I installed a set of special 180 degree stats made by Bob Shewman 2 weeks ago to test in my 39 convertible. It turned out to be an ideal time to test them as I searched for the fuel boiling problem. These were easy to install and they go in the radiator hoses at the radiator end of the hoses and fit all early V/8s from 1932 to 1948. They fit snug in the hose and the front end sits up against the radiator hose neck so they need no clamps and will no move. You will need good 1 3/4" ID hoses that are not shrunk, soft or distorted. You only have to drain a little over a gallon of coolant to install them. These have a LARGE flow opening and DO NOT RESTRICT the coolant flow like all other modern stats with small flow openings which cause elevated temperatures in hot weather. They are vented so some coolant flows as soon as the engine is started getting hot water to the stats in less then 5 minutes. The temperature in my 39 remained at 178 to 182 for the entire duration over the past 2 weeks of the fuel testing. These are all copper and brass of the newer wax type mechanisims, not the old bellows type that fail from work hardening on the edges of the bellows. Bob tested them in Pa. at 40 to 50 degree outside temperatures and said they came up to 180 in about 6 or 8 minutes. He is produceing a limited supply at $50.00 per set of 2 including shipping. Contact Bob at gadgiteer@aol.com G.M.
Thermostats
- Thread starter G.M.
- Start date
peewee2you
Well-known member
G.M. did you get any photo's before you put them in, so we could see how they look and possibly are put together
37 Coupe
Well-known member
Wouldn't this seem to put more pressure and heat on the hose itself? I know you have mentioned that good fitting hoses need to be used but seems to me this could lead to a problem in time. Ford engineers put them in the hose closest to the head for a reason why would anybody try to re-engineer this? I like Bob's fuel hose but don't think I will jump on this.
37 If you like Bob's fuel hose you will love these stats. I said in the post these were vented for preflow before they open. There is not any extra heat as they are full flow, almost the same as the ID of the hose. A water pump won't pump very much pressure if the hose is blocked they will just spin their wheels like a tire in the snow. Pressure is a product of heat and below 180 there no pressure as they are vented. Above 180 they are fully open so there is no additional pressure under any condition unless it boils over and there would be no difference with or without stats. At 210 degrees there will be about 3 lbs pressure in the entire system much above that and the 4 lb pressure cap or Skips 3 lb valve opens to protect the system letting the excessive pressure out the over flow tube. An early radiator with the over flow comming off the tank is open all the time and there is almost no pressure until it boils over. This open over flow also lets water freely exit the radiator leaving it low on water and runs hotter with less water. This is the main purpose of Skips 3 lb pressure valve, keeping ALL of the water in the system and like a pressure cap also acts like a saftey valve to release pressure in the system over 4 lbs with a pressure cap and 3 lbs with the valve. This is the same as why would anyone re-engineer the VERY POOR water pumps or the coils that caused millions of problems since they were new in hot conditions. G.M.
Old Henry
Well-known member
I wouldn't do this either. All thermostats are installed in the engine block so that they open as soon as the engine block warms up. Having them at the end of a hose as far from the engine block as it can get delays their opening and causes the temperature of the block to be much higher before opening the thermostat than is designed. It's kind of like having the thermostat of your house next to a window instead of in the middle of the inner hallway. Sure, it'll still work but you know how hot the middle of the house would get before the thermostat by the window warmed up enough to shut off the furnace. Not good.
Here is the FlowKooler Robert Shaw Series High Performance Thermostat (not the Bob Shewman ones) that has a bigger opening than a stock syle when it's open but it is not installed in the hose. It is installed in the engine block just like all thermostats.
Get it here: http://www.summitracing.com/parts/BRA-330-160/?rtype=10
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Old Henry
Well-known member
Many have reported the problem they have with drilling holes to "vent" their thermostats causes enough water to pass through them to the radiator in the winter that the engine doesn't warm up enough to get heat out of the heater - one of the main purposes of thermostats. See here: http://www.fordbarn.com/forum/showthread.php?t=58067&highlight=thermostat
Tests done in warm weather (including the 40-50 degrees Bob tested them in) don't illustrate this problem with "vented" thermostats. The real heat is needed when it's actually cold outside, like below 30 degrees.
