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351C overheat...Help!!!

46K views 40 replies 22 participants last post by  HankFord 
#1 ·
Hi Everyone...I have an overheat problem that has aggravated me for years and stumped many experts.....I have a 4V 351C in a 65 fast back...that never would go over 160 deg on even a 100 deg day. I had the eng completely rebiult and bored0.030 over. Ever since this rebuild, the egine will over heat when idling, making intown driving nearly impossible. This occurs even on cooler fall days. Ihave tried every possible item anyone could think of...heres the list of changes / tests done
-the obvious....water pump, tstat, recorred rad(to a better type than original) and had retested by a 2nd shop...electric fans
-head gaskets 3 different makes
-electronic ignition
-replaced cam
-degreed in the cam
-removed eng and completely torn down and all clearances/tolerances checked by a 2nd eng builder
It makes me want to cry when i realize how much mondy i've sunk into this annoying problem..the eng was rebuilt in 1990!!
Note...it has a very high lift 580", long duration, solid lifter motorsport cam
Anyones help would be much appreciated. If you find the problem, I ll let you borrow it next summer! The car is a clone to a 66 shelby. Thanks
 
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#2 ·
Clevelands among other late model Fords are notoriously thin walled. Ford was very proud of their thinwalled casting technique . The .030" overbore may have been enough to cause the overheating problem. I'll bet if you were to sonic test the bores you would not be a happy camper at the end of the day. I'd put money on it that theyre under .100" in large areas.

If you are running electric fans only then you are in the process of discovering what most users of electric fans eventually admit or refuse to admit to themselves...They dont cool the engine very well. They'll cool late model 6 cylinders OK and low HP V8's but wer'e not talking about those. An electric fan in front of the radiator will disrupt airflow through the radiator . If its in the rear then your not using a belt driven fan and a big belt driven flex fan will pull a LOT more air than any electric despite any marketing claims to the contrary . More air = cooler engine even if it takes 12 HP to do it and if so then so be it. And above all else use a shroud !

Been there on both counts.

_________________
438" Dart Windsor, AFR 225 heads, 271/279@.050" on 106 solid roller, 13:1 compression, Super Victor, crank trigger, 950 HP , external oiling, reverse manual C4, 4000 stall, 4.10 Dana 60, Nitrous. Street '68 Cougar. 9.967 at 134 MPH! 1.44 60 ft

<font size=-1>[ This Message was edited by: mikeandnatasha on 8/18/06 10:06am ]</font>
 
#3 ·
Thanks for the detailed reply, Mike. I had also gone the eng driven fan route (numerous shrouds, different spacers-getting fan closer to rad) to no avail....the nice part, though about the electrics is that i can leave them on to get the temp down with the engine off. This probblem to me seems unusual...as it just doesnt run hot, but if i hit two red lights in a row on even a cool night (say 60-70 deg) the temp just keeps climbing well over 200, in one case i had to keep it running (stuck in traffic) and it hit 220...after 200 the engine doesnt run worth a damn.....I have heard about thin wall issues...but the hard part to swallow is that before i rebuilt it , i had idled the car for an hour in 100 degree heat and it never moved off 170 !! Your help and time is well appreciated, thanks
 
#4 ·
Do you have a water metering orfice under the waterneck/ thermostat to keep the hot water from recirculating ? I bought a 351c ranchero with a new radiator that ran quite hot and when I checked for the metering plate it was gone. I replaced it and all colling problems were gone.
 
#5 ·
Yeah . What he said ! I forgot about that metering orifice . If thats not there it will run hot all the time. You know that water neck thing is the greatest thing about the cleveland and the 385 series IMHO. pull the manifold...no water.
 
#6 ·
15-16 years is a long time to live with this sort of problem,if you have done absolutely everything id also be looking at the block,
might be worth pulling it again and having it sonic tested as mentioned above.
im waiting to see if youve got the metering orifice covered also,but if thats not your problem the block is where i think id be looking next.
 
#8 ·
After all yo've been through I am going to side with the THIN Cyl walls people.... That was my first thought after seeing what you had gone through...

Sometimes you get a "Friday/Monday" engine and sometimes you get a "Wednesday" engine... You got a Friday/Monday engine....


FE
 
#9 ·
I had a Boss 351 block that I was having the same problems with. . Bored it .030" over and it got hot afterwards and had a terrible blowby problem. I puilled it apart and rehoned it , changed rings etc, looked for cracks or whatever and put it back together. Same thing. Then I pulled it apart AGAIN and borrowed a sonic tester from my dad who is a NDT engineer. It had cylinder walls as thin as .088" with HORRIBLE core shift . I scrapped the block and pulled the 4 bolt main caps and had them installed on a 71 2 bolt block that I verified the cores before I had bored and they were in the .130" range after the bore job. Problems went away. Not saying thats his problem but its a problem that is common to Clevelands, 302's and FE's. Early 351 windsors, reverse 105 FE's and 460's seem to have been spared the thinwalled demons probably because of their truck status but you have to suspect any Ford block . I mean it. For was proud of their thinwalled casting technique and spent a lot of money and time developing it.

