Material choice for coolant tubes

[Ken H]

Hi Folks,

I'm getting ready to fabricate new underbody coolant pipes on my hotrod project Scorpion. I'll also be replacing the heater pipes that run inside the center tunnel. I want these to last a while so corrosion resistance is a concern.

I'm considering both stainless steel (easier to weld) and aluminum (lighter, cheaper). Any comments or suggestions, anyone?

- Ken

[cthargiss]

Ken, .032 wall stainless is almost as light as .080 wall aluminium, and while almost twice as expensive, it can be bent by any muffler shop so no welding required. SS can also be beaded by most race shops and unlike aluminum, will not corrode. So if your budget allows, and you do not need to shave ounces for racing, go with the stainless. Thin wall stainlesss is available from Tube Supply, Tube Specialties, and Aircraft Spruce, also Columbia Airmotive has some. Craig

[Wallace]

Done mine in stainless. A bit thicker than I'd like (18 guage ) but the only stuff that was readily available. I used 1 /12 inch "off the shelf" bends to join the straight bits - and to make the hose barbs on the end which I silver soldered on. 35mm tube with just about fit nicely into 1 /1/2 inch 16 guage pip -allowing for a bit of movement to get everything lined up ok.

The main problem with the bends were the two that go up from under the car to the back bulkhead. It's a "bastard" angle (127 degrees ??) and rather than blow cash and get something bent up, I just removed a segment from a 135 degree bend, closed it up to the right angle and welded it back up again ! A bit of polishing/grinding and you can't see the join !

I darsay a good exhust fabricator could bend something up a bit lighter and neater - but my radiator is bigger than standard so the stock pipes couldn't just be copied. Ands I didn't fancy towing the car anywhere to have the pipes made up to fit !

One thing I would recomend is a couple of collars on the near verticle pipes on the back bulkhead positioned just above the locking clamps to keep the pipes in the right place without tightening them up too much !

[Ken H]

Guys,

Looks like stainless is the way to go. We have many sources here in the US: Burns, SPD Exhaust as well as aircraft supply companies such as Wicks or Aircraft Spruce. I'll compare the cost of pre-bent vs having the local shop do the bends. Thanks for the advice!

- Ken