351 Cleveland thermostat restrictor

[Mister 4x4]

Excellent information as always! :bravo:

 

[Mystic Fish]

We are rebuilding a 351C and it appears that the restrictor hat is permanently attached to the engine block. When we tore the engine down I was aware of the removable hat, but noticed that what looks like the restrictor hat would not come out of the block.

The block has now been hot tanked and bored .030 and was curious if the hot tank process would loosen or even destroy the hat. It did not and is in the same place it was before the machine work.

It the spot in the block simply a mounting spot for the hat? It looks just like the pictures posted here of what the hat should look like, but is not removable. Is it possible that the hat is permanently mounted in the block?

How difficult is it to remove the restrictor hat?

I am at a bit of a loss and appreciate some input.

 

[jbojo]

Jeff,

That bypass orifice plug is pressed into place. I think that it is brass so it will get destroyed if you pull it off. I don't believe you need to remove it if it is still in good shape. I know I have 2 of them, I'll have to look for them if you need one, not sure where I stored them.

-john

 

[barnett468]

We are rebuilding a 351C and it appears that the restrictor hat is permanently attached to the engine block. When we tore the engine down I was aware of the removable hat, but noticed that what looks like the restrictor hat would not come out of the block.

The block has now been hot tanked and bored .030 and was curious if the hot tank process would loosen or even destroy the hat. It did not and is in the same place it was before the machine work.

It the spot in the block simply a mounting spot for the hat? It looks just like the pictures posted here of what the hat should look like, but is not removable. Is it possible that the hat is permanently mounted in the block?

How difficult is it to remove the restrictor hat?

I am at a bit of a loss and appreciate some input.

it "should" pull right out with a J hook and a light pull . you could even try a bent coat hangar.

why do you want to remove it?

i never use them because they too frequently cause hot running conditions.

 

[Mystic Fish]

Jeff,

That bypass orifice plug is pressed into place. I think that it is brass so it will get destroyed if you pull it off. I don't believe you need to remove it if it is still in good shape. I know I have 2 of them, I'll have to look for them if you need one, not sure where I stored them.

-john

Thanks John, I don't think I need one, but wanted to be sure it was correct and didn't really know how difficult they are to remove. The only reason I considered removing it was I didn't want it to get lost or damaged during the hot tank, but since it is still there I wanted to be sure it was correct.

Looks like we need to get the correct thermostat before the final assembly.

One question though, shouldn't it be directly beneath the thermostat hole? It looks like it is offset towards the front of the block a bit. I will get pictures of it next week if I get time.

 

[barnett468]

you are taking a big chance of your engine running hotter than it should by using it which is the sole reason, they made a block of plate to replace it with and why there is probably not one pantera in the country that uses it.

before the block off plate was made, people would solder a penny over the hole.

 

[EBSTANG]

http://www.ebay.com/usr/neonfiddler?_trksid=p2057872.m2749.l2754

Go to this Ebay site. I have no affiliation with this man, other than I purchased the brass washer, a 180° & 195° thermostat from him. Now listen......I testify with my reputation on the line, that these are quality, better than new. The brass washer is a higher quality, more finely machined piece, period. The skirt, is machined and pressed onto the correct robertshaw thermostat. This skirt is thicker than stock material and is much higher quality than the others available on Amazon and at Napa, I know because I have the Amazon ones and the Napa ones on my shelf in my shop. I spent big bucks on my engine and I obsessed over this issue a year ago. I bought all of them and tested them.

This guy on Ebay is a machinist and a Pantera enthusiast but he does not believe in the aluminum blocking plate. Either do I. (I also have one of these plates and contemplated using it) Get this next concept clear in your mind: It is not a restrictor plate, it is a bypass washer. A restrictor plate is something altogether different. My Cleveland, with 425 HP runs perfectly using these parts, I currently use the 180°. Again, I have no reason to recommend this guy other than when you have the parts in your hand and you compare them to others, his are of better quality.

His washer and thermostat will cost you $100 (last year), now they are around $120. I know it sounds like a rip off but what do you think he should sell them for...his machinist time is worth it for my engine. If it is not worth his time to make them, why would he? He doesn't make runs of millions of these, each one is machined. Go to his site and read. Educate yourself. Don't cheap out.

