H Tube

[Malsprint]

I am in the process of fitting new heater and coolant hoses. I read in one of the post that the H tube on the heater line has a restrictor in it to help to force the flow through the heater core. Mine doesnt. Mine also looks a bit home made but that might be the factory finish!.

Should the H tube have a restricted diameter in one of the tube?

While we are at it. Is there any preference between the H tube and the more elaborate bypass tube system with the compression fitting and longer steel tubes. I assume that the H tube was fitted to later cars as a cheaper alternative. This is correct.

Are the two types interchangeable.

Thanks

[Carledo]

The restrictor is there, but not visible in either design as it's in the crossbar of the H.

It's there to stop airlocks in the system when the heater is on cold, allowing a small amount of water (or air) to pass through the heater hoses at all times.

The elaborate and complex design is (perhaps surprisingly) the later design of the 2. From around 76>

I have swapped these over from 1 style to the other, can't remember WHY now, but it IS possible.

Steve

[Richard the old one]

I will attach a photograph of a 1500 pipe which clearly shows the restriction in the pipework and a copy of the flow diagram for a 1500 engine.

[sprint95m]

Should the H tube have a restricted diameter in one of the tube?

While we are at it. Is there any preference between the H tube and the more elaborate bypass tube system with the compression fitting and longer steel tubes. I assume that the H tube was fitted to later cars as a cheaper alternative. This is correct.

Are the two types interchangeable.

Thanks

As Steve has said, they are interchangeable.

Back in the 90s, Sprintspares sold the H-piece c/w hoses as an upgrade for the later cars,
said later Sprints having the extended pipe work as standard.
If I had to choose one, I would go H piece (Chris Witor sells remade versions in stainless steel).
It is simpler.

However, I have went a different way by going for the heater input taken of the back of the cylinder
head…


Ian