Remote Radiator and epw

So I had this idea for how it would be possible to have a rear mounted radiator and waterpump with  no restrictive thermostat and still regulate temperature Whlie always keeping full flow between the pump and engine. I posted it up on another sight hoping to bounce some ideas back and forth but all I got was "this guy did this"... Anyways...

I've been planning a rear radiator in my c6 for a while now to make more room under the hood, improve cooling and weight distribution. The plan is to have the radiator and ewp mounted in the back with 2 hoses running to a engine water manifold but the problem with that setup is controlling coolant temperature while adding little to no flow restriction. I've seen setups that have a thermostat with a small bypass but that seems far less than ideal. Since the pump would be in the back you would want full flow between the pump and engine at all times while being able to control water flow through the radiator. After looking and reading these last few days I think I came up with something. forgive the crude drawing

Hot coolant comes into a tee where it has 2 2"solenoid valves one going through the radiator and the other going to another tee that connects to the radiator outlet and ewp inlet. The solenoids could be controlled by a simple thermostatic switch and 5 pin relay. The valves are oversized compared to the pipe in the system due to the restriction they would cause if they were the same size as the pipe at 1.25" Here's the solenoids I'd like to use https://ussolid.com/2-solenoid-valve...iton-seal.html
Its a bit overly complex for a problem that might be solvable with a remote thermostat but I like to overthink things.

What do yall think?

I don't have lots of experience with remote radiators in cars but lots of UTV (side x side) experience. I think your plan is pretty good. The only thing I would possibly change is to move the valves to the cool side of the radiator. The reason is the lower temperature the may increase lifespan / reliability of the valves.

Not a bad idea! I was also thinking about a small bypass 1/4-3/8 to the radiator to "equalize" the temperature a bit to there's less of a shock to the system when it switches over

I would us normally open (NO) valves, especially on the radiator loop. That would ensure that in the event of a valve failure there will still be coolant flow through the radiator. The ones you picked are normally closed (NC), so a loss of power or failure would shut off flow. 

Whenever I've brought it up, on my COE truck, before forums were a thing and we talked in person, I was told

"The water pump won't be able to move the water that far"

um, did you miss the part where the only parts of the lines that were longer were horizontal?

and water seeks is own level?

Then they'd just start making up stuff, to keep their point!

Never did move things around on that truck, so I'm no help, but interested in following this!

The 'NO' valves are a good point. 

In reply to 03Panther :

Friction loss is a thing. Maybe not enough to stop it from working, but I would run some napkin calcs before assuming everything is good to go. 

In reply to spandak :

I did not finish my EE degree, before switching to my Apprenticeship. The Journeyman Outside Machinist included most of a two year degree, but those classes were a really long time ago... and more than a few brain cells!

Definitely get the (assumed fairly minor) friction losses, but don't know how to start those calcs. 
If I ever make those changes to the 'ol COE (doubtful) I'll definitely reach out. 
For now I'm just excited for th OPs project!

Thanks 

All right the components are on the opposite ends here, but these uses standard  Chevy water pumps, no EWP and no thermostat, just a slight flow restriction. McRae F5000 and McLaren M8F, which cools an aluminum 840BHP "Chevy". With road racing speeds both these cars have trouble free cooling systems right up to the frontal impact. Almost any EWP should equal that performance level with little strain until the system length grows a whole lot longer than a car, or radiator vertical location becomes problematic. The pump's potential head pressure should be a published number. That gives you all you need regarding vertical position. 

Here on our forum, GoGators has an auto cross C5Kart with a rear mount radiator, check his build out too. 

Nebraska ... you're overthinking it, nothing wrong with that. My suggestion is go ahead and do it with basic coolant tubing and fittings (no valves, wiring nor thermostats) then experiment with those. Use a temp sensor to switch the pup/fan when the heads are half warmed up so no thermal shock.

I have a first gen Camaro, 350 mild cam daily driver, has had radiator under the trunk for 4 years and 10k miles.

Fabricated coolant log manifold in 1.5" x 16g al tubing that replaces the SBC waterpump, 90^ radiator hose bend down to al tubing past the steering box then follows chassis rail over axle to factory brass radiator with relocated inlet/outlets. Passenger side returns over axle to DaviesCraig EWP 150 under the rear seat void. Out of there towards the propshaft and along past trans, fabbed a heat exchanger using in-radiator GM type trans cooler element inside a 2" brass tube, then up beside headers to intake manifold thermostat housing WITH NO THERMOSTAT.

All al tube sections are grounded to prevent galvanic corrosion.

Some bends are rubber OE type 1.5" bends to provide flex. Underbody brackets are rubber flex mounts so no stress in tubing.

Note, I have sidepipes from front wheels to rear wheels. With undercar exhaust there would not be enough space to package the al tubing .

DaviesCraig electronic fan controller switches radiator fan at preset temp (110*) at cyl head. Then 10 sec later switches the EWP.

So ... the coolant system is totally open, no valves, no thermostats. Coolant warms up in similar time to OE. You can cover the grill opening with 1/8" clear polycarb sheet for fuel economy.

Our climate here in Melbourne Australia is temperate, similar to Northern CA. Mid 50s in winter to 80s in summer. Low humidity.

HOWEVER ... airflow in my application is restricted by lower than stock ride height, and the fact that I didn't want to cut ducting into bodywork. 

Raised trunk floor approx 4" is still barely enough to package the radiator and electric fan (2.5" is thinnest I can source), the fan is pulling air from above radiator and blowing towards the ground. The crossflow radiator is in the original gas tank space, mostly horizontal but tilted down 3" at front and tight to floor at rear edge. I have al ducting attached to the rear axle tubes to deflect air upward then sealed to a floor-mounted shroud with surprisingly effective sliding seals. Fabbed al framework holds radiator and looks like a diffuser from the side/rear. 

From LOTS of experimentation (I have 7 digital temp gauges and 3 cameras in the car), airflow under the car is ok up to 80 kph (50 freedom units) but after that it is too turbulent to flow up behind the axle and into the ducting. Driveable for 45 minutes before it heat-soaks. Tire squirt also a factor, screwing the pooch. Bumper-to-bumper traffic really needs those rubber flaps in a fan shroud, but my situation cannot have a shroud cos I need airflow, and rubber flaps don't work laying down.

DO NOT RELY ON AL TUBING TO DISSIPATE HEAT ON THE RUN FROM THE ENGINE TO THE RADIATOR ... IT WILL NOT!

NEVER use an electric fan in front of the radiator. Efficiency takes a dive. 

As a result, my car is not driveable at ambient temps over 90*. (coincidentally, having aluminum interior, no carpet, no a/c, my body doesn't WANT to drive over 90* so no downside effectively).

Would I do it again??? Only if I had more/better incoming airflow, maybe stand the radiator up in a rear mount installation.

Probably HAVE to go with side inlet ducting similar current Corvette, and shrouded outlet ducts exiting between taillamps low pressure zone.

Reason I did it??

- Covid lockdown boredom, I had raised the trunk floor for this project when I built the car 20 years ago. 48/52 weight distrubution with driver and half tank fuel. Noticeable on turn-in and speed humps, even at suburban speeds.

- Because RACECAR.

Jim Grant

Way Cool!! Thanks for the pictures. Explains a lot.

In reply to OzRaceFan :

That's a very cool setup. I hope you have better luck with the Davies Craig controller than a friend of mine, his has taken a dump twice, and because the controller died, there were no alarms.