 high rise would all but frost up, I always thought it was because I was running some 110.
      92 octane... the first time i have ben over 80 in a boat im still shaking
Title: Re: frozen tunnel ram ?
Post by: GT Jets on June 08, 2009, 10:13:05 PM
The correct term for this phenominon is called "latent heat of vaporization" (look it up) ;D..

The temp of the air charge is actually being lowered by the vaporized fuel, the fuel does not really matter. I am trying to find a picture zi have of a Marathon boat after a hard run, it had 3" icicles swept rearward from the tunnel ram, it was badass...

The same thing will happen on my small blocks air gap, but to less of an extreme (the manifold is too close to the heat of the heads to make much ice.).

GT
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 10:24:11 PM
im glad its a good thing. it looked like the inside of a old ass freezer
Title: Re: frozen tunnel ram ?
Post by: GT Jets on June 08, 2009, 10:29:16 PM
im glad its a good thing. it looked like the inside of a old ass freezer

What do you do with an "ass freezer"? LOL

GT
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 08, 2009, 11:48:20 PM
come on GT you remember  ;D ;D ;D
Title: Re: frozen tunnel ram ?
Post by: IRRebel on June 08, 2009, 11:52:50 PM
Lol Mine gets a little frosty, but the carbs still need a LOT of tuning from someone smarter about it than me, thedn it'll prolly ice up pretty good. Plugs say I'm running a little lean, (White to very light grey). I'll get Terry on it when we hook up again.

Ray
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 09, 2009, 12:08:22 AM
it was way fat so i jeted it down to #72s and #74s the carbs are 750s. the plugs are a nice light root beer ish.
Title: Re: frozen tunnel ram ?
Post by: IRRebel on June 09, 2009, 04:03:04 AM
it was way fat so i jeted it down to #72s and #74s the carbs are 750s. the plugs are a nice light root beer ish.

So are my carbs (750's). Sounds like you got it about right, I don't yet. Have no idea what's in them yet. It's running, running good, just needs all those little touches to see her capability. But dun worry about the frosting. I was warned about that putting on the tunnel in the first place. Engines like cool mixtures methinks, at least that's the theory, ask the Honda guys.......

Ray
Title: Re: frozen tunnel ram ?
Post by: walshmotorsports on June 17, 2009, 01:06:27 AM
  Thats all good when I had a blown deal in my v-drive cruiser I would make mid week runs up and down Parker and you could dig your finger nails in the frost on the blower......Awsome!
Title: Re: frozen tunnel ram ?
Post by: jet boat performance on June 17, 2009, 07:32:09 AM
Same reason your BBQ tank "sweats" when your BBq'in , Common on Trams and blowers etc  Tom

ps .. Cool fuel antomizes better like Terry said its a "good thing"
Title: Re: frozen tunnel ram ?
Post by: GT Jets on June 17, 2009, 08:05:31 AM
Same reason your BBQ tank "sweats" when your BBq'in , Common on Trams and blowers etc  Tom

ps .. Cool fuel antomizes better like Terry said its a "good thing"

Actually its "warm fuel and cold air", just really hard to achieve... ;)

Our race boat had a fuel cooler that was actually running hot water, right before the carb, warmed the fuel just before it hit the motor, then we had a 2" open spacer under the carb.

It ran very hard and the tuneability was incredible (ran richer when cold because of the puddling fuel). :thumbup:

Old Sprint car trick (mechanically fuel injected) :sly:

GT
Title: Re: frozen tunnel ram ?
Post by: nathan72 on June 17, 2009, 11:31:39 AM
it a slushie machine  ;D it made about 1/2 inch of ice all the way around and about 2 inches in the back. wen it melted it made a mess the water settled around the bottom of the intake and left little nasty rings
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