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Unfortunatly I was unable to attend the PI Christmas party. About 8 days before it, my brake master cylinder failed. Got a new one, bottle bleed the brakes, problem cured. As I was bleeding the right front cylinder, I noticed that my radiator had some bad corrosion on the right lower tank, and a very minor leak. So about 12/8 I pulled the radiator and brought to a shop for repairs. While the system was empty, I decided it was time to change the thermostat(weather it needed it or not). Well guess what guys, someone had installed the wrong type! As some of you may remember I was having cooling problems, temp gauge reading very high at times, but the radiator was cool. Well no wonder why, the thermostat was not blocking off the bypass port so not all of the coolent was being circulated!
Well, I got the correct thermostat from the Ford dealer, with the 3/8 hat on the bottom of it. Reinstalled the radiator, bleed all the air out several times and road tested. The car is now running right at 190 steady.
I did want to block off the bypass port, but I could not find a 3/8 brass freeze plug. In the factory shop manual, it actually shows a picture of installing a plug into this port during an engine rebuild....interesting.
Anyway, I wish all of you a safe, healthy Happy New Year.
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Tim,

the last time we covered the topic of thermostats, I didn't have a digital camera available. So now is a good opportunity to throw up some pictures of the proper thermostat for a 351C.

If the thermostat in your 351C does not look like the one in the pictures below, you have the wrong thermostat, and as Tim pointed out, your engine is constantly bypassing a significant amount of coolant from circulation through the radiator.

Happy New Year Tim.

George

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  • thermostat_collage
...since I have installed a Weiand aluminum waterpump I don't need the specific thermostat because the pump already blocks the reciculation port; so 100% of the engine coolant goes to the radiator. I did stay with a 180 Degrees Thermostat(we all know the colder the engine runs the more the cylinder bore wear; the 'chart' shows less than .0001" wear difference between 180 degrees and 160; OVER a 40 Hour test period.) My gauge reading is always at 170 to 190. I run one cooling fan (comes on with the key) I seldom if ever have to turn on the second fan(Manually). They are of the 'Miriya' pusher type and still on the original brass radiator. Yes! I am looking to replace it with a nice 'Fluidyne', in the very near future. 32 years is long enough to ask a Radiator to do it's job...
Your local Kragen or Pep Boys should have one, the former is where I just got mine.

Part # 333-180 Robert Shaw or # 330-180 for the Prestone Peformance equivalent. Go with the part No.s in hand as likely if you ask for a Pantera or 351C t-stat the guy will give you a regular Windsor type Frowner...just speaking from experience, that is why I researched the actual part No.s. and went back knowing exactly what I needed.

Julian
quote:
Originally posted by jwr2968:
Surley Wilkenson wouldn't have sent me the wrong thermastat?


Yes, Steve sold you the wrong t-stat.

and please don't call me Shirley!

lol.......

(thats an old Leslie Nielsen joke)

On a more serious note, the wrong thermostat has been handed out for the Clevo ever since the motor was new, I think the first time I came across this problem was around 1973. Steve may or may not be aware that's not a Clevo t-stat. Its very possible he was shipped the wrong part & never checked the boxes to verify he had received the correct parts. OR, he may feel that the Windsor t-stat he shipped you is the only one available, many vendors are under that impression. It's not common knowledge that Robertshaw is making the proper Clevo t-stat.

The brass orifice beneath the t-stat is no longer available new, if it is damaged or missing, an owner is left with fabricating one from a freeze plug, or scrounging for one at a wrecking yard.

There are several Clevo parts, that if you go to a Ford parts counter & referrence any car with a 351C in it, such as a 1970 to 1973 Mustang, you'll be given the wrong part, or you'll be told the part is obsolete. But if you reference a later car with a 400 in it, say a 1979 LTD for instance, you'll get the correct part, still available. I have read this is true of t-stats, but have never verified this. I also know it is true of the flat timing chain cover plate.

I don't blame you for finding it hard to believe that a vendor you respect would make this mistake, I don't blame you for finding it hard to trust some stranger on the internet (me). But I posted the pictures for you, you can see with your own eyes, the Clevo t-stat must seal against the orifice below it & seal it off. The t-stat you were sold is not capable of doing so. This will lead to overheating problems if the vehicle is used for high speed driving, on hot days, on long grades, in stop & go traffic, etc.

If you block that orifice, as has been the solution for many Pantera owners, you WILL develope steam in the heads when the motor is cold & the t-stat is closed. Which is then why owners find it necessary to drill holes in the t-stats, to allow the steam bubbles to pass. They've been told it is air.

So you see, one wrong part leads to one modification, which leads to another, which leads to another..... The Cleveland motor's cooling system worked just fine as delivered from the factory. (The Pantera's half of the cooling system was a bad engineering job however).

Like I wrote earlier, this is a problem that is as old as the motor itself. I have dealt with this problem as a part time mechanic dozens of times in the '70s & '80s, when the correct part was readily available. I became involved with Cleveland owners on the internet in 2001, on a different forum. Since then I have continued to run across this situation.

If the radiator, water pump & belts are in good shape & a Cleveland is having cooling system problems, there are 3 things to look for. A windsor t-stat, a Weiand water pump, or head gaskets installed improperly.

I have shared the info with you guys, a new wave of Clevo owners, now it's your turn to carry the torch.

Your friend on the DTBB, George
quote:
Originally posted by jwr2968:
Thanks George,I'm going to call Steve and talk to him about this.Maybe there is a simple explaination.Come to think of it, the origional one I pulled out also looked the same.I will check it out and let you all know.Thanks!


If the original looks like the one you sent, then maybe ol' Steve is more clever than we all think and knows that you have an aftermarket water pump.

Certain aftermarket waterpumps, Weiand???? for example, take a non-Cleveland thermostat. All of the discussion assumes that you have a stock cooling system and stock components, more or less...
Talked to Steve Wilkerson yesterday and he told me he only sells Cleveland thermostst.He gets his from Italy,and assures me it was correct. Mine had the spring showing like the winsor thermo but that it was the Cleveland.He said he had plenty in stock.What do I know.I am going to try to fax him a picture of the two thermostats.
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