What size copper pipe to use to bypass manifold?

[Guest Anonymous]

What size copper pipe do i need to make a bypass pipe?

I plan to go from the water pump to a short hose to the copper pipe to the heater hose.

I'm trying to get everything together before I disassemble the intake to replace the downdraft carb and i figured it would be just as good as the official 320i or 2002ti bypass pipe. right?

Thanks,

Mike

'76

[Guest Anonymous]

Ooo...

I think the secret is to use copper pipe, and solder a union on each end. I seem to remember that the water pump works best with a 3/4" union (about 7/8" od) and the heater was a 1/2", at a bit over 5/8" od. But don't take this as gospel!

.

So you'd need a transition from 1/2 to 3/4 somewhere in there.

And do make some sort of retaining bulge (I made an even bead of solder) at the ends, 'cause after a while, the hose clamps can slip. HTH,

Toby

[Guest Anonymous]

Assuming that I could find fittings (metal or plastic) to adapt the larger hose to the smaller hose, could i just run rubber hose instead of copper pipe?

[Guest Anonymous]

Got a 1" heater hose to fit the pump and a small section of pipe to join it to the heater hose. I think they may be different sizes for different years.