Heater Core Tubing Size

Goat_guy · Post by **Goat_guy** » Wed May 12, 2004 3:22 pm

On the common heater core list, I have been looking at 2-274 (FEDCO, 399026 GDI), and noticed that the IN and OUT is listed as .625" (5\8"). Does this mean that it will fit 5\8"OD tubing (1\2"ID)? Would there actually be barbs, or would there just be inserts for the tubing, where really strong hose clamps would be needed?

1911user · Post by **1911user** » Wed May 12, 2004 4:45 pm

The 5/8 tubing size listed for the heatercore tubes is an OD meaning outside diameter of 5/8 inch. 1/2 ID tubing can fit over 5/8 OD fittings but it has to be streched. Heating it with hot water helps soften the tubing and makes streching it over the tube easier. This is one place that thick wall tubing is handy. It can be pushed and twisted much harder without collapsing. You could buy a pre-modded (barbed) heatercore especially for watercooling.

5/8 ID tubing should fit easily over the heatercore tubes. They don't come with typical barbs, just 2 copper tubes soldered into the heatercore.

You also want to use hoseclamps (I prefer metal) no matter how tight or loose the tubing fits onto the barb. Leaks are expensive, hose clamps are cheap; don't even think about not using them IMO

chylld · Post by **chylld** » Wed May 12, 2004 8:27 pm

yep as 1911user said, 5/8" refers to the outer diameter of the barb, which corresponds to the inner diameter of the tubing. clearflex/tygon dipped in hot water for a few seconds should go over it fine.

and NEVER skimp on hoseclamps. ALWAYS use hoseclamps no matter how tight you think you have it.

Gooserider · Post by **Gooserider** » Thu May 13, 2004 9:33 am

Also, on many HC's, especially the ones with lengthy plumbing coming out of them, the actual pipe coming out of the tanks is only 1/2" OD. Just the last inch or so of the pipe will be flared out to the nominal diameter listed on the spec charts. If you cut off that flared out bit then you have the 1/2" OD to work with.

This leaves you with just a straight pipe to fit the hose over with no barbs to catch it, but clamping will help with this. Another thing that I like to do is gently work on the end of the pipe with a tapered punch or equivalent so that the end flares out a very small amount (Just enough to feel). This makes the tubing a little harder to get on, but will act as a mini barb to keep the hose from sliding off once you put a clamp on it.

Gooserider