The carbs are the early CD type, not CD-2. They are the simple ones with jets that adjust from below instead of needles from above. The diaphragms were replaced last year but the low idle vacuum has been with the car since before this rebuild so I don't think it is something I just created. It is probably something that has been wrong with the carbs/manifold for as long as we have had the car.
My plan at this point is to bring the engine to temperature again, then loosen the manifolds to gain access to the head studs and re-torque them. After that I can take the intake manifold to the bench complete with the carbs and give them a once over.
I made sure both the intake manifold and header had flat flange surfaces and I even built up the header flange thickness to match the intake flange thickness for uniform clamping. I am just confused.
I guess while the engine is idling to temperature I will try ether or propane around the intake to see if I can find a leak. It didn't work last time but it is certainly worth trying again.
Doug L.
--Previous Message--
: I do iron head/block engines hot.
:
: If you can't find any external vacuum
: leaks, it could very well be due to an
: internal leak in one of the carbs,
: depending on exactly what carbs are
: fitted. For example, if they have
: throttle plate bypass valves, one could
: be sticking open and would give high
: idle and low vacuum. Some have the
: internal decell valve diaphragms,
: different flange spacers/gaskets etc.
: Can you drop the idle if you back the
: idle screws out all the way?
: Glen
:
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