 

[barnett468]

the bypass plate works perfectly fine . if it did not, 50 zillion panteras would not be using it including the president of the pantera club or jerry hall of halls panteras . the original system also works fine when the parts mentioned above are used . the factory parts didn't work well . the prob is not the concept, it is the crappy parts ford used to build the system with.

 

[EBSTANG]

http://www.ebay.com/usr/neonfiddler?_trksid=p2057872.m2749.l2754

Go to this Ebay site. I have no affiliation with this man, other than I purchased the brass washer, a 180° & 195° thermostat from him. Now listen......I testify with my reputation on the line, that these are quality, better than new. The brass washer is a higher quality, more finely machined piece, period. The skirt, is machined and pressed onto the correct robertshaw thermostat. This skirt is thicker than stock material and is much higher quality than the others available on Amazon and at Napa, I know because I have the Amazon ones and the Napa ones on my shelf in my shop. I spent big bucks on my engine and I obsessed over this issue a year ago. I bought all of them and tested them.

This guy on Ebay is a machinist and a Pantera enthusiast but he does not believe in the aluminum blocking plate. Either do I. (I also have one of these plates and contemplated using it) Get this next concept clear in your mind: It is not a restrictor plate, it is a bypass washer. A restrictor plate is something altogether different. My Cleveland, with 425 HP runs perfectly using these parts, I currently use the 180°. Again, I have no reason to recommend this guy other than when you have the parts in your hand and you compare them to others, his are of better quality.

His washer and thermostat will cost you $100 (last year), now they are around $120. I know it sounds like a rip off but what do you think he should sell them for...his machinist time is worth it for my engine. If it is not worth his time to make them, why would he? He doesn't make runs of millions of these, each one is machined. Go to his site and read. Educate yourself. Don't cheap out.

The quality of the machined skirt is obvious compared to the Amazon and Napa ones.

the bypass plate works perfectly fine . if it did not, 50 zillion panteras would not be using it including the president of the pantera club or jerry hall of halls panteras . the original system also works fine when the parts mentioned above are used . the factory parts didn't work well . the prob is not the concept, it is the crappy parts ford used to build the system with.

True, crap parts will cause issues.

Panteras have inherent cooling issues with the added coolant path distance.

The stock bypass helps the coolant passages through the block warm up EVENLY, and prevents hot pockets that can/will occur without circulation. (aluminum blocking plate)

The aluminum blocking plate doesn't allow any coolant circulation through the block until the thermostat opens. This is why it is recommended to drill holes in the thermostat, when using the Al blocking plate. This will give you SOME circulation. (in this case, through the radiator, to the water pump and back to the block)

Opening the heater core valve (turning the heat on) will allow circulation from the block (when thermostat is closed), through the heater core, to the water pump and back to the block, just like the bypass does, but you have to turn your heat on.

 

[barnett468]

the design is to allow the heads to warm up evenly . this is to prevent them from cracking due to the thin walls in the water jackets.

the block off plate has cured many pantera hot running probs in spite of the poor design of the rest of the cooling system.

the brass colored thermostat you have also looks like a high flow one and just using a high flow thermostat has helped reduce temps in many cases so its not possible to contribute a hot running cure to the machined brass parts alone.

 

[EBSTANG]

the design is to allow the heads to warm up evenly . this is to prevent them from cracking due to the thin walls in the water jackets.

the block off plate has cured many pantera hot running probs in spite of the poor design of the rest of the cooling system.

the brass colored thermostat you have also looks like a high flow one and just using a high flow thermostat has helped reduce temps in many cases so its not possible to contribute a hot running cure to the machined brass parts alone.

Yes, it is the high flow Robertshaw thermostat that the Ebay seller (the machinist) adds his machined skirt to. This high flow design with the skirt is how the Cleveland's cooling system was originally equipped. The others, although they are quite cheaper, are not as refined and it was important to me to have the skirt, of the thermostat, flawlessly mesh with the orifice in the brass bypass washer. When you want something to mesh flawlessly, you go to a machinist AND pay him to do it right.(he's already done it) ***THESE PARTS WILL NOT "CURE"^ HOT RUNNING PROBLEMS IN ALL CLEVELANDS. :shootself: THEY MAY WORK BETTER THAN CRAPPY PARTS THAT MAY NOT MESH TOGETHER WELL***

