Remote Water Pump - Flow Theory.

[Emc209i]

Look like I'll be doing some revamp work on a SBC Fiero within the month. The owner wants to replace the CSR 901R with a remote mount electric pump, so the 901R doesn't have to be taken off to drop the cradle and to also clean up the engine compartment - although the 901R is leap and bounds a better solution than V8Archie's butchery of wheelwell pulleys. He's been communicating with FieroGuru, who has been very kind in counseling him and explaining things. I was going to just email him, but I thought it wouldn't harm anything to post it here and get a discussion going.

So it looks like we would use this adapter bar. It's thin, and I can bring the coolant feed in from either side, perfect. Only thing I'd need to do then would to be run a remote pump. While this is straightforward enough, I do have some concerns. Placement is one - I understand the pump can be placed just about anywhere, but lower is better to prevent cavitation and help prime. But ideally, should it be pre-thermostat opposed to post? Does it matter? I imagine the heater core circuit is the primary bypass while the thermostat is closed, and prevents the pump from burning up when the stat's closed. Does the SBC have an internal bypass, or strictly the heater core? These are the questions bouncing around in my head. I went through my library of manuals and race car dynamic handbooks, and there's little to nothing about this - probably do to publication dates (need newer books).

With my understanding thus far, this is what I want to do. Place the remote water pump at the front of the car right behind the radiator inlet. There's a heater core feed already coming out of the intake manifold - keep it, should work well. Tee the heater core return into the left coolant pipe under the car (suction side). Is this a sound plan of action? This car may not even have a thermostat, I need to check.

Diagram:


Oh.. and Shaun, technical opinions welcome, but keep the SBC drama out of it. Thanks Brah.

[fieroguru]

You will want to install the water pump on the radiator outlet on the passenger side, the heater core return needs to be plumbed into the pump (or in the hose between the radiator and the pump. The heater core outlet from the engine "should" be as close to the thermostat housing (plumbed under the thermostat) as possible to ensure adequate flow of heated coolant to activate the thermostat.

The SBC had a separate coolant bypass (additional hole in the block and water pump on the passenger side (RWD configuration), but in pretty much every SBC/Fiero installation this bypass is blocked off and the heater core circuit remains the only bypass (so you must plumb in the heater core, or at least a loop.

The water manifold might need to be modified slightly to clear the frame rail on the rear inlet and to clear the belt on the front side.

[Emc209i]

Exactly what I needed to know, thank you!

[Nashco]

For a slightly different perspective, I'm just about to go with a remote electric water pump on one of my projects...a Chevy 4.3 into an old VW Bug. I had an OEM pump on it, but in an effort to reduce the package space and weight for the engine, I'm going remote. I just received this pump and controller kit:

http://www.daviescraig.com.au/Electric_ ... tails.aspx

I thought about getting the Dedenbear water manifold, but I'm a little turned off about paying $100 for such a simple casting. Don't get me wrong, it's a great plug-and-chug part, but I think it will be more fun and nicer looking to make one from tube steel myself, I'm weird like that. My car doesn't have a heater core, and I'm not sure if I will ever add one. If I do add one, I'll probably use a small electric pump (like the Bosch intercooler/heater booster ones) and run it in parallel to the engine pump.

IMO, you've got your pump on the wrong side. Your pump should always pull from the radiator outlet, that way as long as there is SOME coolant in the radiator, it will pull cool fluid and push it through to the engine. The way your diagram above shows, if the engine outlet has air in it (boiling, head gasket, etc.) then your pump will stop moving fluid. By pulling it from the radiator outlet, you give that air a chance to separate and pull just fluid. With my setup, I'm not running a thermostat at all. The pump controller adjust pump flow based on coolant temp, so the thermostat becomes unnecessary, which makes life MUCH easier on the pump and reduces electrical power consumption.

In summary, by not running a heater core with my initial install, things are a little different, but it's something to think about. At the very least, I highly recommend you change your plans for the pump location in the system.

Bryce

PS...just saw Fieroguru said what I said, pretty much...except with less words. Oh well.

[Emc209i]

PS...just saw Fieroguru said what I said, pretty much...except with less words. Oh well.

You provided reasoning why the pump should be used at the outlet, and for that I'm greatful - you answered the "why" I came away with after reading Guru's post last night. I learned something, thanks for explaining.

I agree that the bypass is rather pricey for a cast aluminum piece. The reason we're considering it is for packaging reasons. With the cast bypass installed, I expect the face of it will scrape the frame rail when I reinstall the V8. There really isn't ANY room for fabrication - kind of at that point where a raised weld on something I built would defeat the purpose using the bypass; so the drivetrain clears the frame.

I'm very familiar with the pump and fan controller, I spent several weeks last month researching the DCC controller extensively - I'm contemplating using it in conjunction with a meziere on my turbo 3800 so that I can use a tiny belt from crank to alt. The Davies Craig unit looks nice also, I'll do my homework on it, thanks.

