The best location for an electric water pump SBC V8 conversion, The best location for an electric water pump SBC V8 conversion Options

[914GT]

Here's the timing mark setup on my engine. The orange mark on the balancer is at TDC and 0 degrees on the timing pointer. It would be nice to have it lower but I can still easily see it from under the car.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i216.photobucket.com-2923-1493172655.1.jpg)

[BRAVE_HELIOS]

Just a couple of things.

Electric pumps flow less coolant than a mechanical water pump at nearly everything above idle, if you're having a cooling issue installing an electric pump is going backwards. The reasons to install an electric pump are if you need to remotely mount a water pump or you're trying to get the absolute most horsepower you can out of an engine. If you think the water pump is the issue, get a Stewart high flow water pump and be done with it knowing you've got the best on there and it's not a WP issue.

More flow=more cooling, it's physics. You don't want to slow down your flow, a restriction will only cause problems, not help them.

If you're having problems, I'd first make sure what I had is working correctly. It sounds like you're having issues, or at least worried about bleeding the system. When I was building my V8 Volvo, I had similar issues which took out a headgasket before I bought an Airview coolant refill kit, and eventually ditched my convoluted setup. It uses shop air to create a vacuum and then sucks the coolant back in leaving it perfectly filled without air voids. Looks like there are cheaper ones out there like this. Yeah, it's a bit of money, but it's worth it -- it makes my life so much easier on dozens of cars (but not my bugs or 914).

I don't know the history of your engine, but if you're sure that you don't have any mechanical issues (such as head gasket, or timing) that could cause it to run hot, I'd reconsider the size of my radiator and the airflow through it.

I looked at the Airview system:

https://www.ecstuning.com/b-schwaben-parts/...ol/003466sch01/

Wouldn't my vacuum brake bleed tool work the same? When connected; it uses vacuum from a compressor to draw out coolant from the radiator petcock and as long as I keep the overflow bottle full; I can continue bleeding the system like this until (I feel?) the system has been successfully bled.

[BRAVE_HELIOS]

Here's the timing mark setup on my engine. The orange mark on the balancer is at TDC and 0 degrees on the timing pointer. It would be nice to have it lower but I can still easily see it from under the car.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i216.photobucket.com-2923-1493172655.1.jpg)

Awesome! But it looks like the engine has to come out in order for me to do this... that's a lot of work :-)!

[914GT]

Right, one of those things that would be done with the engine out. If you need to drop the engine to take care of other issues then adding a relocated timing mark would be something to add to the list.

[burton73]

Just wondering. The picture of your SBC with a Dedenbear WH-1 got me curious.
I went to their site and saw that they had Electric water pumps set to flow 23 GPM.
The other pumps that where covered in posting pumped much more that that. Question is a slower GPM flow better for cooling. I think it has been posted many years ago but I cannot remember. Also where do you get a Vibration Dampener for a HP SBC with a V belt grove? I have a very old one from GM in the 60s.

Bob B

[914GT]

The Dedenbear remote pump on my conversion has performed very well for the past 15 years so I don't feel that GPM numbers are extremely critical. Obviously you need enough coolant flow to prevent excessive coolant temperatures where it exits the engine and hot spots inside the engine. But that's also going to be dependent on the engine inlet temperature (and radiator performance). The more important factors are going to be radiator size and efficiency, and controlled air flow through the radiator. The pump is moving the heat from the engine to the radiator, the actual heat exchange is from the radiator to the air. That is where more flow is better (air flow) and not really the coolant flow rate from engine to radiator. There are a lot of arguments over this, not just in the 914 conversion world, and that's fine. But I know the setup I have works well for me.

Another thing that needs to be considered is that even though a pump can flow a maximum GPM under ideal or no-load conditions it won't necessarily be able to flow that rate in an real closed cooling system. The engine block, heads, thermostat, pipes/hoses and radiator will all restrict flow and trying to force a higher GPM through the system can result in excessive pressures or turbulence. It would be nice to know if there's an optimum GPM for a system but that's probably unique for every situation. If you had a flow meter with temperature & pressure gauges you could probably get some numbers to take some of the mystery out of this.

