Two Stk

[Dean Pappas]

Re-reading some of the thread, I remember that some (and I mean only some)
of my CL Stunt buddies swear that a plastic venturi runs better than an aluminum one.
I can't say I've seen the difference in my Stunt stuff, and whan I make a Delrin venturi, it's cause it cuts easily in the teeny-weeny toy lathe.

Dean Pappas
Sr. Design Engineer
Kodeos Communications
111 Corporate Blvd.
South Plainfield, N.J. 07080
(908) 222-7817 phone
(908) 222-2392 fax
d.pappas at kodeos.com


-----Original Message-----
From: discussion-request at nsrca.org
[mailto:discussion-request at nsrca.org]On Behalf Of Bob Richards
Sent: Tuesday, March 01, 2005 8:53 AM
To: discussion at nsrca.org
Subject: Re: Two Stk


I've heard of heating the fuel before it goes to the
carb (on automobiles) improves the vaporization and
can increase mileage. Don't know if it is true, but
sounds plausible.

I believe the majority of the vaporazation in our
engines occurs in the crankcase (two strokes), not in
the carb. I also think that this process helps cool
the engine internally, especially the piston.

This reminds me of a problem I had with a generator a
couple of years ago. Ran fine for about 30 minutes,
then would start running erratic. Finally, I figured
out it was carb ice. Click the link below to see the
quick fix for it. Ran a piece of dryer vent from the
cylinder head around to the intake. Got me through the
2003 ice storm, no power for several days.

http://www.toprudder.com/photos/feb03/carb_heat.jpg

Bob R.

--- Rcmaster199 at aol.com wrote:

>  
> The action of converting liquid fuel to a vapor in
> the venturi is a part of  
> the refrigeration cycle. It requires energy to do
> it, which comes from several 
>  sources. The most important source is the lower
> than ambient pressure as the 
>  piston drives to compression, but ambient air and
> crankcase heat contribute  
> also, once the engine has reached steady state.
> Insulating the carb body 
> places  different demands on these sources of
> vaporising energy. 
>  
> Potentially, it may reduce air temp further which
> may have a supecharging  
> effect. I think you are after improved sealing
> between the carb body and the  
> throttle barrel, but this could be an added benefit.
>  
> Interesting idea Nat
>  
> Matt
> In a message dated 2/28/2005 9:02:14 PM Eastern
> Standard Time,  
> natpenton at centurytel.net writes:
> 
> The carb is a potent refrigerator. Most carb case 
> heating comes from ambient 
> air, not from engine case conductance. The engine 
> crankcase though, should 
> be well ventilated. The  situation may be better
> with a plastic bushing for 
> mounting the carb to  engine case, although I have
> not done so.  Nat
> 
> ----- Original Message ----- 
> From:  _Dean  Pappas_ (mailto:d.pappas at kodeos.com)  
> To: _discussion at nsrca.org_
> (mailto:discussion at nsrca.org)  
> Sent: Monday, February 28, 2005 1:49  PM
> Subject: RE: Two Stk
> 
> 
> Did you turn down the carburettor boss to make a gap
> that's filled  with 
> vinyl?
> If  not, then it's an awfully thin bit of insulation
> that provided the 
> desired  effect.
> later,
>     Dean
>  
> Dean Pappas 
> 
> 
> 
>  
> 

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