Link to the Delta Current Control unit. - Link

I will revise the diagram later tonight. I'll move the pump post radiator, and have the heater core return before the pump and after the radiator. The heater core feed that's being used now works really well, so I'll continue using that feed. Excellent!

[The Dark Side of Will]

I didn't see a 90R1 listed on the CSR site.

I'll echo what's been said so far... put the waterpump someplace in the right side coolant tube.

What year FIero is it? The '85 (and I think '86) V6's brought the heater circuit return right into the waterpump. The '87 and '88 V6's T'd the heater core return into the right side coolant pump from the factory.

I'd be concerned about running the pump based on thermostatic electronic control. Some amount of circulation is NECESSARY to make sure the engine warms up evenly. That's one reason modern engines have recirculating thermostats--the water that doesn't go to the radiator goes right back into the engine--instead of the simple "stop valve" thermostat that SBC's have.

If you do decide to use electronic control on the pump, be aware that where the sensor is placed will significantly affect how quickly it warms up when the engine starts. Is this engine carbeuretted? How many other temperature switches are there?

[Nashco]

If you do decide to use electronic control on the pump, be aware that where the sensor is placed will significantly affect how quickly it warms up when the engine starts.

Give the thermostat-avoiders some credit Will! Here's the control strategy on the pump (see page 8):

http://www.daviescraig.com.au/Images/Ca ... 202010.pdf

Obviously, common sense says you need to be sure your coolant temp sensor goes somewhere that gets a reliable measurement.

Bryce

[fieroguru]

There really isn't ANY room for fabrication - kind of at that point where a raised weld on something I built would defeat the purpose using the bypass; so the drivetrain clears the frame.

I respectfully disagree...

At the rear most water pump inlet (as installed in the fiero), you should have 1 3/4" of clearance between the block and framerail at the water pump bolts... give or take a little depending on engine placement side to side and front to rear. This is plenty of room for fabricated solutions and if you route the hoses right, you could rock the cradle back to change the belt (or remove the valve covers).

Back in 2002 or 2003, I fabricated a coolant manifold from bent pipe to wrap around the top side of the timing cover (similar to the one above, only with a single inlet)... specifically designed to allow engine removal without removal of the coolant manifold. I never used it since I ditched electric pumps and went custom mechanical.

This fabricated piece from my mechanical setup cleared the frame rail just fine:



Others have used AN fittings (modified slightly to pull them in tighter to the block).

This area of the SBC swap is very, very tight and needs to be well though out to allow proper function, fitment and servicing.

[The Dark Side of Will]

If you do decide to use electronic control on the pump, be aware that where the sensor is placed will significantly affect how quickly it warms up when the engine starts.

Give the thermostat-avoiders some credit Will! Here's the control strategy on the pump (see page :

http://www.daviescraig.com.au/Images/Ca ... 202010.pdf

Obviously, common sense says you need to be sure your coolant temp sensor goes somewhere that gets a reliable measurement.

Bryce

'80's GM cars use about 12 different locations for temp sensing, gauge senders, fan switches, etc...


As far as the available space... there's room for a conventional waterpump turned upside down, so there certainly ought to be room for the Dedenbear water log.

[The Dark Side of Will]

This area of the SBC swap is very, very tight and needs to be well though out to allow proper function, fitment and servicing.

LOL... you've seen a Northstar in place, right?

[Emc209i]

I didn't see a 90R1 listed on the CSR site.
What year FIero is it? The '85 (and I think '86) V6's brought the heater circuit return right into the waterpump. The '87 and '88 V6's T'd the heater core return into the right side coolant pump from the factory.

Is this engine carbeuretted? How many other temperature switches are there?

I mistyped it, it's a 901R. http://www.summitracing.com/parts/CSI-901R/

I've worked with the heater routing on all model Fiero's. The car is an '86, but the routing at firewall appears to have been changed completely already. The routing has been re-engineered at least twice, so nothing remains of the stock routing. I've got the heater core figured out, if we decide to use it. The owner has expressed he cares very little for heat because the car will be parked in the cold - which would be ideal if we yanked the thermostat anyway.

The car is currently carbed but will be converted to EFI sometime in the near future - I believe courtesy of FieroGuru. I imagine there's either one switch for the fan currently, or it's hotwired on. I think the electronic unit is much better thought out than you're giving it credit. I'll send you - here.

I respectfully disagree...

Fair enough. The owner is reading this thread and has high regard for your opinion, so I'll leave that to him. I don't have access to the machining capabilities you do, and so I think the cast unit will serve our needs best at this point, but again entirely up to him.

This area of the SBC swap is very, very tight and needs to be well though out to allow proper function, fitment and servicing.