That does bring up a good point. If you need to swap block the early cleveland blocks are cast with the 4 bolt nubs and dont require any machie work other than a line hone and drilling and tapping of the outboard holes.

http://users.adelphia.net/~mikeandnatasha/C1.jpg
http://users.adelphia.net/~mikeandnatasha/C2.jpg
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_________________
438" Dart Windsor, AFR 225 heads, 271/279@.050" on 106 solid roller, 13:1 compression, Super Victor, crank trigger, 950 HP , external oiling, reverse manual C4, 4000 stall, 4.10 Dana 60, Nitrous. Street '68 Cougar. 9.967 at 134 MPH! 1.44 60 ft



<font size=-1>[ This Message was edited by: mikeandnatasha on 8/19/06 12:25am ]</font>
 
#10 ·
I am thinking possibly the water is not spending enough time in the motor. If you flow water in and out of the motor to fast it will not be able to pickup any heat. Been 35 yrs since i messed witha cleveland. But i think as mentioned thre is a restrictor in the neck.
 
#11 ·
I have a .030 over cleveland in an early coupeand I had a cooling problem but not as severe as you are having (no problems below 70 for my car). Most likely "thin walls" is the problem. If you haven't done so already and haven't given up you can open up the opening in the radiator support and go to a "wider" radiator and try an oil cooler. More surface area (for the radiator) is better than "thicker". My engine would run pretty cool (for about 10 miles) until the oil temp came up so th eoil cooler helped. The lower valence (below the bumper) blocks a lot of air, I would open that up too.
 
#12 ·
The thing in the block isnt a restrictor. It diverts flow to the rear of the engine so that the rest of the engine gets water instead of just the front which is what happens if its not there. Sort of like if an FE cyl head gasket gets put on backwards.
 
#13 ·
Well, as a brand new member here, these many respones are very impressive! a big thank you to you all!
It s nice to see such a close knit ford family!
However, today, my heart sunk to my feet....a rattle last night became increasingly louder this am... i believe a bearing has let go ..... i will likely be pulling the eng next week.... thanks again for all your input
 
#17 ·
Thin walls has nothing to do with it.
Look at the restrictor under the T stat housing, if its not there, or is damaged, then the water does'nt circulate correctly.
Also, the size of the radiator is a factor too. If its too small, it will run hot.
What about the fuel mixture?? if its too lean, you'll run hot. Are the head gaskets on backwards??.
Check all these things....go thru the process of elimination.
 
#20 ·
I know you said that you have checked the thermostat. But it must be a cleveland specific thermostat. If you use a thermostat for a 302/351W then it will overheat. The cleveland specific thermostat seals off against the restrictor in the block. This restrictor is used to force some of the coolant to bypass the radiator and recirculate through the block for quicker warmup. Once the thermostat opens up the bypass is blocked off and all the coolant is circulated thru the radiator. What is your coolant/water mix ratio? This too can have a major effect.

Good luck, Tom
 
#22 ·
Thanks Tom, thats the first time i have ever heard of a cleveland specific thermostat. if that is the cause of the uncontrollable overheat, it is a wonder that it isn't more common knowledge that it can overheat that easily by using the wrong one....I'll let you know the results! thanks again
 
#24 ·
Sorry to hear but my moneys on the head gaskets where put on back wards when it was rebuilt cleveland have front stamped on the gasket when put on backwards you ll never stop them over heating it most likely got hot and the oil lost viscosity and thats why its run a bearing either that or the heat caused it to detonate and its lost the top off a piston.
 
#25 ·
if its not head gaskets when you pull it apart try running a bypass line from the block to the top of the thermostat housing i build alot of clevos from street to race and never have any problems with overheating i put one on a friends street clevo which would always overheat and now we have trouble getting it up to temp have to leave fans off even in summer hope this helps if your not sure what i mean i can email you some pic s of the bypass set up
 
#26 ·
Some Cleveland owners are using the reverse flow method of cooling the engine. This method diverts the flow thu the cylinder heads first. Everone has mentioned the thin wall problem. I fill the block to the freeze plug holes to give the cylinders some additional support. This is alos used to increase flow to the top end of the block where the temps are much higher.

Also, make sure the radiator is not filled with debris. Many times the top sections will flow fine, however the lower portions are clogged with rust and scale that have been flushed from the cylinder block. Scan the radiator with a infa-red temp gun ( $49 @ Pep Boy's) to verify that the temps are even from top to bottom. Also look for temp. drops acrossed the radiator core. Adding some of the "water-wetter" poducts. Some guy's claim 20 degree drop in operating temps.

Finally, what your ooil temps! if you do alot of steet driving, you may consider an oil cooler. Engine oil is not just a lubricator, it also cools the internal engine parts.
 
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