I experimented with the timing, idle speed, looked for vacuum leaks, and finally tweaked the mixture a bit. I found no leaks using propane passed over/around all the joints, gaskets, throttle shafts, etc. No leaks were found. Following that I decided to play with the mixture just a tiny bit. I didn't want to do a complete tune up yet. The end result was a more stable idle at about 10-11" of mercury. That may not be the 13" Ted said I would get but it was significantly better than the 6" I had yesterday. This time the car survived its round the block trip without stalling. BTW, the dizzy does have vacuum advance but I have been doing a lot of this work with the line disconnected and plugged.
Not stalling is a good thing. The engine is still very tight and re-starting (even hot) takes a lot out of the battery. I think I may finally invest in a gear reduction starter.
Anyway, I will plan on pulling the manifolds off later this week and re-torquing the head followed by checking the carbs out carefully on the bench finally a mixture adjustment.
I am not 100% satisfied at this point but I am certainly MUCH happier than I was this morning.
Thanks to all for your help and advice. I may be back for more advice on this in a day or so.
Doug L.
--Previous Message--
: SOunds like you have a handle on it.
: Going the right way. Don't forget to
: check the throttle shafts for air leaks
: !
: Mark
:
: --Previous Message--
: What ignition timing are you using?
: Will
: probably want quite a bit for a decent
: idle/idle vacuum. I find that my mk2
: engine (stock 270 cam) likes 16 - 17º
: for highest vacuum (it helps that I can
: read the vac and control the timing
: from a laptop) and I'd expect a wilder
: cam to want a bit more.
:
: Does the distributor have vacuum
: advance?
:
: Cheers
:
: Nick
:
: --Previous Message--
: I can stall the engine if I back the
: idle
: screws out.
:
: 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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