Watercooling - going from large 12mm tube to smaller 8mm tube

[ERU]

I have a 12mm clear pipe going into a yellowish 8mm pipe (rad). Do you think this would cause any kind of constriction to the pressure of the water and affect performance to my water-cooling system? I am using an eheim 1250 pump.
The yellow looking 8mm pipe is the one coming from my radiator and would be a bugger to change.

[Shogun]

My advice would be to just try it and see what your temps are like.

[SilentDeath]

Sorry eru couldnt find those barbs today, I got mine from www.coolercases.co.uk, or over-clock.co.uk sell them if you need them still...

The yellowish pipe looks like normal 8mm pvc tubing covered in algy on the inside (you dont want that!!!) and probably exposed to sunlight (UV) and so also discoloured from that? If so cut it off and use new pipe. Can you get pic of where the pipe connects? looks like the shroud would be in the way, and thats rivited on? so you will need a drill to cut them out, probably...

Measure the ID and OD of the green pipe (looks more green than yellow in the pic!), it would be best, if you are going to use it to AVIOD youing the crappy blue adaptor. The blue adaptor looks like it will limit you to about 3 or 4mm ID which is too small for that pump. Idealy you would use a peice of copperor brass pipe (they have thin walls) to connect the two, and tehy should both stretch a bit when in hot water, which might help use bigger adaptor.

Next, the rad looks aluminuim, compleatly, and then sprayed silver - might be copper or brass underneath.. cant tell from pic. The radiator itself looks VERY restricive as each pass is in series not parrelell, almost would be like adding 20 meters of 8mm pipe instead of having almost no additional restriction of corrigated sheet style radiators (where each pass runs parrelell).

Id suggest if you cant swap the tubing to get another rad. If you want to keep it then know it will cause some corrosion when mixed with your blocks, and woud perform worse than a copper one anyway.. but apart from that it looks ok.. it should easly disiapate all the heat you will be putting in it.

If you keep the rad and use the green tubing, get a cloth and a long thing, and use it to clean the inside of the tubing, so its less green.

[ERU]

Cheers |SilentDeath|
The pipe is actually fine in terms of being clean it just looks like algy in the photo. You have a very good point about the blue adapter which didnt occur to me till you said
I'm not too bothered about mixing copper (it is copper and has been sprayed) and aluminuim as i beleive if i have the right addirives it should be ok. I'm actually about to make a trip down the scrap yard for a Ford Escort heater matrix and water radiator.
I have a big master plan in operation that i will start a thread about once i get it all underway