On the V-groove balancer that is a GM part, p/n 3896590. As far as I know it's still available from GM and other sources online.

[dwillouby]

Glad I saw this! I am going to order this pump as I currently have the Renagade setup.
Mine seems to cool fine but the engine heat soaks when shut down. I want the use the electric pump to run after the engine stops and circulate till temps come down.
I was going to try the Davies Craig pump but have to rework things. I will sell this pump(new in box) to buy the other.

David

[BIGKAT_83]

Glad I saw this! I am going to order this pump as I currently have the Renagade setup.
Mine seems to cool fine but the engine heat soaks when shut down. I want the use the electric pump to run after the engine stops and circulate till temps come down.
I was going to try the Davies Craig pump but have to rework things. I will sell this pump(new in box) to buy the other.

David

This will answer a few questions about which cools better belt driven or electric. Interested to see if you see any difference in the cooling when running. I'm thinking of going with a electric pump just to free up space to mount a ac compressor.


Bob

[burton73]

Thanks for the lead on Davies Craig pump I looked them up on the web.
It sure looks trick. Davies Craig DC-8870
The EWP 130 is made of aluminum with AN fittings. Not sure what model would work best for SBC and 914 layouts but I guess this is it. $465. For the kit with controller. Another $114. For the SBC set up on the engine. Davies Craig DC-0444 - Davies Craig Digital Thermatic Fan Switch Kits . $77. More

Not sure if that is it but the full boat is looks like it would be like it is $656. Not cheap but if it works perfect?



Bob B

[dwillouby]

Ordered the Jegs pump today.
Will see what happens.

To help with the new pump I will sell the Davies Craig pump and parts I have.

New never ran.
200.00

[Andyrew]

I highly recommend the LCD controller for the davies craig pump. I LOVE mine.

The water pump runs on its pulse setting pretty much the entire time because its so efficient. It actually rarely gets up to temp doing that. Which I guess I should have guessed since I bought the v8 pump for my 1.8T..

[BRAVE_HELIOS]

Ordered the Jegs pump today.
Will see what happens.

To help with the new pump I will sell the Davies Craig pump and parts I have.

New never ran.
200.00

So why are you going from this pump to the Jegs unit? Depending on what you say... I may be interested in your Davies pump!

[dwillouby]

Basically It will be less reworking of my system and cost.
I already have the Renagade pump and the hoses connected.
With the Davies pump I will need to change the hose arrangement and add a Dedenbear water log, fittings ect.

I may regret selling the davies system but who knows?
David

[BRAVE_HELIOS]

Basically It will be less reworking of my system and cost.
I already have the Renagade pump and the hoses connected.
With the Davies pump I will need to change the hose arrangement and add a Dedenbear water log, fittings ect.

I may regret selling the davies system but who knows?
David

I understand... I would be in the same situation. Well, let me know how it goes with the Jegs unit because I might very well be the next test case for the same!

[BRAVE_HELIOS]

An update... Today, I had a chance to drive the car after removing the Prestone flushing fluid and bleeding the system the best I could. I drove for around 3 miles before the temp crept up past 200. This is with the temp controller set for the fan to come on at 180. Ambient air temp was around 72 degrees and I got it up to 70 as a short burst and around 50 most of the rest of the way. This trek was actually better than before where 3 miles would have been a miracle. Was it all the flushing? I have read that a good flushing takes a long time and with many attempts. IDK but obviously, this is still not enough.

When I did get it home, the temp was around 200. I shut it down and opened the trunk where I noticed the overflow tank was full and in a matter of a few moments, water started coming out of the overflow hose of the tank and onto the ground. Mind you when I started the trip, the overflow tank had water in it (that was post bleeding and idling in the garage for a long period of time). I went back to the car after 20 minutes or so and the system had sucked ALL the water from the overflow tank back in... and probably sucked in air at that point too.

I did notice something though... now the car can sit idling in the garage for an hour or longer and never go past 180. It's not until I take it for a drive will the temperature increase.

