Fiero coolant system with 3.4l DOHC and EWP

[Aaron]

Well I have been talking to Steven a bit about this, and we are kinda split on how I should run the system. Will if you could jump in that'd be great.

Now my EWP has a controller that makes it a thermostat. It regulates voltage between 4v and 14.5v. When I first start the car, before warmup, it runs at 4v to circulate a small amount of coolant. Once it hits a temperature than I determine, it starts regulating its voltage to keep it at that temperature.

My problem is this. D-C, maker of this EWP, says to remove the thermostat. But if I do this, even at 4v it will take forever to get the car warmed up. Even though coolant flow is minimal, the Fiero's capacity is huge, and it'd be constantly running the water through the radiator. I don't want this. But if I leave the thermostat in, there is the possibility of the water pump turning on, and increasing voltage, when the T-stat is closed. This will cause problems.

So I'm thinking the best route would be to get a 160 or 180* thermostat, and set the water pump to turn on at 200* or so. So once the car gets to 180*, the T-stat opens, and I have minimal flow, 4v worth. But then it hits 200, and the water pump increases voltage, and keeps the water at 200. Thus the T-stat would be open all of the time, except on cold starts, where its only purpose would be to get the car to warm up quickly.

When the T-stat is closed, the engine will still get coolant flow through the heater core and the TB line.

What do you all think?

[The Dark Side of Will]

It's good to have circulation through the engine during warm up to help prevent hot spots from building up and keep the internal temps consistent.

What you might try is plumbing the pump to push water through the engine and have the heater core loop come back into the circuit *upstream* of the pump, so that with the thermostat closed, the pump is still circulating through the heater circuit. That would be the best of both worlds.

[Shaun41178(2)]

you could drill some holes in teh thermostat allowing some coolant to bypass it at all times. its an old hotrodders trick actually to help keep the engine cooler and to allow it to flow more coolant.

[Aaron]

It's good to have circulation through the engine during warm up to help prevent hot spots from building up and keep the internal temps consistent.

What you might try is plumbing the pump to push water through the engine and have the heater core loop come back into the circuit *upstream* of the pump, so that with the thermostat closed, the pump is still circulating through the heater circuit. That would be the best of both worlds.

Yah this is already planned for. It will not only have the heater core line, of which the inlet is before the T-stat, but I also have the throttle body line if I need more flow at cold start. So it will flow, I think 4v through those lines will be enough. The pump will be placed in like the factory location, so it is downstream of the heater core return line and the TB bypass line.

My main concern is whether to use a T-stat or not. Steven says I should, because if not, even at 4v it will take forever to warm up because there is simply so much coolant.

I think the best option is to use one, but get a 160* one. Then at 160 it opens, and the motor gradually increases to wherever my pump is set at, let's say 180 or 200 for now. Then once there, the water pump controls it. I think this would work great, but hopefully it won't hurt the T-stat to be open nearly 95% of the time.

There is also one more concern. My pump can be set up to keep flowing after engine shut down, and I want to take full advantage of this. But doing so, the T-stat would close after shut down. So my only flow would be water through the block, with none of it goign through the radiator. So the cool down would be VERY gradual. Plus, I think it'd hurt the pump if it was running at 14.5v and the T-stat is closed. Maybe there's a way, or it does so automatically, to only run it at 4v after shut fown.

[The Dark Side of Will]

As the temp drops, the controller will reduce the voltage to the pump...

[Shaun41178(2)]

Iam telling you, drill some small holes in the thermo if you are worried about it even after shutdown. then the pump can still circulate coolant after it shuts off and the thermo closes.

[Aaron]

As the temp drops, the controller will reduce the voltage to the pump...

I'm not sure if it does this or not. I think it might use one steady voltage after shut down. But at any rate, will it be bad for any part of the system for the pump to run at 14.5v, max flow, with the T-stat closed?

Iam telling you, drill some small holes in the thermo if you are worried about it even after shutdown. then the pump can still circulate coolant after it shuts off and the thermo closes.