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Shadetree, what you don't see is the water that is pushed out going down the road with an open over flow with no pressure cap or valve. If it comes out a little while after it is shut down that is from the temperature rise after the engine shuts down. This is in the same time frame the carb boils the gas down into the intake manifold.
there are a lot of pressure caps that don't go down and seat on the bottom washer like seal in the neck. With a proper working pressure valve or pressure cap you should not have water comming out below about 210. If you do you have a compression leak. Very little pressure from the pumps as I said pressure is from heat and extreme pressure is from steam. I would say the entire system is under the same pressure even though the top of the radiator is hotter than the bottom with the cap or valve. If there was any slight difference in an open system it would hard to measure which would less than in the 200 range. G.M.
there are a lot of pressure caps that don't go down and seat on the bottom washer like seal in the neck. With a proper working pressure valve or pressure cap you should not have water comming out below about 210. If you do you have a compression leak. Very little pressure from the pumps as I said pressure is from heat and extreme pressure is from steam. I would say the entire system is under the same pressure even though the top of the radiator is hotter than the bottom with the cap or valve. If there was any slight difference in an open system it would hard to measure which would less than in the 200 range. G.M.
Henry your just guessing, thinking and talking, I can back up my claims from live tests and believe me they work PERFECT. The stat picture you show looks like an off shore copy of a Robertshaw and I have heard of failures with these. The good Robertshaws were all brass. About a year ago the Robertshaw stat division which was last owned by Cooper Tire was sold. The small company from what I heard moved what was left of it to Mexico. I don't remember the name of the company but several different brand names like the one in your picture have poped up in the past 6 or so months. G.M.
Old Henry
Well-known member
G.M. Is this not the 330-160 thermostat that you recommended just a month ago with these words:
"What you need is 330-160 stats which have large openings amd allow the full flow of coolant. The hot rod suppliers sell them. G.M." Here: http://www.fordbarn.com/forum/showthread.php?t=58067&highlight=thermostat
Talk about just guessing, thinking, and talking . . .
Are you changing your tune? Or, did you just forget?
I guess everyone is free to decide what makes more sense - a thermostat in the engine block like every thermostat has ever been until Bob Shewman, or his way.
If you would prefer a Robertshaw in all brass here it is: http://www.quadratec.com/products/51211_50.htm
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Old Henry
Well-known member
I guess you're right. I guess my 45 years of driving a flathead engine with stock thermostats that work PERFECT is nothing compared to your two weeks of testing the first thermostats you have ever run in your car.
Charlie ny
BANNED
Lots of room for different opinions. I use Chevy stats in my 8ba and
they work great for me. The BIG improvement was the black plastic
shroud I got from Walker Radiator at Flatjack's suggestion.
If anyone here has the opportunity to sit down and talk to George
Mitchell take the time.....he's quite a guy.
Charlie ny
they work great for me. The BIG improvement was the black plastic
shroud I got from Walker Radiator at Flatjack's suggestion.
If anyone here has the opportunity to sit down and talk to George
Mitchell take the time.....he's quite a guy.
Charlie ny
Charlie, The 49 to 53 heads with the goose neck allows you to use thermostats with the large flow openings that do not reduce the flow of water. This thermostat problem in the 32 to 48 engines is not a 2 week deal. Years ago I wrote on I believe it was this site when for months I expermented with Napa #111 160 degree stats with the standard small flow opening as any modern stat I have seen that will fit the early engines. I drilled 8- .140 holes in the flange of both stats to try to increase the flow in my 39 pick up that will run at a fast idle for 2 hours and never get over 180 on a hundred degree day. This truck has a shrould, Skips pumps, industrial 6 bladed fan and a 4lb pressure cap. The water is filled right up to the filler neck and don't move for months. With the 160 stats installed on a 90 degree day it would go over 190 going down the road with a full flow of air comming in. Without the 160 stats under the same conditions this truck runs below 175. Opinions are differant then results. G.M.
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Bassman/NZ
Well-known member
As a sidebar to this conversation, what is the optimum temp for a flattie? I know for modern engines it's in the 185 degree area... would this hold true for our engines? I've never noticed any Ford specs for this. My flattie sits around 170 most of the time, and I cant help wondering if it should be a bit higher. I do not run thermostats, but I might get a pair of Bob's if it's going to make my engine run a bit more efficiently.
Old Henry
Well-known member
I'm not sure how one would determine such optimal operating temperature but here is some evidence of what The Creator thought it should be if the temperatures He made thermostats to open is any clue.
'32-'37 140-145 deg.
'37-'40 60-90 hp 148-152 deg.
'37-'47 100 hp 154-159 deg.
'37-'48 with pressure cap 8 cyl 148-153 deg
'37-'48 w/o pressure cap 158-162 deg
'47-'48 6 cyl. with pressure cap and antifreeze 177-182 deg.
See below. I think all of that is a pretty good clue of what Mr. Ford thought ideal operating temperature ought to be. In the winter my 160 deg. thermostats open just enough to keep my temperature at 140 deg.
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