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

[George Lyle <glyle@xxxxxxxxxxxxx>]

On Mon, 1 Oct 2001, craig k wrote:

> >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?

Well, that would be me!  :)

Placing a restriction in the path won't speed up flow unless flow goes
sonic in the throat, which is far from the case here!

whether to put the restriciton early or late in the path would seem to be
a "flip the coin" decision.  The restriction seems to be the same either
way.  The only difference is that putting the small hole on the left will
result in greater pressure fluctuation in the heat riser than putting the
small hole on the right.  Perhaps this pulsing will result in a
self-cleaning action.

Just a theory...

George Lyle