I need to fabricate a section of my engine to radiator return line out of metal. I’m thinking exhaust tubing or EMT electrical conduit. The EMT is light, weldable, easy to bend (because I know an electrician with the bending dies).
Stupid idea or OK?
GO!
If you run an anti-freeze, I think it should be fine. The anti-freeze should minimize corrosion.
I've done copper pipe and exhaust pipe in engine swaps.
Copper is almost as esy to bend and you can form a lip on the end to help hold the hose on. That being said, I have used straight pieces of copper pipe without a lip.
Why not?
Engines are full of bare iron and steel exposed to the cooling system after all.
Knurled. said:Why not?
Engines are full of bare iron and steel exposed to the cooling system after all.
but the metal is thicker than conduit. I would see if you can get some SS tubing
Just a thought- most of the EMT I've installed has a coating applied to the ID to make it easier to pull wire through it.
No clue what the stuff is, or how it would stand up to temperature, liquids etc. It may be worth researching a bit though. I'd hate to read about it flaking off and clogging an artery in they system.
mad_machine said:Knurled. said:Why not?
Engines are full of bare iron and steel exposed to the cooling system after all.
but the metal is thicker than conduit. I would see if you can get some SS tubing
Not really... a lot of water pump impellers are 16 gauge or thinner. And how thick are radiator and heater core tubes?
I usually use exhaust pipe when I have to make a hose adaptor.
never seen a steel radiator or heater core.
Friend of mine put a chrome thermostat housing on his impala. In less than a year it had to be replaced due to rotting through. Unlike the waterpump impeller, the conduit/pipe is only exposed to liquid on one side, the outside is still exposed to the elements and can rust. I still say SS or copper, just make sure both are well supported as they do work harden and crack over time
In reply to mad_machine :
I've seen lots of aluminum radiators and heater cores, and aluminum is a far more corrosion-prone material than steel, and they seem to last well enough.
Chromed aluminum sucks for corrosion for some reason beyond my metallurgical expertise.
Use steel, paint the outside, use coolant on the inside, all will be well, move on with your life.
Spitfires use a plain steel pipe to route coolant from the water pump to the heater plumbing on the flywheel.
They usually last 20-30 years before pinholing through. Stainless replacements are preferred.
Meanwhile, freeze plugs are plain steel, no one questions that (though maybe they should).
As for exterior rust, every EMT conduit I've ever seen is plated.
I say DO IT !!!
I ran 1.5" aluminum tube from the engine to the radiator in the back of the BatVan. Hindsight tells me I should have knurled or somehow peckered up the end the rubber hose clamped to; it let go dramatically when someone was inside.
I ran EMT conduit to my front mounted radiator on the fiat. When I disassembled it 7 years later it was spotless inside. I would have no qualms doing it again.
Go for it.
I have used pre-bent exhaust tubing before. It will rust eventually, but I never cared.
Thanks for the various thoughts and ideas - it's always interesting how diverse even the most mundane items can become. After my OP - I started to realize that the bend radius for 1.5" EMT was going to be too large (after all they want to be able to pull wire through it). So I've ordered up a section of pre-bent exhaust tubing from Summit.
Thanks everyone!
EMT is coated in zinc so no, it is not weldable. Not safely at least. Even if you put the effort to clean the ends, fine traces wil make the weld pourous which seems counterproductive if you're moving coolant. Also, welding it will produce extremely toxic gasses. Not worth the risk dollar for dollar. You can hop on ebay and find pre bent tubing for this application. Look up 1-1/2" (or whatever diameter you are using) SWAN bend tubing. The swan bend gives you a 180 degree bend, a 90 and a 45. You can then cut it up and create whatever you want. Below is a picture of my supply line for my rear mounted radiator setup.
mad_machine said:never seen a steel radiator or heater core.
Friend of mine put a chrome thermostat housing on his impala. In less than a year it had to be replaced due to rotting through. Unlike the waterpump impeller, the conduit/pipe is only exposed to liquid on one side, the outside is still exposed to the elements and can rust. I still say SS or copper, just make sure both are well supported as they do work harden and crack over time
What are the odds that housing was made of chrome plated zinc?
XJ Jeeps used a steel section of pipe coming out of the water pump.
I know you solved the problem, just adding data.
Blasfamous_1jz said:EMT is coated in zinc so no, it is not weldable. Not safely at least. Even if you put the effort to clean the ends, fine traces wil make the weld pourous which seems counterproductive if you're moving coolant. Also, welding it will produce extremely toxic gasses.
I came to say this. EMT is galvanized. Welding it is not wise.
I've used pipe made for sink drains. It's made of brass and usually chrome plated and has some very tight bends. It's made in 1.25 and 1.50 inch sizes. There may be others if you search around. The pipe will accept a solder bead at the end to hold a rubber connecting hose in place.
914Driver said:I ran 1.5" aluminum tube from the engine to the radiator in the back of the BatVan. Hindsight tells me I should have knurled or somehow peckered up the end the rubber hose clamped to
Trivia: When I signed up, the username "Peckered Up" was taken.
In reply to Blasfamous_1jz :
Zinc plating (aka Galvanize)? Nothing a quick dip into Pool Acid won't take care of, just about 1" on the tip will do the trick.
Flush with water, weld away ....
Or, just gas braze it.
(Always wear eye and skin protection)
In reply to clshore :
Or wire brush it as good as possible and hold your breath while welding, and don't inhale until you're far away.
Teh RX-7's harness bar is galvanized water pipe, and I used to use that stuff to make suspension links because cheap. I have one link that I sliced and butt welded about five times while trying to get the pinion angle right and it never came apart.
Now, gate material on the other hand... yeesh! I had to fix a gate latch that broke at a weld. It was galvanized after welding (obviously) and I wire wheeled everything. I jigged it up, hit it with the MIG, and after I released the trigger (shutting off the flow of argon) a huge JET of green flame blew out of where I was welding. I'm no expert and not much of a never-was-pert but oddly colored flames I know to stay the hell away from... I opened the doors and turned on the ventilation fans to get the smoke out of the building.
I never had anything like that happen from welding water pipe!
Galvanized stuff can definitely be welded. Just clean it up as best as possible first and make sure to have good ventilation and generally take precautions to avoid breathing the fumes (they can make you very sick).
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