Re: [VB] Re: [T2] Heat riser Plugged SP conversion

[vwbus@xxxxxxxxx (craig k)]

>On Mon, 1 Oct 2001, Jake Raby wrote:

 one gasket of each is the correct way to do it, but the small ones are hard
 to find...This keeps the flow of the carbon going only one way, and it does
 not begin to collect in the center of the manifold.

>I think that the flow is maintained by the pressure difference between the
>RH exhaust port and the muffler.  I'd always assumed that the small hole
>gaskets were to restrict flow, but had never figured out why.  Does the
>small hole gasket go on the right or left hand side?

>George Lyle


Small hole on LEFT side, FIF.
Look at the RH exhaust port area; the muffler has a flange that comes
straight UP from the port and attaches to the heat riser. This side gets
the big hole gasket, as you want no restriction to flow here.
Left side exhaust port: notice that the leg from the heat riser connects to
a tube that reenters the muffler just ahead of the
tub where the fresh air hose connects - it sorta angles backwards, towards
the muffler. Little hole goes on this side, as you want to impede the flow
outta the riser somewhat. The flow of exhaust gasses out the LH exhaust
port will help pull the gasses through at the desired rate.
On contemplation, the small hole may not -restrict- flow at all ...
perhaps a venturi effect speeds it up!! Any physics majors on the list
wanna take a crack at it?
Either way, this setup  is the way the system was designed to work properly.

Please note that this is for modern engine/mufflers only - the 36 and 40 HP
crowd may have totally reversed situations for all know. Point to remember
is to follow the tubing to determine WHICH WAY flow is going R to L  or L
to R!

If you live in a VERY warm climate, you need to cut up a beer can and plug
the input side; think it overheats the fuel/air charge too much otherwise
(knock, vaporlock, i guess).

A good way to tell if a heat riser is plugged is to paint it with crappy
spraypaint... it will burn off as far up as you have free flow, up to a
point roughly near the middle (after that the gasses have cooled enough not
to cook many paints).

Craig K
70 Neunsitzer
65 Pritschenwagen