914 engine conversion: water-cooled hose specs, Engine-to-radiator and water-air intercooler hoses Options

[strawman]

I've searched but can't seem to find definitive answers about what size and specs for the coolant hoses for my turbo Subaru engined conversion. I'm interested in real world experience from others that have running water-cooled conversions. Based on my research of this site, I've decided to follow most conversion guys' use of rubber hoses in lieu of SS or aluminum pipes for the long run between the engine and radiator -- run in the recesses along the bottom of the chassis.

Renegade Hybrids sells Gates Green Stripe (or equivalent) hose, in 11' of 1-1/4" ID and 13' of 1" ID for -- including clamps -- for $100. According to their website, they recommend 1-1/4" I.D. from lower radiator to pump and 1" I.D. from upper radiator to the thermostat housing. Those sizes provided by Renegade would require that I use adaptors for both ends on each hose(engine and radiator), so I've searched the usual suspects like Ebay, NAPA, Rock Auto and marine suppliers for bulk heavy-duty 1-1/2" ID hoses -- but my head is spinning from all the options.

Is a "hardwall" rubber hose required (the type with wire reinforcement) for the engine-radiator hose? If so, marine exhaust hose seems to sell for ~$5.00 to $8.00 per foot on Ebay. It seems like the suction side should be beefier so that it doesn't collapse when hot, but maybe that is not important, so a two-ply polyester-reinforced hose might suffice. Any opinions from you Chevy V8, Subaru or other guys?

I'm also looking for 25' of 3/4" ID heater hose for my water-air intercooler setup, as my heat exchanger is mounted in front of the radiator. Again, is hardwall rubber hose required, or would any high-quality two-ply polyester-reinforced hose work?

Thanks for your opinions!

Geoff

[stewteral]

I've searched but can't seem to find definitive answers about what size and specs for the coolant hoses for my turbo Subaru engined conversion. I'm interested in real world experience from others that have running water-cooled conversions. Based on my research of this site, I've decided to follow most conversion guys' use of rubber hoses in lieu of SS or aluminum pipes for the long run between the engine and radiator -- run in the recesses along the bottom of the chassis.

Renegade Hybrids sells Gates Green Stripe (or equivalent) hose, in 11' of 1-1/4" ID and 13' of 1" ID for -- including clamps -- for $100. According to their website, they recommend 1-1/4" I.D. from lower radiator to pump and 1" I.D. from upper radiator to the thermostat housing. Those sizes provided by Renegade would require that I use adaptors for both ends on each hose(engine and radiator), so I've searched the usual suspects like Ebay, NAPA, Rock Auto and marine suppliers for bulk heavy-duty 1-1/2" ID hoses -- but my head is spinning from all the options.

Is a "hardwall" rubber hose required (the type with wire reinforcement) for the engine-radiator hose? If so, marine exhaust hose seems to sell for ~$5.00 to $8.00 per foot on Ebay. It seems like the suction side should be beefier so that it doesn't collapse when hot, but maybe that is not important, so a two-ply polyester-reinforced hose might suffice. Any opinions from you Chevy V8, Subaru or other guys?

I'm also looking for 25' of 3/4" ID heater hose for my water-air intercooler setup, as my heat exchanger is mounted in front of the radiator. Again, is hardwall rubber hose required, or would any high-quality two-ply polyester-reinforced hose work?

Thanks for your opinions!

Geoff

Hey Geoff,

The first conversion car I drove had hard galvanized pipes running under the car and they scraped for a foot of length getting out of the parking lot. From that moment, I was convinced having ANY type of water hose or pipes under the car was a risky idea.

On my car, I cut open the top of the shift tunnel (and found a lot of rust to clean out) and ran 1-1/2" copper water line from the engine bay to the front trunk.
I did some checking and found that there is room to run the tubing UNDER the fuel tank and into the front trunk. It's not a straight shot, but I found (2) 45-degree bends made it work. With copper, I assembled the pieces and then "sweat-soldered" it all together in-place. The tubing has worked flawlessly for 8 years.
I took care to place sections of PVC pipe under and around the tubing to protect from chafing and closed the top of the shift tunnel with a sheet of aluminum. While the tunnel is warm, some insulation should cut the temps to hardly noticeable.

If all the above to just too much work for you, at least look at tucking the water lines under the rocker panels so they will be safe from damage.

Hope this helps,
Terry