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

[charliew]

Geoff isn't the stock suby about 1.250? I thought thats what I measured on the suby radiator I have. Since it's a longer run than the stock application I would use 1.250 on both sides. What size are the inlets and outlets on the radiator you are going to use?

[budman5201]

i have used larger sizes and had cooling problems. When i just went with Renegades sizes, no matter which Subaru engine i have done. ej25 n/A 165 hp, ej20 Turbo 300 hp, or ez30R 250 hp N/A.... Never had problems.

Think it has to do with smaller forces the water to the radiator and larger makes it an easier path back to the engine.

I am running Marine grade reinforced hoses exactly the same sizes as Renegades and bought renegades reducers to/from the engine to make them fit the subaru engine. (obviously this was a LONG time before i knew how to weld aluminum. Today i would of just made them myself.

[strawman]

i have used larger sizes and had cooling problems. When i just went with Renegades sizes, no matter which Subaru engine i have done. ej25 n/A 165 hp, ej20 Turbo 300 hp, or ez30R 250 hp N/A.... Never had problems.

Think it has to do with smaller forces the water to the radiator and larger makes it an easier path back to the engine.

I am running Marine grade reinforced hoses exactly the same sizes as Renegades and bought renegades reducers to/from the engine to make them fit the subaru engine. (obviously this was a LONG time before i knew how to weld aluminum. Today i would of just made them myself.

Thanks Budman; great info! (IMG:style_emoticons/default/beerchug.gif)

Are you using "hardwall" wire-reinforced hose or polyester-reinforced hose?

My Suby EJ22T has 1-1/4" outlet (top of engine) and 1-1/2" inlet (water pump). My Griffin 25241 radiator has a 1-1/2" inlet (upper hose) and a 1-3/4" outlet. Looks like I need to buy or weld up some adaptors! (IMG:style_emoticons/default/welder.gif)

[computers4kids]

Hi Geoff!
If you go to your local truck shop, you will find the gate green stripped hose and clamps and a decent price by the foot. Your shell is looking pretty sweet it's nice to watch someone else grinding and scraping for a change with a cold beer in my hand. LOL

All I can say about the Renegade cooling setup is "it works" and very well...even in hotter than hell Visalia. I wouldn't mess too much with success in that area.

Mark

[strawman]

Thanks Mark for the tip about truck parts suppliers... there are a few in nearby West Sacramento. Enjoy the beer and the relatively mild summer we're having here in the Central Valley!

Geoff

[Britain Smith]

Why is it not a good idea to run aluminum pipe? I was planning on running thru the interior, passenger side as running under the car is not an option for ground clearance.

-Britain

[v82go]

Hi

I have been using aluminum conduit for several years (without problems), it seems to dissipate heat alot better than the rubber hose it replaced. On the other hand, I am only cooling 350 horses in a little v8.

Bob

[Britain Smith]

Any pictures of your set-up?

-Britain

[strawman]

Why is it not a good idea to run aluminum pipe? I was planning on running thru the interior, passenger side as running under the car is not an option for ground clearance.

-Britain

Hi Britain --

My understanding is that metal pipes could burst if scraped over speedbumps, etc., whereas rubber hose will "give" -- up to a certain point. But since your car is a trailered autox monster, you wouldn't have to worry about that. I'm also not a big fan of coolant hoses running inside the cab of a car, but since yours is not a street car and the pipes wouldn't be "soft," you're probably fine. I suppose it might be wise to check the sanctioning body (SCCA? PCA?) to see if they address that issue, though...

Geoff

[Britain Smith]

Ok, since we are on the subject. What radiator do you recommend? Size?

This will be paired up to a Subaru 2.5L Turbo engine for AX applications only. I want to run a very compact, efficient radiator. Any suggestions.

-Britain

[strawman]

Ok, since we are on the subject. What radiator do you recommend? Size?

This will be paired up to a Subaru 2.5L Turbo engine for AX applications only. I want to run a very compact, efficient radiator. Any suggestions.

