Shewman's High Flow Thermostats

[gearhead1952]

Originally Posted by flatjack9

No.

The napa premium 180 stat THM 530080 at $9 each has moved to the top of my list.

[Old Henry]

Originally Posted by gearhead1952

In looking at the pics of these high flow stats they look like they have large openings on the top but the bottom looks very restrictive am I missing something?

Yes. The Robert Shaw 330 stats work very differently than the stats for pre-49's. What you see that seems quite restrictive on the bottom is a cup that contains the wax pellet that opens the stat. The stat is opened by moving the cup down and away for the top flange so that the coolant then flows all around the cup and up through the large opening in the flange. None of the flow goes through the cup. It moves totally out of the way. But, this kind of stat will not work in hoses or in the head necks of the pre-49 engines because the cup then blocks the flow. But in later engines, the cup sits down in the block rather in a tube so that when it moves down the coolant can flow all around it and up through the larger opening. See discussion, pictures and diagrams beginning with post # 23 on this thread.

[51 MERC-CT]

Originally Posted by gearhead1952

The napa premium 180 stat THM 530080 at $9 each has moved to the top of my list.

You are missing something. The Napa stat looks like a standard stat and probably flows 25 to 45% less than the Robertshaw. stat.

[gearhead1952]

Gotcha. Thanks for the clarification. None of the places I went to described how the high flow units worked. Ok they are back to the top of my list.

[Old Henry]

Originally Posted by 51 MERC-CT

It may be possible to modify the later high flow thermostat to fit inside the 59AB hose.

That's what Shewman has done.
Just received a pair of Shewman's stats from another barner who decided not to use them and sent them to me so that I could get some macro photos and measurements to see how they compare with the Stant/NAPA stats that I've reported on.

Shewman's "high flow" thermostats are a Robert Shaw 330-FHT 180° thermostat (says it right on the side) from which the flange has been cut off and a brass tube brazed in it's place.



In this photo you can see the brazing of the tube where the flange was. You can also see the three holes drilled in the side of the middle bracket that, as best I could measure down in there, are about 6 mm. When the thermostat is totally closed water continues to flow through those three holes that are a total of 84 sq.mm. through the three larger holes seen in the bottom of the cup.



When the thermostat is fully open the bottom cup just moves down opening up a gap between it and the tube.





If that cup were moving into a wide open space full of water as the Robert Shaw stat is designed to do in an 8ba engine it would work fantastic. Unfortunately, with Shewman's stat installed inside of the hose, that big cup is still in the way of the flow that must go around that cup and through a 2.5 mm gap between that cup and the inside of the hose. The area of that gap is 317 sq.mm. In addition to that space are the three holes drilled into the inside bracket totalling 84 sq.mm. So, the total area for water to flow through Shewman's stat is 401 sq.mm whereas the Stant stat has 615 sq.mm. - more than 50% greater flow space/area than Shewman's. Plus, the Stant stat shuts totally off to allow full heat up in the winter whereas Shewman's stat leaves itself open to allow 20% of its total flow even when it's totally closed. Plus, the Stant stats are $18.00 a pair compared to Shewman's at $50.00 per pair. As from the start - not condemning, just informing.

Just thought someone might like to know.

[oldford2]

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Professor,
Why can't you let go on subjects covered ad nauseam.
" Ad nauseam is a Latin term for something unpleasurable that has continued "to [the point of] nausea".[1][2] For example, the sentence, "This topic has been discussed ad nauseam," signifies that the topic in question has been discussed extensively, and that those involved in the discussion have grown tired of it."


" Just received a pair of Shewman's stats from another barner who realized they were not the high flow represented so that I could get some macro photos and measurements to see how they compare with the Stant/NAPA stats that I've reported on.

Shewman's "high flow" thermostats are nothing more than a Robert Shaw 330-FHT 180° thermostat (says it right on the side) from which Shewman has removed the flange and brazed a brass tube in it's place."
So you have great pictures and measurements but have you tested them?? Stick to your great travel pictures and stories. When you have tested them report back. Then we can move on to vapor lock.
John

[G.M.]

John, Henry has been on a mission to put a hurt on Bob's stats for months. These are the original Robertshaw 330-180 stats all heavy brass and copper not the Mexican copies as shown on other posts with the light colored tops.. These are the highest flow stats I have seen that fits in the hoses of 32 to 48 Fords. I have 3 or 4 sets and a lot of friends bought and tried them before Bob started selling them all with good reports. My cars all run between 178 and 182 on 90 to 95 days. I did extensive testing on the Napa 111 stats a number of years ago and even put them in my 39 P/U which will run at a fast idle for 2 hours and never get to 180 with no stats on 100 degree day was running up near 200 on a 90 degree day with the Napa 111's with 6 or eight hole drilled in the flange to try to get more flow. G.M.

[Old Henry]

Originally Posted by oldford2

Professor,
Why can't you let go on subjects covered ad nauseam.

Because many people want to know and are not quite as "queezy" as you are as indicated in the previous acclamations of the info presented and inquiries for further information in this thread:

Originally Posted by Bluebell

Good thread!

Originally Posted by flatjack9

Keep up the quest Old Henry. I'm pulling for you. Drilling holes all around the thermostat to make it high flow is a joke.

Originally Posted by VeryTangled

Wow that is GOLD.

Having a good time following this thread and learning a lot.

Prof. Henry, is there any chance you can post more photos when you get them? I'd be especially interested in seeing one in the open position.