Did I not read somewhere that when this occurs, it is relatively clear that it is more a function of a defect in air flow through the rad and/or how the hot air expels from the front trunk area and not from deficient water pump flow?

I am trying to come up with the next logical part of the system to address.

[BRAVE_HELIOS]

Any one have insight to the running hot when driving versus at idle issue... please :-) .

[914GT]

If you're spilling out that much coolant it would seem to me that your system isn't holding pressure. Did you check by pressuring the system (cold) using compressed air and a gauge to see what point your radiator cap opens?

When you're driving the engine is under load and is going to generate more heat. So holding correct pressure (15-17 psi static) is going to be an important factor. Possibly there is some kind of turbulence in the radiator air flow while in motion. I suppose you could see what difference it makes driving around with your hood off as an experiment. I kind of doubt this is the problem though. My guess there's still a pressure problem or maybe still trapped air in the radiator or above the intake manifold somewhere.

[BRAVE_HELIOS]

If you're spilling out that much coolant it would seem to me that your system isn't holding pressure. Did you check by pressuring the system (cold) using compressed air and a gauge to see what point your radiator cap opens?

When you're driving the engine is under load and is going to generate more heat. So holding correct pressure (15-17 psi static) is going to be an important factor. Possibly there is some kind of turbulence in the radiator air flow while in motion. I suppose you could see what difference it makes driving around with your hood off as an experiment. I kind of doubt this is the problem though. My guess there's still a pressure problem or maybe still trapped air in the radiator or above the intake manifold somewhere.

You know; the expansion (header) tank is from a VW Passat I got from the breakers yard. It looked in good nick but just in case, I replaced the cap with a new one. Perhaps the tank really is hosed. Any recommendation on the type of tank I should look for?

[914GT]

The most common is probably one similar to this. The small fitting fits a hose going to your overflow tank.
(IMG:http://www.rickwrench.com/images-sounds/filler.jpg)

Renegade makes one that looks nice. This would have to connect into your system with a tee and be mounted high in the engine bay.
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.renegadehybrids.com-2923-1493926666.1.jpg)

I use a modified Dedenbear tank that bolts onto the intake manifold over the thermostat. It has a lot of volume but it can be a little awkward to fill. I just use a long funnel and it's something I only need to do every few years.

Are you sure the cap on your Passat tank is a pressure cap and not simply a fill cap? Is there a pressure rating on it? Having never seen one I don't know anything about that.

Edit: Here's a used Dedenbear tank with an AN fitting. This one is on ebay for $75. These tanks have a section of clear nylon tubing so you can visually check the coolant level in the system. Mine had that but the tubing discolored after a few years and I plugged the holes. To clear the firewall on mine I cut off the hose connection and tapped the hole to thread in a 90 deg fitting.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i216.photobucket.com-2923-1493927705.1.jpg)

[burton73]

The most common is probably one similar to this. The small fitting fits a hose going to your overflow tank.
(IMG:http://www.rickwrench.com/images-sounds/filler.jpg)

Renegade makes one that looks nice. This would have to connect into your system with a tee and be mounted high in the engine bay.
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.renegadehybrids.com-2923-1493926666.1.jpg)

I use a modified Dedenbear tank that bolts onto the intake manifold over the thermostat. It has a lot of volume but it can be a little awkward to fill. I just use a long funnel and it's something I only need to do every few years.

Are you sure the cap on your Passat tank is a pressure cap and not simply a fill cap? Is there a pressure rating on it? Having never seen one I don't know anything about that.

Edit: Here's a used Dedenbear tank with an AN fitting. This one is on ebay for $75. These tanks have a section of clear nylon tubing so you can visually check the coolant level in the system. Mine had that but the tubing discolored after a few years and I plugged the holes. To clear the firewall on mine I cut off the hose connection and tapped the hole to thread in a 90 deg fitting.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i216.photobucket.com-2923-1493927705.1.jpg)

Why would there be a quick connect air fitting on the Dedenbear tank overflow tube? Good-looking parts.

Bob B