-Britain

Our engines are different; I'm using a stock EJ22T engine with OEM ECU, but with a larger TD05-16G turbo, slightly larger injectors & a fuel cut defenser setup. I also plan to use a manual spring-ball boost controller -- at least at first (electronic unit to follow, unless my cheap ass finds one sooner!). It should put out ~190hp at ~10psi, according to the "experts" on the LegacyCentral website. I'll use my car as a spirited canyon carver and occasional AX toy, so I need the car to handle hot summers here in the Sacramento Valley.

I have adapted a Griffin aluminum radiator into my tub; specs found at:

http://www.summitracing.com/parts/GRI-1-25241-X/

I bought this radiator off of Craigslist, and it is rated for up to 400hp as shown in http://www.griffinrad.com/race_radiators.cfm. If you're really going to pump up the boost on your engine, you might need some additional cooling capacity... but since you're only using it for short AX runs, you might just go for a "Scirocco" drag racing radiator. Those can be found cheap at Summit, JEGS, etc.

I am also using a huge 4600cfm radiator fan out of a Lincoln Continental Mark VII. It is used by a lot of the rockcrawling 4x4 crowd, since it is lightweight and cheap (bought mine for ~$30 at a local Pick-n-Pull). See my build blog for pics on how I setup the shroud and radiator mounting. Again, you'll probably need a much smaller fan & shroud to cool the system between runs.

Caveat Emptor: mine is not yet running, so this is all theory!

[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

[D Cope]

Granger has bulk silicone heater hose 100 ft sections 1/2 $107 5/8 $118 3/4 $126

The best price so far

David

[Britain Smith]

Ok, back on this subject.

Lets discuss options of running the water lines that do not involve going under the car.

-Britain

[BRAVE_HELIOS]

I took the local 914-v8 guys suggestion and built steel rectangular cooling tubes... 1" x 2" x (0.120" walls... overkill I know) that run under the car. They have had no issues with setup... I hope I don't either!!

[BRAVE_HELIOS]

Ok, since we are on the subject. What radiator do you recommend? Size?

This will be paired up to a Subaru 2.5L Turbo engine for AX applications only. I want to run a very compact, efficient radiator. Any suggestions.

-Britain

Our engines are different; I'm using a stock EJ22T engine with OEM ECU, but with a larger TD05-16G turbo, slightly larger injectors & a fuel cut defenser setup. I also plan to use a manual spring-ball boost controller -- at least at first (electronic unit to follow, unless my cheap ass finds one sooner!). It should put out ~190hp at ~10psi, according to the "experts" on the LegacyCentral website. I'll use my car as a spirited canyon carver and occasional AX toy, so I need the car to handle hot summers here in the Sacramento Valley.

I have adapted a Griffin aluminum radiator into my tub; specs found at:

http://www.summitracing.com/parts/GRI-1-25241-X/

I bought this radiator off of Craigslist, and it is rated for up to 400hp as shown in http://www.griffinrad.com/race_radiators.cfm. If you're really going to pump up the boost on your engine, you might need some additional cooling capacity... but since you're only using it for short AX runs, you might just go for a "Scirocco" drag racing radiator. Those can be found cheap at Summit, JEGS, etc.

I am also using a huge 4600cfm radiator fan out of a Lincoln Continental Mark VII. It is used by a lot of the rockcrawling 4x4 crowd, since it is lightweight and cheap (bought mine for ~$30 at a local Pick-n-Pull). See my build blog for pics on how I setup the shroud and radiator mounting. Again, you'll probably need a much smaller fan & shroud to cool the system between runs.

Caveat Emptor: mine is not yet running, so this is all theory!

Thanks for the heads up on the fan! I just purchased the same radiator... although it is the -H model which has the filler neck deleted. Any issues mounting the fan? Did you use a thermo switch with your setup... from the same Lincoln? (IMG:style_emoticons/default/smile.gif)