But Shaun you're missing the point. If I wanted flow, I'd take the T-stat out altogether. But if I take it out, or drill holes in it, it will cause the car to take a lot longer to warm up, and I DEFINATELY don't want that, not in CO. I don't anticipate problems cooling the motor, this is in an effort to get it up to temperature faster, wilst minimalizing negative effects. And while the flow block is a negative effect, the pump will still have no problem cooling the engine.

[Shaun41178(2)]

Drilling a few small holes will take it longer to heat up as if no holes were there, but a few small holes dont' equal one big hole with the thermo is completley out now does it?

[Aaron]

Drilling a few small holes will take it longer to heat up as if no holes were there, but a few small holes dont' equal one big hole with the thermo is completley out now does it?

No it doesn't. But the ENTIRE purpose of the T-stat being in there in my application is to make it warm up as quickly as possible. That is its only function.

Well I was talking to Steven, and the T-stats restriction came up. So I started thinking, and if it will be an issue, why do I need a T-stat since my EWP is controlling temperature? I DON'T. All I need is a valve. So I think if I plumb in a 1-2" valve, acuated by an electric switch, it'd work. Just close it on every cold start, then open it when you near 160*, then just close it on the next cold start. Perfect. Less of a restriction when warmed up, more reliable, and stays open after shutoff.

So now I need to find a 12v DC valve that can handle 200* water...

[emod19]

Don't turn the pump on until the engine warms up.

Steve

[Aaron]

Don't turn the pump on until the engine warms up.

Steve

But then you don't have any flow, and it develops hot spots as Will said. You need some flow, and for quick warming, you need this flow to bypass the radiator. If you notice, most every stock system is setup up like mine will be. So all I'm doing is adding the EWP essentially in the same place as a typical pump.

As for the valve, I found it. http://www.jeffersonvalves.com/index.asp. They will have exactly what I need for sure, I'm going to call them tomorrow. I sure hope they don't cost much and don't weigh too much, but it will be so worth it.

[Aaron]

Alright I think the valve I need is here:

http://www.jeffersonvalves.com/valvesmodels/1342.asp

Normally open, 1.5" connections, 3.1kg, good up to 150*C with Ethyl-propylene, which is about 300*F, more than enough for my purpose. I'll also need it to be weather-proof.

I am going to call them sometime this week and figure out the exact piece I need, and what it will cost me. I'd like it to be no more than $50, but this is a pretty important piece. It will extend the life of my water pump, and my engine.

[The Dark Side of Will]

As the temp drops, the controller will reduce the voltage to the pump...

I'm not sure if it does this or not. I think it might use one steady voltage after shut down. But at any rate, will it be bad for any part of the system for the pump to run at 14.5v, max flow, with the T-stat closed?

What leads does the pump controller have? In order to behave differently after shutdown, the controller would have to know when the engine's running. It also wouldn't make any sense for it to be stuck on max flow after the engine's turned off.
Occam's razor says that it acts the same after shutdown as it does when the engine's running.

It's a centrifugal pump, right? Pushing against a closed thermostat will increase the pressure difference across the pump, which *might* cause cavitation depending on the design of the wheel and a few other things. I'd say it's pretty safe to run it against a closed thermostat. See what the people who make it have to say. Also, ask them how long their test engines take to warm up relative to operation with a thermostat.

Power = Voltage[sup]2[/sup]/R
So going from 4V to 14V increases power by 192/16 = 12. I think that flow is proportional to the square of power (somebody check this...), so flow will increase linearly with applied voltage.

[eHoward]

We ran our FSAE car with one of those pumps WITHOUT the thermostat.

My problem is this. D-C, maker of this EWP, says to remove the thermostat.

[Aaron]

What leads does the pump controller have? In order to behave differently after shutdown, the controller would have to know when the engine's running. It also wouldn't make any sense for it to be stuck on max flow after the engine's turned off.
Occam's razor says that it acts the same after shutdown as it does when the engine's running.

