Landracing Forum
Tech Information => Technical Discussion => Topic started by: ronnieroadster on April 22, 2015, 07:53:21 PM
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Been wondering about the amount of gallons per minute flow for 12 volt electric water pumps I looked at various Mezier pumps and find lows of 20 to high of 55 GPM The electric pumps I use are Jabsco centrifical low preasure the advertised flow rate is 29.7 GPM at 8.7 PSI. I use two of these pumps on my flathead one per side my water tank has a capacity of 18 gallons. I use a radiater cap that holds zero preasure no preasure build up saves the tank from expansion {found that out the hard way} no side spliting etc. So far I have not had any issues with these pump flow rates but Im always wondering.
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I have a PRP 55 gallon pump that I use as a pump on Ms. Liberty and it actually flows around 20 pushing from the back of the car to the front radiator in a tank. sorry I haven't put a pressure sensor on it yet.
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All pumps are rated free flow without restriction. 12 volt electric water for racing are not very powerfull and 55gpm free flow is about the limit.
20gpm thru a engine block and radiator/tank is not bad for a 55gpm pump. I think in most most LSR application a 55gpm would be a minimum.
Also Electric water pump do not create alot of pump pressure, you would be lucky to see around 5-6 psi if you dead head most of them. Pump Pressure is important in high horse power and boosted application.
Most electric pump only draw around 8-12 amps.
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Thanks for the quidance guys I will do an actual flow rate for the pumps using the water tank in the car looks like Im going to get wet. I will post the results my hopes are the two pumps combined will get to the 20 GPM rate. :cheers:
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Looking forward to it, Ronnie. Wayno
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My eng. uses a conventional belt driven pump. The eng. needs the PRESSURE as well as the volume.
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From the archives...for what it may be worth. Attached worksheet has a graph of test results of various pumps. Object of the exercise was to choose a pump for intercooler circulation. Since the Mezier and CSI pumps were “on hand”, the model numbers weren’t recorded. (As I recall, the Mezier was blue). Also don’t recall what the “inlet restriction” was, but was probably a short suction hose. The “twin Jabsco” was two of the more common brass Jabsco’s connected in series. The stainless Jabsco was borrowed and reputed to be much “better” than the ordinary ones. The curves for the Jabsco’s with part numbers were plotted using published data.
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I think the belt driven pump that we use from Stewart is rated at 160 GPM. It is supposed to use minimum hp to run, but we were running it at nearly engine speed and it was breaking the v belts. We cut it back to half speed of the engine and the belts are happy now. No sign of overheat. There is no free ride as the electric pumps also put a load on the alternator or draw the battery down at the expense of the ignition. The trick would be to run an electric pump and cover the car with flexible solar cells. [Hmmmmmm].
Doug :cheers: :cheers: :cheers:
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IO;
That spread sheet looks blank- no data. Is it just me?
Regards, Neil Tucson, AZ
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Make sure you're at the upper left hand corner of the sheet Neil. Mine loaded where the graphs didn't show and I had to go up the sheet.
Pete
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Ronnie, I have used just about every brand of 12v pump on the market and found the Meziere to be the best by far. All of my fittings are chamfered for flow and I use a 1-1/4" line to feed the pump an a -16 line to the GMC 6. The engine has 2 returns the stock one from the front of the head is a -12 and a -10 from rear top of the head. The system is not pressurized but I guarantee there IS pressure in the engine by limiting the flow back to the tank. Maybe not a lot but pressure all the same. The 55 Meziere really helped with this. There is a Stewart 12v electric that fits in the feed line to a stock belt pump that really adds pressure but the electronics that run it are really sensitive to heat. Good luck..JD
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Just completed flow testing the Jabsco pump. The readings I took were threw the block using the 3/4 inch lines in the car. Pump flow per side is 11.11 gallons per minute. Im sure the low flow rate is being caused by the size of the head gasket holes in the 8BA block. Adding to a further reduction in flow the upper water holes in the deck are not open I was trying something different on this combination cant say that modification worked as I was trying to support the block from cracking issues which did not help.
When I get an unmodifed block in the car Im sure the flow rate will go up. But for now at this flow rate theres no heating issues BUT im only running the mile for now.
Thanks to everyone for their imput great information I find theirs always more to learn.
Ron :cheers:
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Neil, the graph should be there somewhere, as noted earlier by Peter Jack. There was no “data” included because I just lifted the graph from within a big, complicated worksheet with a lot of extraneous other information.
Since posting it, I perused some Jabsco information on the internet. Jabsco seems to have hundreds of pumps, not just these little electric ones. The bronze “twin Jabsco’s” appear to have been models 18510-0000 and 18510-0010, which seem to have been the bottom of the line 12v pumps, which, it turns out, even at the time were discontinued. Their replacement appears to be the “stainless” pump.
It is interesting that the deadheaded performance of the twin arrangement is roughly the sum of the two pressures from the published information, but that the flow rates at low pumping pressures don’t begin to compare to that published. When citing pump info, use of the actual model numbers and operating conditions are essential to avoid confusion.
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Make sure you're at the upper left hand corner of the sheet Neil. Mine loaded where the graphs didn't show and I had to go up the sheet.
Pete
Thanks, Pete. I see the overlaid graph sheet but there are no graph lines on it. The problem must be on my end; I'm using Open Office to view it but I haven't seen any problem like this before.... oh well.
Regards, Neil Tucson, AZ
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Conducted a different test today on the flow rate of the Jabsco 50840-0012 Marine High Flow Stainless Cyclone Pumps I use on my engine. With the pump just pumping water from the tank the pump flows 15 gallons a minute the feed and discharge hose diameter is once again 3/4 inch. Still well below the advertised 29.7 GPM.
In my previous test threw the block the flow rate was 11.11 GPM. Doubling that figure for the two pumps flow rate combined is 22.22 GPM.
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Lingenfelter's test results on electric pumps .
http://www.caddyinfo.com/cadillacs/Intercooler%20pump%20flow%20vs%20pressure%20drop%20graph%20WM%20with%20pump%20curve%20estimate.jpg