Guide Guide: Laing DDC Pump mod 2 (image heavy).

Here is my second mod for the LAING DDC Pump. I decided to remove the 1/4 BSP threads that it was manufactured with and replace them with 1/4" BSP barbs so the pump could accept 1/2” tubing. I decided to ease the flow by placing the intake on the top.

Here some stuff you’ll need:
Female-Female 1/4" BSP connector – Mine is from RS (www.rswww.co.uk).
2 1/4" BSP barbs, your choice of style.
Two-part Epoxy glue – hardware shop.
Two-part Epoxy putty – modelling shop or car stuff shop.
Car body filler (nasty stuff) – Car stuff shop, hardware shop.
Spray paint of your choice (and undercoat/primer) – I chose metallic black, but it’s up to you.
Alcohol or meths

Tools:
M11 – M12 Die
¼ BSP Tap
Files
Hacksaw
Sandpaper
Drill bits – smallish, 7mm and 11.4mm
Screwdriver (star bits)

To start with remove the screws on the bottom of the pump.


This allows you to split the pump in half, it’s the top half we want to work on.


Drill a small pilot hole in the top where the intake goes the top of the impeller. Then drill a larger 11.4mm hole which is the right size to tap to 1/4 BSP.


Tap to 1/4 BSP very carfully as the plastic is quite thin and weak at the top.


I sawed off the 1/4 BSP threads leaving a little a short piece of pipe from the pump exaust. This was part of my cunning plan to give the connection some extra strength.


Once cut off I drilled out the exaust to 7mm to clean it out and increase to flow a bit. My cunning plan (from my previous pump mod) to get extra strength in the connection was to cut a thread (about M11 or M12) on the pipe so the 2-part epoxy glue I used would have a good mechanical bond with the pipe and the thread of the female 1/4" BSP connecter as in the diagram below.


Threaded.


Clean up the end of the barb so it’s nice and smooth.


Screw the barb it into the top of the pump making sure it’s clear of the impeller.


Using a two-part epoxy glue (I used araldite) glue the barb in pace making sure there’s glue all the way round to create a seal.


Assemble the pump making sure the o-ring is seated properly. Using the car body filler (a nasty smelling two part epoxy stuff) fill in the top of the pump to give the barb some support, be sure to use plenty; the excess can be sanded off later.


Then sand of the excess car body filler to create a smooth surface ready for painting.


Mask off the barbs and clean with alcohol prior to painting.


Spray with a primer (mine was grey, it comes in various colours). Leaving it to dry for the manufactures recommended time.


Then I sprayed with gloss black as an under coat to the metallic.


Then I sprayed the top coat, in my case metallic black, but the choice is yours.


Here’s the finished product.


And a comparison with the first pump mod I did.



Any comments are welcome, I'm learning too

Hope you liked it,

Jimbo

 

Looks pretty good wish I had the spare $ for a wc system.

 

I see you finally gave in and did the mod to the intake.. Still thinking of making my intake larger if i can

 

Supra55, Thanks... I save up my money for the WC, It's hard when I'm trying to save for a house!

SpaceRaver, yeah, I've got one of each now, two loops in my rig, when I finallly finish building it.

Jimbo

 

Sweet mod, looks great! does it perform as you intended??
Jaz_knos

 

JazX101, dunno yet, I'm going to test it outside when the weather get a bit better... I'll post the results, maybe even a video.

Jimbo

 

yup, sweet mod, man