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What's a high-flow thermostat?

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Someone recommended that I use a "high flow" thermostat.
Just what is that? Do I need one?
I checked at Summit, Jegs, and Speedway, and they look light a regular thermostat. Some are the barrel type and some are the typical disc type.
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,413
Loc.
Statesville, NC
Hi, of course you don't "need" a super duper thermostat, but why not?
I used Stant thermostats for years with no complaints. Last time I went over the cooling system on my 66 Mustang I got a Motorcraft thermostat from O'Reilly's. It is a quality piece, made for your engine. You can see the difference.
Good luck
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,196
Ford recommends 195 degree thermostats and the SpeedwayMotors Robertshaw is 180. I have a FlowCooler water pump that came with the recommendation of a RobertShaw thermostat so I got my high flow RobertShaw 195 degree from them.
 
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blubuckaroo

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Because of my distributor advance problems I had after replacing the Duraspark pick-up coil, I decided to just have another distributor calibrated. That shop asks a lot of questions about your build, so they can put in the correct curves and limits. When he asked about the thermostat, he said I should be using a 180 degree rather than the 194 that's in there now.
His reason was that it's a carbureted engine, and it's got iron performance heads. He said if they were aluminum heads, the higher temperature would be more appropriate, because they dissipate heat better.
He recommended a 180 degree high flow thermostat.
 
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blubuckaroo

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Now I'm going back to square 1. I set the jets, metering rods, and metering rod springs with a wideband O2 gauge and vacuum gauge.
Changing timing and timing advance sort of nullifies my previous O2 readings.
I found switching to 194 from 180 made my engine feel peppier.
We shall see what happens when we go back but make adjustments to the timing and mixture too.
 

gr8scott

Contributor
Bronco Guru
Joined
Jul 1, 2011
Messages
1,823

They claim it flows 56GPM.

Ford recommends 195 degree thermostats and the SpeedwayMotors Robertshaw is 180. I have a FlowCooler water pump that came with the recommendation of a RobertShaw thermostat so I got my high flow RobertShaw 195 degree from them.

Summit has it too, just ordered one.

https://www.summitracing.com/parts/bra-330-195
 

Eoth

Bronco Guru
Joined
Mar 10, 2004
Messages
1,677
I found switching to 194 from 180 made my engine feel peppier.

Yup... Cooler engines produce more HP. Drag racers pay a lot of attention to how low they dare run their engines. The trade-off is emissions and engine wear. Also, as mentioned, ethanol is an issue... 180 is on the lower end necessary to "boil out" the extra condensation the ethanol is adding to the system. It a bigger concern with vehicles that are not used often or primarily run for short trips.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Robertshaw performance thermostats were rated full flow at stated rating temperature as opposed to stock thermostats that start to open at rated temperature. the flow windows have much more flow area when open than stock thermostats. they are not too much more money but less widely available when you need them. use to be able the get them anywhere before we allowed the Chinese to take over our auto parts market. Always check any thermostat before you install them.
 
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blubuckaroo

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Always check any thermostat before you install them.

I'm with you on that.
Too many things aren't working when we get them.
I just installed a new garage door opener, and couldn't get the limits to adjust. It arrived with a faulty control board, and they're sending me one.
 
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