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Dan Scully
11 posters

General Cooling Questions


Number of posts : 193
Location : Upstate South Carolina
Age : 56
Registration date : 2012-06-20

General Cooling Questions - Page 3 Empty Re: General Cooling Questions

Post by lws67 Tue Jan 15, 2019 3:04 am

The water pump is a Gates brand (many brands available, likely the same part in different packaging), I forget the part number, but it has 8 vanes (impeller) vs. 6 vane. Nothing fancy or special, its cheap. Theres much confusion about 6 and 8 vanes, and theories about moving water through the system too slow or too fast and time for the coolant to draw the heat etc etc. Many are adamant on the theory the coolant needs time to absorb heat. Theres too much misinformation. Just run an 8 vane. Move the coolant faster. Just search for a lengthy thread about cooling problems by a member named Busman? He had a cooling issue with rising temps. He replaced everything to no avail, assumed his new hipo 6 vane pump was good. His last attempt was replacing it with an 8 vane and problem solved. I'm running billet alloy pulleys, but they are OEM diameter.

Number of posts : 54
Location : San Francisco, CA
Registration date : 2016-01-18

General Cooling Questions - Page 3 Empty Re: General Cooling Questions

Post by Brandon2 Tue Jan 15, 2019 11:33 pm

As I mentioned, the only time I have problems cooling is long runs over steep grades.  Otherwise I'm fine -- so I doubt my water pump is causing any issues.  I've also heard people talk about FlowKooler water pumps making a difference.  I was curious what other people had seen.

I have seen water flow being important, because at one point I replaced a Stant Thermostat with a RobertShaw high flow, and could easily tell the difference in cooling performance.

According to the parts book, 69-71 D100 318 engines with AC used 3004763, which has 6-vanes.  All A100's (which did not ship stock with AC) and D100 318 engines without AC used 3004762, which has 8-vanes.

This page has some detailed info:

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