yes bypass is gold pipe to gold pipe with nothing else in this pipework.
has the new cnc stat housing got a provision for a 16mm hose..? if not we need to locate a suitable point for the bottle return to feed into.
and where would that be? Can they be connected into one?
There's currently no provision built into or onto the engine at the the outlet or Inlet end for a bypass pipe.
Driving 'The Fat One'
Theres no 16mm connection on the cnc stat pipe and theres no room there to fit a plastic thermostat housing with two inlets .Too much supercharger pipework in the way .
What about fitting the expansion bottle return pipe by way of a T into the bypass pipe ? After all thats the way it runs now ?
On a related matter , The casting shown in photo ,post 48 appears to have a blanking plug where the bypass elbow would fit . ( need to take it off to fully check but that appears to be the case )
Does anyone know a source for the elbows ? If found the existing back plate could be modified .
I've just checked mine and yes there's a downward facing spigot which looks like it could be drilled and tapped.
The plug on the bottom of the bolted water outlet at the back of the head is just pressed in. You can specify one of the products advertised here whether you want it with the bypass outlet on the bottom or without - the plug would be pressed in instead. The issue of that particular outlet is that it only offers thread for one temp sensor while we do have two in there. It looks far more feasible to modify our water outlet with the knee for a 16mm water hose.
You could add a 16mm elbow to the housing, I haven't had the opportunity to study at length the clearances for the Rotrex plumbing, but I feel with a little patience you could rework the housing to accept something suitable.
Found this from SBD Motorsport. I find the second paragraph quite interesting as it may be the cooling strategy Caterham originally used although they also don't use the bypass hose.
The cooling system shown is the design as used by SBD Motorsport, when using a mechanical water pump. The most important part of the cooling system is the orange recirculation pipe. When the thermostat is shut, the coolant passes through the engine, reaches the closed thermostat, the coolant flow is then directed through the front of the cylinder head to the water outlet on the underside of the inlet manifold and the coolant is then drawn back in to the engine by the water pump. This keeps the coolant flowing through the engine maintaining an even temperature. As the temperature rises within the engine, the thermostat slowly opens allowing the coolant to pass into the main cooling system to the radiator. The thermostat is a 2-part stat and as the thermostat slowly opens, the second part of the stat begins to slowly close the entry into the recirculation part of the cooling system and as the temperature begins to fall again, the thermostat begins to slowly shut. This maintains an even temperature throughout the engine.
Important Note: Some engines used in specific race car championships (Formula 3, etc) do not use thermostats. They carry out extensive testing, design the radiators and cooling system around their design and quite often change the water pump design and even on occasions use restrictors. This is not something recommended for a single user. If you get your cooling system design wrong, the water could flow too fast or too slow causing hot and cold spots within the engine, creating damage to the engine itself. In many cases this problem may not be visible straight away and may become more apparent over long periods of time. We do not recommend this set up.
The most common mistake when designing a cooling system is to misunderstand the flow of the cooling system itself. The mistake normally made is when connecting one of the following: the header tank outlet (green), the heater outlet (red) and the recirculation outlet (orange). These pipes must separately be fed into the blue water pipe shown flowing from the radiator outlet and going towards the back of the water pump. DO NOT attempt to T any of the pipes together, this will completely destroy the water flow causing a major problem with your cooling system.
Running a road car with no thermostat control in cooling ot oil circuits is madness.
Whilst space is very limited it does shows a lack of understanding from CC in removing the bypass circuit and using it to feed the header tank into,
Love to get my head under the bonnet,
Ti 7 could you BM me as I think were not too far apart