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Discussion Starter #1
I've got a 73 XR7 w/ a fresh rebuilt 351C.

0.030 overbore
KB177 pistons - ~9.5 cr
comp 268h cam

For cooling -

Flowkooler hi-flow water pump
Factory 4-core radiator
16" 2200 cfm electric fan w/ shroud
180* t-stat

When the outside temp is under 80*, I don't have problems. It will hang at about 185-195* stop n go or otherwise.

When it's hot outside my temps (especially in stop n go) will creep up as high as 218*. I assume it could go higher, but I haven't seen it higher (yet)

My question -

Is this typical? Is 218* on the hot side, or is this ok?

Would an aluminum radiator help with the situation? I don't think its an issue with my fan's ability to draw the heat from the radiator. The radiator remains cool. I suspect heat transfer is my problem.

Of course I am probably just paranoid and this is totally normal.

What do you think?
 

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Go with this and your cleveland will live long and prosper.

Reproduction 351C Water Restriction Plate for the 1970, 1972 and 1973 Mercury Cougar and Ford Mustang


<table width="600"><tbody><tr valign="top"><td width="300"><center><table align="left"><tbody><tr><td align="center"></td></tr><tr><td><center>Click to enlarge</center></td></tr></tbody></table></center></td><td width="300"><table border="2" cellpadding="5"><tbody><tr><td><form id="yfc_1" method="post" action="https://order.store.yahoo.net/yhst-11089400041767/cgi-bin/wg-order?yhst-11089400041767+waterrestrictplate">Print This Page
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Availability:
Usually ships the next business day

Orderable?


Part #: 10003234

Price:$17.85



I Need to Order: <input name="vwquantity" value="1" maxlength="3" size="3" type="text">

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Description:
It has been an accepted fact for decades now that the 351 Cleveland bypass system was not the greatest idea Ford ever came up with. The unique 351c thermostat "hat" never seals well, causing a certain portion of coolant to just circulate through the block and never make it to the radiator. Years ago, the Pantera enthusiasts (all Panteras had cooling issues from the factory BTW) found that if they soldiered a penny into the hole in their restriction plate and used a standard small block Ford thermostat, their cooling issues all but disappeared. That trick worked fine until Ford discontinued the brass restrictor plate. This aluminum unit is designed to be installed as-is in conjunction with a standard thermostat , you cannot use the 351 Cleveland unique thermostat with this block off plate. The tiny hole in the center is for air bleed only. Want to find out how to use a penny instead of spending $17.85? Click hear to learn more!
 

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It's true. ^

Car should be able to maintain a steady temp as directed by the spring on the t-stat. You don't need a high flow pump or any of that, though it's fun to have.
 

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Discussion Starter #4
Thanks guys! Order placed. I'll let you know how it goes.
 

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Cool, i know where to buy these when i build my next motor.

thanks
pat
 

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Not sure what the difference is, but my block is .030" over, I am running a stout (and true, actual) 10:1 compression, stock pump and restrictor with Cleveland T-stat and have the block half-filled with Hard-Blok. New 4 row brass radiator. On a 100 degree day with the AC running I still do not go over 2/3rd's on the temp gauge.
 

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Discussion Starter #7
I am betting that when I purchased a high-flow thermostat, I didn't get the Cleveland specific one. The parts guy at Summit Racing just grabbed a ford one off the shelf. I should have paid closer attention. Switching to a Cleveland t-stat would probably solve my problem. I got the restrictor anyway, as it can only help.
 

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I am betting that when I purchased a high-flow thermostat, I didn't get the Cleveland specific one. The parts guy at Summit Racing just grabbed a ford one off the shelf. I should have paid closer attention. Switching to a Cleveland t-stat would probably solve my problem. I got the restrictor anyway, as it can only help.
Has happened many times before...
 

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I am betting that when I purchased a high-flow thermostat, I didn't get the Cleveland specific one. The parts guy at Summit Racing just grabbed a ford one off the shelf. I should have paid closer attention. Switching to a Cleveland t-stat would probably solve my problem. I got the restrictor anyway, as it can only help.
You must use the correct cleveland thermostat with the stock restrictor plate and the windsor thermostat with Don's modified plate. Aftermarket sending units are notorious for causing inaccurate gauge readings. An NOS sending unit and the correct Robertshaw 351C thermostat solved my problem on my 351C, .040" over, 11:1 compression, A/C equipped car.

Have you verified your temperatures with an infrared thermostat?
 

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Discussion Starter #10
I'm getting the readings from a mechanical autometer water temp gauge. I had switched to it as my factory gauge was always getting pegged. It seems normal on the factory gauge is about 180* and H is prob around 200* or so. It sounds like once I get the proper t-stat arrangement, I should be able to go back to the factory gauge as it should hang around normal. Looking forward to that!
 

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Look at replacing your sending unit for the ford gauge and maybe the assorted wiring needs to be looked at too. I much prefer the factory stuff to the aftermarket thermal gauge.
 

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Not sure what the difference is, but my block is .030" over, I am running a stout (and true, actual) 10:1 compression, stock pump and restrictor with Cleveland T-stat and have the block half-filled with Hard-Blok. New 4 row brass radiator. On a 100 degree day with the AC running I still do not go over 2/3rd's on the temp gauge.
Yeah, baby. Talk Cleveland to me!!!:buck:
 

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Discussion Starter #13
I dug out my old receipts and confirmed that I am not using the Cleveland thermostat. Once the new restrictor arrives, I'll be set.
 

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any of these issues apply to the 351W? i don't have a lot of faith in the stock temp gauge. i would prefer an actual temp in degrees. is the stock sending unit, thermostat and gauge good enough or is there a better, more reliable system?
 

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What year is your 351w? Believe it or not it makes a difference. Most vendors sell a one size fits all and that will often give you a false reading. The 351w does not have the same issues as the 351c and the factory gauge is pretty darn reliable.
hey Don - it's a 1970 Mercury Cougar with a 351W. 4 bbl Edelbrock intake and carb
 

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Discussion Starter #20
Thanks guys, I installed the restrictor and my temps are much more stable.

I'm going back to the factory gauge - as such I'll replace my sender with a known proper one from wccc. Does anyone know what temp is the normal range on the factory gauge (73 cougar)? High?
 
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