I put this in someone elses thread but as the hoses were for Katrina, I thought I'd copy it here too
so the engine side of things has either 16mm ID pipes (let's conveniently ignore the fact that they were 5/8" when new as they're marketed in metric terms now!) - that's the autochoke and the water pump rear inlet, or 13mm pipes - thermostat bypass and heater matrix.
there is a choice here - run 13mm hose and step up where required, or run 16mm hose and step down. I opted for 16mm and wish I'd gone with 13mm as I have a modified system and end up with two pipes by the distributor (as a 5a would), which gets a bit tight.
so (assuming you go with 13mm hose) you need:
1. a 13mm 90 degree bend to come out of the heater (like this
2. a 13/13 plastic joiner (like this
) to connect to
3. about 1m of 13mm pipe (like this
) to go under the exhaust manifold to
4. another 13/13 plastic joiner to connect to
5. a 16/13 reducer (like this
) to connect to the rear of the water pump.
6. a straight 13mm pipe can come from the other heater matrix connection, along the top of the inlet manifold and with a 90 degree plastic joiner, go round the dizzy to the thermostat bypass connection. If you have an autochoke, you need to step-up both 13mm to 16mm at the carb with 16/13 reducer hoses and 13mm joiners.
this pic isn't much good for reference to the above because I have an autochoke, inlet manifold tapping and top inlet on the water pump. I also went with a 90 degree silicone hose to go round the dizzy.
the other part of the system is the connections to and from the rad.
the thermostat output is 45mm, so this needs
7. a reducer to get from 45mm to the 38mm of the top pipe (like this
at the other end of the top pipe you need
8. a 90 degree reducer bend to get from the 38mm down to the rad pipe 35mm (like this
the bottom pipe is a bit more complicated. First, the water pump outlet and bottom pipe are 38mm but (going from past accounts - I haven't actually fitted this bit yet) you need
9. a 90 degree AND a 45 degree pipe to get the correct angles (looks to me as if they will need quite a bit of trimming)
you can't get plastic joiners this big, so you need
10. a short alloy 38mm joiner like this
11. the bottom pipe to rad is another 90 degree 38/35mm reducer elbow.
Obviously I have fitted new clips all round - and with the number of joints I think that's about 26!!