Personally, I have done everything I could in planning and building my engine to assure no overheating. In fact, last summer I was in 2 cruise nights, 95°+ temps on the road, sitting in traffic (parade of hot rods), with my windows up, Classic Auto Air blasting (it was literally cold), for over 2 hours and my temp never rose above 180°. 3 core brass radiator and dual Spal fans with a Painless controller. I too, was amazed.

http://www.amazon.com/Spal-30102130-Dual-Extreme-Performance/dp/B003PB9S8G?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00

http://www.amazon.com/Painless-30140-Dual-Fan-Controller/dp/B003XLE2LQ/ref=sr_1_1?s=automotive&ie=UTF8&qid=1458907253&sr=1-1&keywords=painless+30140

Well worth it.

So, maintaining bypass is part of a system (that needs to be understood) and may not "cure" an overheating problem but you start by doing all the little things right and you'll end up with a more dependable machine.

This "brass bypass washer" subject has mucho content on this site written about it. There are strong opinions. People like to defend their point of view. All I'm saying is you'll have a better chance of it working as the engineers intended to, if your parts work together nicely. Get good parts. Pay the $125 for the good washer and thermostat and know you made the best choice for your beloved engine...a small price to pay.

If any of you want the Aluminum Pantera blocker plate, I have a brand new one, in the box, from WCCC (who did not invent/make it-they only sell it AND none of the WCCC guys use it in their Clevelands), that I won't be using.

Our purpose here is to help others gleen information and make decisions as to how to proceed in their builds. My only intent, is to help, as many here have helped me. Read everything you can and never just listen to one person's opinion. Discern the truth from all the information you gather and proceed how you see fit. (to me that's where the fun is, you get to chose for yourself) Good luck on your builds, keep the passion and do it right or don't waste your time.

By the way, respectfully, your last sentence would make more sense with the word "attribute" as opposed to the word "contribute."

 

[Mister 4x4]

I remember this thread, but I think I mentioned my results in a different thread shortly after this one ran last September. I got the parts from WCCC and installed the "Pantera Fix," and I have similar results as John - mine warms up to a place right between the "T" and "E" on the Temp gauges, and stays put while its running. ::thumb::

The only times I've driven it, were quick trips around the neighborhood, getting to and from the place that did the safety inspection, and stopping off at a friend's house along the way. I don't think I ran the car up to more than 35mph during any of the trips (speedometer cable still not installed), but the temp gauge never budged. Compare that to simply loading/unloading it on/off a trailer to go to a car show, and the temp gauge ran up past "P" just rolling through the parking lot and back onto the trailer (the heater circuit works really well, though ).

So far, so good.

 

[Paul of MO]

For what it is worth:

Stant 180 29468 Cleveland specific

Stant 192 29469 Cleveland specific

Stant 180 13468 Cleveland specific - (What I use - 6 bucks and is correct for 351C)

Stant 192 13469 Cleveland specific

Stant 192 S-346-192

Gates 180 33128 Cleveland specific

Gates 192 33129 Cleveland specific

RobertShaw 180 333-180 Cleveland specific

Ford/Motorcraft 180 RT-310 Cleveland specific -

Ford/Motorcraft 192 RT-139 Cleveland specific; 70-73 351C,351CJ, & Boss 351

Ford 180 D7PZ-8575-A Cleveland specific

Napa 180 197 Cleveland specific

- Paul of Mo

 

[Mister 4x4]

Thanks Paul, for capturing all those part numbers - I'm sure it will help someone who might not be ready for the Pantera Mod and just looking to replace their factory-style thermostat. ::thumb::

(At least a guy would have a chance at ordering the no-kidding correct thermostat when the guy at the parts store tries to sell them a Windsor thermostat instead... because that's what the computer says :whistling: ).

 

[barnett468]

installing electric fans does not make a system more reliable since they can fail . also, since good electric fans flow more air at low speed than a stock fan does, they will cool the engine better at low speeds, so again, you can NOT attribute improved cooling or efficient cooling to the custom made parts as it seems like you are trying to do.

