Flavia 1800 water circuit

[philm]

Does anyone have any images or diagrams of the water circuit for a Flavia 1800, ideally an 1800 twin carb model. My Sport had a bit of a Heath Robinson setup which may or may not have lead to the failure of the engine in a previous owners hands. My rebuilt built 'pure' 1800 originally had a single carb so the heads have no take offs for heater or temp sensor.

My car had a hybrid engine with 2000cc heads on an 1800 block, there was a take off on the RH head for the heater feed (I believe it is feed, it heads off to the control valve) and a sensor boss on the LH head. There was no thermostat housing instead there was a T piece made from copper plumbing fittings! linking the head outlets through the manifolds back to the radiator. The other oddity is that the water pump has an outlet on the RHS (viewed from the drivers seat) which has been blanked off, I think that this can create an air pocket reducing pump efficiency.

So overall the system I had before on the hybrid;

Outlet from radiator into pump.
Blanked off port on pump
Exit from pump down to cross over pipe into RH & LH heads
Exit heads through manifolds into T
RH head feeds heater direct from casting port
Heater returns to base of cooler
Bypass hose from cross over pipe into base of cooler.
Sensor in LH head.

I am making up a new T with a take off for the heater and a boss for the sensor so I ca fire up in cofidence but I would dearly like to know what the blanked off port is for. I am thinkig of fitting a bleed point to it so I can vent any air.

[pbharcourt]

I think this may be the heater pipe, if blocked it would cause cavitation in the pump, do you have a photo?

[philm]

I am not sure it can be the heater feed as it would be supplying cooled water from the outlet of the radiator. I can see the cavitation issue though, so the question is what is it for? I will post an image tonight.

[philm]

After a bit of thought and a few sketches, I think this is how it should work;

Water returns from the head feeds into a central manifold (replaced by a copper plumbing T on my car)
The thermostat sits in this manifold with the heater feed after the 'stat (so the engine warms up as quickly as possible you do not want to feed the heater initially)
There is a bypass from before the 'stat back to the water pump (this is the pump port that was blocked off on my car) you need this bypass I think for initial running before the 'stat opens otherwise the flow circuit is dead ended against the 'stat until it opens. Although the heater could go before the stat to take advantage of the pressure drop through the 'stat to help flow through the heater core.

So I am making a new T with the requisite ports, although I do not need the bypass for flow I think the blanking plate allows a pocket of air to collect and affects pump output so I will run a bypass from my new T back to the pump. What I really need though is the correct manifold with 'stat. You can see the bypass port and partial hose run in the Flavia engine image in the Altorio Fulvia tome.