https://forum.grantorinosport.org/info-thermostat-for-351-cleveland-351m-or-400_topic18289.html | |
This is the only style thermostat that should be used. The other hat designs do not flow enough coolant when open and cause the coolant path to continue to circulate in the block. The shaw design addresses the flow issue with the huge top opening allowing coolant from the radiator top hose to easily be pulled into the block. Having the lower hat to block the plate is a must but the big issue with this block is flow. The shaw thermostat was in the car from ford. If you look at the top of the others you can see how small the opening is compared to the shaw design. The Robertshaw 330 series looks like the 333 series from the top, but flip it over & they're not the same. The 330 series is the universal thermostat that fits small block Fords, small block Chevys and small block Mopars. That's also one way to determine what Mr Gasket & others are selling ... search which motors the thermostat fits. The 333 series fits 351C, 351M and 400 only. And a thermostat that fits 289/302/351 Fords, small block Chevys or small block Mopars will not work properly in a Cleveland. Ford has used the Robertshaw high flow thermostat in many applications since the 1960s, and I believe they still use it today. They all look the same from the top, but only the one designed for the 351C has the little 11/16" flanged button on the bottom. Its a small subtle difference that many people don't understand. This thermostat is unique to the 335 series motors (351C, 351M, 400) and no other motor uses it. Even Ford has sold the wrong thermostat over the counter in the 1970s! They actually boxed the wrong thermostat in the box of the right part number. My advice is to use the 333-192 thermostat. The original 351C thermostats were 192 degree thermostats. The above info is from George Pence on the Pantera forum and helps to select the correct thermostat. I run the 333-192. The reason for the 192 degree is the 335 series tends to collect condensation under the intake at 180 degrees and running around 192 clears that issue up. Hope this helps clear things up, it helped me out as I had the hat style small opening in before and it made a big difference in cooling stability in any situation when I switched to the 333-192 on my Cleveland. |
Hi 351C1971,
I tried to do it that way with heater hoses without a valve because I have no AC. It works but it not really right. The water suppose to recirculate under the Thermostat. The way your is now is it has a passage being vented or not the incorrect way. The Weiand water pump is a good part I have now a spare one with the hole drilled out. It is a 1/2" hole and not a 3/8" hole. The hole is drilled at a angle above the second port. I understand how you feel about removing pump. Mine pulled the timing cover loose because I forgot to remove one of the screws, and I had to do a timing cover gasket as well. I bought the Milodon HV (#16235) and a flowkooler robert shaw thermostat. I also discovered you can take a Mr Gasket 4365 thermostat and add the hat from wrong type slant thermostat and add it to it. ( this takes some doing) (it is nice to have OEM part to match up distance of foot) Drilling holes will help more flow but it will never warm up quickly. Shown below is a Weiand water pump with Hole drilled 1/2".
Steve
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Found a great explanation and description of how correct thermostat for 351C works! Check it out. https://www.coolcatcorp.com/thermostats/Ford.html
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