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Old 06-17-2015, 11:36 AM   #1
happyhunky
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high flow water pump

I am in the process of finishing up my 57 4x4 project. I'm having trouble keeping the temp down below 230 degrees. I have a mild 350, headers, performer intake, edelbrock 1406 carb backed by a frame mounted cooler th350. My radiator is a new champion aluminum 3 core with a 2500 cfs pulling electric fan with full shroud. I'm in the process of continually flushing the system till it's totally clean. And I checked the 160 degree thermostat to make sure its working at opening at 160 and it does start to open and fully opens by 180. Maybe someone can help here. I'm thinking my only other solution is to go to a high flow water pump. The reason thinking is that my body is on a shortend 1976 suburban frame. So the lift is body not suspension. Hence it is roughly 14 inches vertical that the water has to get back into the radiator. Being a pressurized system does that lift matter for a stock water pump, or would I see a difference in a high flow pump. Thanks for your input and knowledge.
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Old 06-17-2015, 12:16 PM   #2
OrrieG
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Re: high flow water pump

Is your gauge accurate? Get a probe type temp gauge and bring the engine up to the high temp but not boiling. pull the cap and check the temp against the gauge. I had the same thing going on with my Chevelle, over a month it started running hot. Turned out the 15 YO gauge had decided to start reading 10-15 degrees high. You said the t-stat starts to open an 160 and is fully open at 180, seems like it should open faster. You might try a 180 thermostat. I would also look at the fan shroud configuration. A small fan with a relatively flat shroud only pulls air in the area in front of the fan. I kept my radiator in the six cylinder location and used a deep shroud (see pic). Before I took it off the road my 59 4wd (74 drive train on 59 frame) ran around 200 in town, 180 on the road, some times saw 220 or so off road crawling on logging roads. It was 283 w RV cam, th350, np203 transfer with Nash part time conversion. This build I upgraded to a big truck radiator because I plan on towing a small travel trailer.
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Old 06-17-2015, 12:30 PM   #3
happyhunky
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Re: high flow water pump

Thanks OrrieG. Here's a pic of my fan shroud setup. It's a 16" fan. I can put my hand in front of the radiator and feel air being sucked through most everywhere. Not real sure of the gauge. I have new electric autometer gauge but using the sending from the other aftermarket gauge. Wasn't sure of the brand. Will check with thermo.
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Old 06-17-2015, 05:33 PM   #4
Speedbumpauto
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Re: high flow water pump

"I have new electric autometer gauge but using the sending from the other aftermarket gauge" Big No No! Get the correct sender for the gauge.
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Old 06-18-2015, 12:34 AM   #5
twinsemi
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Re: high flow water pump

How about the pulleys? Underdrive pulleys (to put more power to the wheels) result in less flow than you might want. Normal WP pulley is about 3/4 the diameter of the crank pulley. The hi flow pump can get that back for you. I don't think the height difference will make much difference since the water is a closed loop circuit. Harder to push up to the top means the radiator outlet is also higher and helps push it back in to the pump.
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Old 06-18-2015, 06:57 AM   #6
happyhunky
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Re: high flow water pump

Thanks for all the help guys. It is the sending unit. Using a probe thermometer in the radiator shows 180, where truck gauge shows 215.
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Old 06-18-2015, 12:03 PM   #7
OrrieG
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Re: high flow water pump

Easy fix, that is always the first thing I check, learned it from my millwright Father who spent a lot of time arguing with pipe fitters for pressure and temperatures at the paper mill. Need to also make sure the probe stays calibrated, I had one start reading off that was causing problems too.
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Old 06-18-2015, 02:42 PM   #8
mr48chev
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Re: high flow water pump

I ran into the same issue on my buddy's roadster 35 years ago. His gauge was reading 265 but he could (scary thought) pull the radiator cap off and it didn't blow steam or puke coolant. With a probe off the Snap-On truck the Walker Radiator rep at the car show we were at showed him that the temp was actually hovering just above the rating of the thermostat. Name brand electric gauge. Good to see that you got it fixed.
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