Also, i don't know what you mean by saying that none of the west coast cougar guys use the aftermarket bypass, because this is wrong . i was in the west coast cougar club and i used it and i know several other people that used it.

there are many things the engineers designed on the cars that are less than ideal for one reason or another, so not everything they did was great just because they were engineers . if everything they did was great, no one would have had problems with the original bypass design working properly because ford would have machined the parts for it instead of stamping them etc.

no one would be lowering the upper control arm pivot point to drastically improve steering with ZERO adverse effects.

not every single 289 mustang would have overheated if you drove it with the ac on in 110 degree weather.

the auto trannys would have always fully engaged the parking pawl when they were put in park instead of sometimes coming out of park allowing the car to roll freely down hills until something stopped it which was often another car or a building.

the pinto would not have ever exploded when it was rear ended.

the rear door latch on one late model vehicle would not have randomly opened dumping any kids that might have been leaning against it, onto the road.

the list of factory flaws is virtually endless.

these cars came with bias ply tires but i dont know a single person that uses them other than a concours guy.

 

[EBSTANG]

Ok, you're right.

 

[Stanglover]

installing electric fans does not make a system more reliable since they can fail . also, since good electric fans flow more air at low speed than a stock fan does, they will cool the engine better at low speeds, so again, you can NOT attribute improved cooling or efficient cooling to the custom made parts as it seems like you are trying to do.

Also, i don't know what you mean by saying that none of the west coast cougar guys use the aftermarket bypass, because this is wrong . i was in the west coast cougar club and i used it and i know several other people that used it.

there are many things the engineers designed on the cars that are less than ideal for one reason or another, so not everything they did was great just because they were engineers . if everything they did was great, no one would have had problems with the original bypass design working properly because ford would have machined the parts for it instead of stamping them etc.

no one would be lowering the upper control arm pivot point to drastically improve steering with ZERO adverse effects.

not every single 289 mustang would have overheated if you drove it with the ac on in 110 degree weather.

the auto trannys would have always fully engaged the parking pawl when they were put in park instead of sometimes coming out of park allowing the car to roll freely down hills until something stopped it which was often another car or a building.

the pinto would not have ever exploded when it was rear ended.

the rear door latch on one late model vehicle would not have randomly opened dumping any kids that might have been leaning against it, onto the road.

the list of factory flaws is virtually endless.

these cars came with bias ply tires but i dont know a single person that uses them other than a concours guy.

That's why there is an age old saying " You can always tell an engineer..........., but you can't tell them much"!! Seen THAT too many times where I worked.


I've had no obvious problems with my 351C running a 180 stat and although my parts store gave me a stat listed as for the Cleveland, to be honest, I had no idea that there was the requirement to block off the restrictor hole. This is news to me. As many will know, my engine is currently being rebuilt, so I will now ensure that the correct Cleveland specific thermostat is used..... if I can find one in Canada. To me, this seems to be counter to logical thinking, but what do I know!!

Thanks for bringing this thread to our attention.

Geoff.

 

[barnett468]

That's why there is an age old saying " You can always tell an engineer..........., but you can't tell them much"!! Seen THAT too many times where I worked.

LOL

I've had no obvious problems with my 351C running a 180 stat and although my parts store gave me a stat listed as for the Cleveland, to be honest, I had no idea that there was the requirement to block off the restrictor hole. This is news to me. As many will know, my engine is currently being rebuilt, so I will now ensure that the correct Cleveland specific thermostat is used..... if I can find one in Canada. To me, this seems to be counter to logical thinking, but what do I know!!

Thanks for bringing this thread to our attention.

Geoff.

you only need to block the restrictor hole if you use a windsor stye t stat instead of a cleveland style one . i just fixed a car that would creep up in temp a little bit in traffic ad it had a windsor t stat with the factory bypass plate s i pt the factory cleveland t stat in it and it cured the problem . there are a lot of variables that affect water temp . i have been fixing overheating probs fo 40 years so i have pretty much seen it all and some of it wasn't very pretty.

 

[Mystic Fish]

So, in summary, the right thing to do is run a Cleveland specific thermostat and there are no issues?

The block off device is needed if you divert from the stock setup?

:chin:

 

[Paul of MO]

So, in summary, the right thing to do is run a Cleveland specific thermostat and there are no issues?

The block off device is needed if you divert from the stock setup?

:chin:

Before someone post a novel - the answer to your question is....................................wait for it.......................................here it comes............. Yep!

-Paul of MO