I couldn't agree more, and right now, it's very very very poorly thought out. With a compact bypass, front mounted pump, and replumbing lines, the car will be 300% better both in look and function.

Here's what I'm working with.

[The Dark Side of Will]

The owner has expressed he cares very little for heat because the car will be parked in the cold

Personally, I'd remind him that it really sucks to have a foggy windshield and no defroster.

The car is currently carbed but will be converted to EFI sometime in the near future - I believe courtesy of BMWGuru.

Umm... have you read this thread? http://www.fiero.com/forum/Forum3/HTML/0 ... .html#p267

I think the electronic unit is much better thought out than you're giving it credit. I'll send you - here.

That's a fan controller, not a pump controller... but here are some gems:

The coolant entering your engine is now at about fifty degrees Fahrenheit

I find that *EXTREMELY* hard to believe. Water has a VERY high specific heat. A single pass through a radiator in 30 degree air will *NOT* bring it from 195 down to 50, which is what the article asserts.

you've just temperature cycled your engine some 140 degrees over the span of about 30 seconds

The metal in the engine has an additional heat capacity such that this just won't happen. AND the engine is making its own heat...

Given that your radiator cycles from + 14 psi to -3 psi each and every time that your fan cycles on and off

Complete bullshit.

If that article's a good example, maybe I'm *over*estimating the design insight of electronic controllers.

[fieroguru]

The car is currently carbed but will be converted to EFI sometime in the near future - I believe courtesy of BMWGuru.

I believe it is coming to my place for the EFI upgrade once I get done reworking another SBC/Getrag swap.

I am with Will on the controller... total waste of $$$ and will do more harm than good. They are street rated pumps and have been used with thermostats w/o issue... just make sure you have the bypass (which is the heater core circuit) plumbed correctly.

[Nashco]

'80's GM cars use about 12 different locations for temp sensing, gauge senders, fan switches, etc...

What's your point? Also, did you see the link I posted about the Davies Craig water pump control strategy? I figured you would acknowledge it isn't as ghetto as you imagined...

Bryce

[The Dark Side of Will]

'80's GM cars use about 12 different locations for temp sensing, gauge senders, fan switches, etc...

What's your point? Also, did you see the link I posted about the Davies Craig water pump control strategy? I figured you would acknowledge it isn't as ghetto as you imagined...

Bryce

I did take a gander at it and it does look reasonably robust and well thought out. The only thing I wasn't aware of was the circulation when cold.

My point was that there are lots of different sensor locations that may read different temperatures. Fan switch in the block, gauge sender in the head, CTS next to the thermostat housing... Which one gets replaced with the sensor for the EWP?

[Emc209i]

-Lunch break-

Thank you all for your input, I appreciate it. First thing I want to clear up, BMWGuru is not involved and hopefully NEVER will be. I was in a hurry last night and I always get the two confused, but it's FieroGuru who will be getting the car later on - like he said above. Will I've read that thread and many others, I wouldn't send my lawnmower there.

We've got a little bit of time to think everything through while I finish painting. Sounds like using the controller may involve more risk than the stat, I believe the system works well the way it is now, so maybe it would just be the wisest thing to just move the pump location and be done with it. Lots to think about.

There is no pump controller currently, it's ignition on powered.

[Nashco]

'80's GM cars use about 12 different locations for temp sensing, gauge senders, fan switches, etc...

What's your point? Also, did you see the link I posted about the Davies Craig water pump control strategy? I figured you would acknowledge it isn't as ghetto as you imagined...

Bryce

I did take a gander at it and it does look reasonably robust and well thought out. The only thing I wasn't aware of was the circulation when cold.

My point was that there are lots of different sensor locations that may read different temperatures. Fan switch in the block, gauge sender in the head, CTS next to the thermostat housing... Which one gets replaced with the sensor for the EWP?

In my experience, the one where the coolant temp sensor for the ECM is tends to be the most reliable (almost always next to the thermostat) and is what I plan to use for my project. None of them are useful if they're in air, so that is a factor if your sensor is close to the top of your system and you don't have a low coolant level sensor. As I said, common sense stuff...none of us are going to ruin an engine if the temp sensor is inaccurate by 10°F if everything else is working properly. This isn't rocket science.

The only hole I see in the Davies Craig control is if you start running the piss out of the engine when it is still (truly) cold, and the pump doesn't circulate for many seconds. However, if you do that, you kind of deserve what the results are.

Bryce

[Emc209i]

I find that *EXTREMELY* hard to believe. Water has a VERY high specific heat. A single pass through a radiator in 30 degree air will *NOT* bring it from 195 down to 50, which is what the article asserts.

The metal in the engine has an additional heat capacity such that this just won't happen. AND the engine is making its own heat...

Complete bullshit.

If that article's a good example, maybe I'm *over*estimating the design insight of electronic controllers.

Thank you for pointing these things out Will.