I'd also be interested in their opening temperature, and their closing temperature. It seems you will be interested in them closing correctly as the fluid cools on descent, preventing the temperature from dropping into an abnormally cool operating range, after being open during ascent. As I read it this is one of the areas you're looking for to get good performance.

-VT/JeffH

Originally Posted by Old Henry

Pictures save a lot of words (such as in post # 59). It would be interesting to see such close-up detailed shots of Shewman's stats to see what they're really like.

Originally Posted by gearhead1952

Great info Old Henry.

Originally Posted by gearhead1952

In looking at the pics of these high flow stats they look like they have large openings on the top but the bottom looks very restrictive am I missing something?

Originally Posted by gearhead1952

Gotcha. Thanks for the clarification. None of the places I went to described how the high flow units worked.

Without actual comparative flow tests, which no one has done, flow can only be predicted by the size of the passages that the flow goes through. My measurements of Shewman's and Stant stats are the first I have ever seen and give a more accurate prediction of flow than someone's testimonial that they have used them and they seem to work fine.

Like I said at the end of my last report - someone might like to know. If you don't want to know, ignore it, but don't criticize when you have no actual empirical data to contradict my measurements and conclusions. Until someone actually does comparative flow tests, my data stands as the best indicator of flow so far.

I have no "mission to put a hurt Bob's stats." In fact, if you read my first post, I was actually considering buying them to use. I just wanted to know the truth about them compared to other stats before I did. Now I know. Maybe someone else would also like to know. If they do, now they can. If they don't, I don't know why they would even open up this thread.

As for your nausea - take two Alka-Seltzer and call me in the morning.

[Roger/Sacramento]

I am all about learning how stuff works.......keep up the discussion until the answers appear. Doesn't make me sick.

[HotRodmicky]

So , where can i buy 49-53 robert shaw 330 180degrees Thermostats?

[51 MERC-CT]

Originally Posted by HotRodmicky

So , where can i buy 49-53 robert shaw 330 180degrees Thermostats?

Summit Racing

[51 MERC-CT]

Keep the info coming.
In regards to the 3 bypass holes, this is a stat. made by Robertshaw, modified and sold by EMT/Stewart.
It has the 3 bypass holes, which may or may not contribute to cooling but probably allow (because of flow) the sensor to see hot water sooner and open valve sooner in the cycle.

[G.M.]

Originally Posted by HotRodmicky

So , where can i buy 49-53 robert shaw 330 180degrees Thermostats?

Bob Shewman 1-610-933-6637 [email protected] Has the original NOS Robertshaw 360-180 all heavy brass and copper stats. These were built to military specs for trucks. He has them for the 49 to 53 Fords and modifies them to mount in the hoses of 32 to 48 fords. He also tests every stat before shipping to see that it operates in the 180 range. I use them and my engines stay between 178 and 182. G.M.

[Old Henry]

Next time we get a 90° day here (may not be until next summer) I may install Shewman's stats and do the Squaw Peak Road run (4 miles of 10% grade) to see how they compare to the Stants that I tested on the same road and temperature this summer and let you know.

[gearhead1952]

Originally Posted by oldford2

Professor,
Why can't you let go on subjects covered ad nauseam.
" Ad nauseam is a Latin term for something unpleasurable that has continued "to [the point of] nausea".[1][2] For example, the sentence, "This topic has been discussed ad nauseam," signifies that the topic in question has been discussed extensively, and that those involved in the discussion have grown tired of it."


" Just received a pair of Shewman's stats from another barner who realized they were not the high flow represented so that I could get some macro photos and measurements to see how they compare with the Stant/NAPA stats that I've reported on.

Shewman's "high flow" thermostats are nothing more than a Robert Shaw 330-FHT 180° thermostat (says it right on the side) from which Shewman has removed the flange and brazed a brass tube in it's place."
So you have great pictures and measurements but have you tested them?? Stick to your great travel pictures and stories. When you have tested them report back. Then we can move on to vapor lock.
John

I welcome any and all info. Keep it coming Henry. I bought a pair of Shewman's stats for my 8ba project.

Oldford did you know you don't have to read every thread and every post? Your post was unnecessary.

[Old Henry]

Originally Posted by gearhead1952

I welcome any and all info. Keep it coming Henry. I bought a pair of Shewman's stats for my 8ba project.

Good move. Should work great in the 8ba. That's the environment they were designed for.

[Old Henry]

In response to oldford2's repeated request for real life evidence of the problem with Shewman's thermostats I offer the following thread that just concluded with Shewman sending replacement thermostats for the 59A engine without the extra holes drilled in it so the engine would warm up in the winter which it wasn't doing with the holes drilled in it. There were several having that problem. It remains to be seen how they'll work in the summer without the extra holes. Here's the thread for anyone interested: https://www.fordbarn.com/forum/showthread.php?t=121447

[mark180]

Old Henry,

Thanks for all your work on this subject. My '37 runs cool in the winter (about 130° when the heater is on). I went to replace the thermostats with higher temp ones, only to discover I was running with no thermostats. That would explain why I was running cool.. I got some 180° stats from Speedway, and after running for a bit, the car would overheat, but after it cooled a bit, the stats would work fine. I'm looking for new stats now, and your research has been a HUGE help.

Mark

[gmc1941]

Thanks Henry (consumers that report to the flock are an asset) this is why we have the Ford Barn HELP IS ALWAYS ON THE WAY

[Kahuna]

I realize this is an old thread, But I've been using the Subaru Thermostats all summer and they work and regulate real well.