[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] Pump & tubes


On 22 Jun 99, at 7:22, Steven Ayres wrote:

> RobyB=> is anything special about the type 3 fuel pump?  
> 
> The Brazilian T1 pump works and is often found in T3s, though they do 
> not produce the T3-spec pressure of 5lbs. 

I didn't realize that the T3 asked for a different (higher ?) 
pressure than the T1&2. Why would that be? That pressure isn't really 
that important, is it? Doesn't it just have to be enough to provide 
enough flow through an open float valve and not so much that it can 
overwhelm a closed valve? That should allow a HUGE range.

Okay, I just pulled out my "Without Guesswork" and looked up the fuel 
pressure. It verified that the MAX pressure for the type 3 is 5 psi 
and the MAX pressure for type 1/2 is 3.5 psi. The minimun delivery 
capacity is the same for the two, but the footnote is interesting: 
Did you know that the type 3 carb uses a different float valve„+m±
actually SMALLER in diameter! The T1/2 float valve is 1.5mm dia while 
the T3 is 1.2mm. If I take the ratio of 1.5/1.2, then square it to 
get the ratio of the areas, then I have approximately the ratio of 5 
to 3.5.

So it seems that if you needed to go with a type 1 fuel pump (at 
3.5psi), It might be a good idea to go with type 1 float valves. Do 
they interchange?

Jim
-
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

-------------------------------------------------------------------
List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]