Half-dude (10/12/2016)
I remember reading about who the Y-block funnels exhaust gases through the intake manifold to help heat up everything and get the car going which I guess was a new idea then at least how it was written about. I was wondering if the heat riser has anything to do with that.
Yes, the heat riser has everything to do with the diversion of exhaust gases from the passenger side cylinder head exhaust manifold, through the bottom of the intake manifold and then into the driver's side exhaust cylinder head, and then into the driver's side exhaust manifold. The heat riser spring provides resistance to the opening of the plate that restricts the flow of exhaust gases out the passenger side header. As engine speed increases, the volume (quantity) and force of exhaust gases exiting the passenger side cylinder head increases and the heat riser valve opens against the spring pressure permitting the increased quantity of exhaust gases to flow out the passenger side exhaust manifold, through your cross-over pipe, and into and out the driver's side exhaust manifold, and into the exhaust header pipe and on to the muffler below.
Even if you have the heat riser wired in the open position, some exhaust gases will still likely flow from the passenger side cylinder head, through the bottom of the intake manifold, into one of the driver's side cylinder head exhaust ports, and then into the driver's side exhaust header and then out of the header and into the exhaust header pipe.
To restrict the quantity of exhaust gases passing under the carburetor (which otherwise burn the paint off the two exhaust cross-over branches of the intake manifold) some of us use the style of intake manifold gaskets that Ford supplied on some truck y-block engine application.
Here's a picture of the standard intake manifold gasket originally supplied by Ford for passenger car use. Click the link below.
http://www.ebay.com/itm/Fel-Pro-MS9361B1-Gaskets-Manifold-Intake-Ford-Mercury-Ford-Y-Block-Set-/331549408964?fits=Make%3AFord&hash=item4d31e27ec4:g:4I4AAOSwBLlU~~LQ&vxp=mtr Here's a picture of what Ford originally supplied for use on some truck applications. Note the restrictions in the size of the center exhaust cross-over ports in the link below.
http://www.ebay.com/itm/FORD-CLUB-1955-1962-Y-BLOCK-INTAKE-MANIFOLD-GASKET-SET-9433-01-/360814069198?hash=item540231c5ce:g:cFYAAOxy6-tR-U~N&vxp=mtr Some of this is a lot easier to understand IF you have the opportunity to see how the y-block cylinder head is ported with regard to one exhaust port in each side of the engine.
Hope this helps.
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York