Thanks Zukizzy

    I appeciate the input and you're absolutely right, if this ever goes into something that will fly it will have an alternate air source. My Dad was an accident investigator on aircraft for many years so cowardice is the greater part of valour on stuff like this.
    I'm just surprised to get Rhinoman's report on the carb ice. With the Airboat its a problem because of the high humidity and variable tempatures on the water. The possibility of carb ice is quite high and I was hoping to avoid it without putting carb heat on the darn thing.

Then again I really hate paddling so I should look into it.

Zag

Thanks Zukizzy

    I appeciate the input and you're absolutely right, if this ever goes into something that will fly it will have an alternate air source. My Dad was an accident investigator on aircraft for many years so cowardice is the greater part of valour on stuff like this.
    I'm just surprised to get Rhinoman's report on the carb ice. With the Airboat its a problem because of the high humidity and variable tempatures on the water. The possibility of carb ice is quite high and I was hoping to avoid it without putting carb heat on the darn thing.

Then again I really hate paddling so I should look into it.

Zag

Paddle??? have a drink check the oil take a swim or not if there are gators and it will fire right up. doesn't take long to melt that ice when you remove the low preasure and intruduce heat from the engine. VWs that ran Solexes in a dual configuration would take off the carb base heat cause cold air makes more power. Problem was they would not run well at idle or after running a while and the problem was on again off again. by the time you got the air cleaner off there was no ice. Nobody believed us when we would tell them to add the base heat. but were all shocked when a prob they had chased for years went away after adding base heat. I once drew thru a holley 4 barrel into a turbo and then a 3700cc corvair. It would freeze Ice on the outside of the carb. went like He!! on the strip but would not idle after running a while.

OK that is enough
Wayne

 Ã‚    Come on I was jokin about the paddling, and gators in Alberta, they'd need parkas.
    All joking aside I agree with what you're saying and I've seen similar examples. With the airboat its operating on the rivers that actually worries me, sometimes the current makes waiting an unviable option.
    What I will probly look into is using the coolant log on the top of the manifold to heat the carb body with a direct connection of some kind. The aircraft application if it ever happens must have an alternate air source as well.
    I know what you mean about ice forming on the carb body. Back when I was young and foolish I ran a 360 Sprint Car with Hillborne injection and alcohol fuel. After a hard run of laps with the hood off there would be major frost build up......brings a new meaning to cool.

Zag

    Come on I was jokin about the paddling, and gators in Alberta, they'd need parkas.
    All joking aside I agree with what you're saying and I've seen similar examples. With the airboat its operating on the rivers that actually worries me, sometimes the current makes waiting an unviable option.
    What I will probly look into is using the coolant log on the top of the manifold to heat the carb body with a direct connection of some kind. The aircraft application if it ever happens must have an alternate air source as well.
    I know what you mean about ice forming on the carb body. Back when I was young and foolish I ran a 360 Sprint Car with Hillborne injection and alcohol fuel. After a hard run of laps with the hood off there would be major frost build up......brings a new meaning to cool.

Zag

Alberta??? holy cow I think air boat I think the glades. I change my story save all that heat for the cabin. you are gonna need it.

thanks
Wayne

If I'm not mistaken, even a port injection
EFI system can get some iceing if the
conditions are just right, the low pressure,
or the air acceleration (read wind chill factor)
could cause this with the right % humidity

Wild

Alright, quit pikn on duh red neck from up here in oil country.....or was that blonde haired, blue eyed arab...anyway it ain't that bad Zukizzy, today it was 19 degrees C (68F). Besides that means no gators or killer bees.
    "Wild" theoricicallyyou're correct and even injected aircraft are required to have carb heat. That said my experience has been direct port injected engines don't have any real venturi's and I have never heard of a real life example of "Carb Ice" even on FI aircraft. I have heard and seen the air intakes choked off with ice on the cowl though.
   Thats the nice thing about blow through turbos, preheat.

Last joke of the day...

Whats the propeller on an airplane for?
Keeps the pilot cool....don't beleive me?

Watch him sweat if it stops!!!  hahaha

Zag

Last joke of the day...

Whats the propeller on an airplane for?
Keeps the pilot cool....don't beleive me?

Watch him sweat if it stops!!!  hahaha

Zag

LOL
This thread as been all Greek to me but I get this part.

If I'm not mistaken, even a port injection
EFI system can get some iceing if the
conditions are just right, the low pressure,
or the air acceleration (read wind chill factor)
could cause this with the right % humidity

Wild

I wondered that because there is no warm air provision on the TBI system. My guess is that its so the mainifold air temp sensor always measures ambient temperature (or close enough to it) otherwise they'd need another temp sensor to determine air temp to be able to apply corrections to the pressure sensor.

     I think you're right Rhinoman. I know some of the Boschs
multi port systems do have 2 sensors (1) in the air box and (1) in the manifold and the computer averages the temps.
    By the same token it would take some eeexxxttreme conditions to get ice in the intake on most injection systems.

Zag

Rhino, the TBI system on my 89
Kick has coolant flowing thru the
base of the Throttle body.

Oddly enough, when I was running
a 160* thermostat, I was watching the
IAT (intake air temp) on the laptop screen
watching the MegaSquirt do it's thing, and
then looked at it after I changed to a 180*
thermostat and the IAT was within 2-3* of
the previous temp. And to further compound
this oddity, when I checked the temp of the
160* thermostat it really was opening at 140*

No wonder I froze my buns off going to Moab
in 2004, I could barely get warm air out of the
heater, it's a little better with the stock Thermo
back in, but I think the heater needs a cleaning

Wild

Heeeeyyy guys
   
    The cam just arrived...226 degrees duration/.395" lift.
Hope to get it installed this weekend or early nest week.

    I'll let you know how it works...

Zag

 

for grinns, do you know the stock cam specs

Wild

The stock specs are (according to what I can find out)...

200 degrees duration
350" lift

New cam should (mathmatically)
- peak power |removethispart|@ 6300 rpm
- peak torque |removethispart|@ 4800rpm

Now I need to get it installed and find out if the math is right.

Zag

If I'm not mistaken, even a port injection
EFI system can get some iceing if the
conditions are just right, the low pressure,
or the air acceleration (read wind chill factor)
could cause this with the right % humidity

Wild

Darrin you are exacly right. with the engine running pretty fast and the throttle butterfly only open slightly you have fast moving air going past the butterfly and expanding rapidly. this Expansion can cause Icing in even moderate temps. There is records of Icing happening in 70* wheather. William Wynn had a crash with a new pilot who forgot to turn on the carb heat on final Iced and came in short. In Florida in June I think but temps around 70*. The NTSB said engine failure but after salvaging the wreckage the engine started and ran with no mods. but the carb heat lever was still in the off position. You ever noticed how cold your propane bottle gets when you let out propane? That is Expansion cooling and why all intakes have some form of heat engineered into them. even if it is just ambient from the exhaust manifold.

Wow I can ramble
Wayne

Rhino, the TBI system on my 89
Kick has coolant flowing thru the
base of the Throttle body.

Oddly enough, when I was running
a 160* thermostat, I was watching the
IAT (intake air temp) on the laptop screen
watching the MegaSquirt do it's thing, and
then looked at it after I changed to a 180*
thermostat and the IAT was within 2-3* of
the previous temp. And to further compound
this oddity, when I checked the temp of the
160* thermostat it really was opening at 140*

Wild

Thats a good point the intake manifold is heated. Out of interest how much different is IAT to ambient?
Edit: of course your air is passing through a turbo and an intercooler so it could be quite different to stock.