It's a centrifugal pump, right? Pushing against a closed thermostat will increase the pressure difference across the pump, which *might* cause cavitation depending on the design of the wheel and a few other things. I'd say it's pretty safe to run it against a closed thermostat. See what the people who make it have to say. Also, ask them how long their test engines take to warm up relative to operation with a thermostat.

Power = Voltage[sup]2[/sup]/R
So going from 4V to 14V increases power by 192/16 = 12. I think that flow is proportional to the square of power (somebody check this...), so flow will increase linearly with applied voltage.

I did a bit more research, and you were right, it performs the same after shutdown. Meaning it'd run at 4v the majority of the time, right after shutdown until it hits a set temperature I decide, or after a certain amount of time. But even at 4v, I'd like to have the T-stat open to cool it down quicker.

It is a centrifugal. I doubt it'd have a problem against a closed thermostat, especially with my 2 bypasses. The people who make it don't really have applications, the most I find is a lot of different vehicles with it adapted. I have yet to find one that talks about warmup time, but I'll look into it. Also, if I use the above valve, I could test it to see how long it takes to warm up by leaving the valve open and warming it up with the pump flowing 4v.

We ran our FSAE car with one of those pumps WITHOUT the thermostat.

That's interesting, it is even more critical on bike motors to warm them up before hard operation, and I've never been on one with a regulated redline. But again, the FSAE car's coolant system is dramatically smaller than the Fiero's, and the engine theoretically makes just as much heat.

[p8ntman442]

aaron, look at the Kv coefficeint of that valve, and then ask yourself what does that mean. Its pretty high, and you may not be gaining much by removing the thermostat. I think shaun is right, you should just drill some holes in the thermostat, or weld on a small diameter bypass tube.

[Aaron]

aaron, look at the Kv coefficeint of that valve, and then ask yourself what does that mean. Its pretty high, and you may not be gaining much by removing the thermostat. I think shaun is right, you should just drill some holes in the thermostat, or weld on a small diameter bypass tube.

Have you read this thread at all?

I don't want to drill holes in my T-stat. Then it will take longer to warm up. And on a motor that I plan to push to the limits that already has known bearing problems, the faster the oil gets warm the better.

And if you'd read, you'd know I already have 2 quite large bypass lines (5/8"). What pisses me off is when people reply without first reading the thread.

[Kohburn]

don't use a thermostat then. use a solenoid valve combined with a lew temp fan switch.. rather than turning on a fan it will open the valve after the car is warm

best would be a 2 way valve so that cold it directs the flow through the bypass and warm it put it to the radiator

but you are using an electric pump.. so why have bypasses or a thermostat valve at all - why not just turn the pump on once the engine reaches operating temp?

[donk_316]

Sounds like your over complicating and over analyzing something that seems so obvious. Dont worry about this at all. Go with the recommendation from the manufacturer. As in : use your ewp and no thermostat. Honestly what is 5 min longer in warm up time? Who really gives a shit.

[Aaron]

don't use a thermostat then. use a solenoid valve combined with a lew temp fan switch.. rather than turning on a fan it will open the valve after the car is warm

best would be a 2 way valve so that cold it directs the flow through the bypass and warm it put it to the radiator

but you are using an electric pump.. so why have bypasses or a thermostat valve at all - why not just turn the pump on once the engine reaches operating temp?

A 3-way valve would be cool, but the factory bypasses are more than enough. The valve I showed above is exactly that, a solonoid valve. But instead of a thermal switch, I'd have an in-cab switch.

I could do that, but then there is no way to regulate temperature. The pump also HAS to operate even when cold or the motor will develop hot spots.

Sounds like your over complicating and over analyzing something that seems so obvious. Dont worry about this at all. Go with the recommendation from the manufacturer. As in : use your ewp and no thermostat. Honestly what is 5 min longer in warm up time? Who really gives a shit.

The engine already has bearing issues as it is. I'm not going to get out of my driveway, and drive like a gramma for 20 minutes. If I can have it warm in 10 and ready to waste a Mustang, I'd like that. This will allow the engine to last longer, as I predict my engine failure to eventually be bearings.