Well, my cooling saga continues. The truck is a 78 F-150 400 bored 30 over @300 hp. I have around 300 miles on the engine
Things that I have replaced with NEW items
Radiator
Flowkooler High flow water pump
Fan
Fan Clutch
Hoses
T-stat
Electric Fan mounted in front of the radiator

The truck will run normal temp for 5 or so miles then it runs all the way on H. I bought a VDO water temp gauge and I hope to install it tomorrow. I know the stock gauge is close because when it gets hot and I pop the hood I can feel the heat coming off the engine.

* Any thing else it could be?
I have played with the timing a bit and it does not seem to make any difference.

Any ideas/suggestions would be greatly appreciated

Thanks as always,

Nik

 

Nik,
Its very hard to tell with all the `new` stuff.
did you install a 3 tube or 4 tube Raditator? It really should not matter!! do you have a Catch can? and is there water that is being blown into it? Now I mean not just flowing in to it BUT Blowing in to it like you have a head gasket that is giving you a problem.??
My Engine takes about 10-15 min to come up to Operating temp (170-180deg) in the morning.
If you are seeing the water expand before it should then there is a problem. Fill the rad dead full when it is cold. like in the morning. My over flow can sees about a pint/or two of fluid between when it is cold and running at temp.
You should `see` NO fluid flow to the rad before the Thermostat opens. How long does it take ?
Be careful of hot fluid flow if you have the cap OF!!!Even High Flow pumps will not send fluid to the rad till the stat opens!! If you are over heating AFTER the stat opens then maby it is the flow rate through the Raditator.. Like the tubes are too small to handle it (just guessing now)..

Ok I have drilled a small hole(.100) in the thermostat flange to let a small amount of water and TRAPPED air to pass. Old trich to help where the Thermostat and hoses are ABOVE the tank of the Rad (height problem).

NOW have you Preasure checked the system? Do it COLD in the morning!! will it hole 15 lbs for a period of time like 10 min? or longer? How long will it hold the preasure?
Iam not sure about youe gasket configeration Intake etc..
Could you be blowing Exhaust Gass into the coolant!!?? Air/gass will go to the top of the engine Temp Sensor area and the sensor will not see any Fluid to get a good reading!!
Ok Iam out of ideas to look at....



__JOHN__Õ¿ö
72 F-250
ICQ#6030753
http://clubs.excite.com/72FORD-F-250

 

The stock radiator (3 row) didn't look bad but I replaced it anyway. The new radiator is another 3 row. I would think that a three row would run a little warmer than a 4 row, but it still shouldn't overheat like it does.

I don't think it is a head gasket because I do not have any water in my oil.
Is there another way to check for a blown head gasket?
The engine runs great until it starts to get hot.

 

The preasure check COLD(leak down test) should check for a bad head gasket!!

By the way Is your Fan Just at the edge of the shroud or in about 1 " ..
It should be IN about 1 to 1-1/2 inch past the edge of the shroud...


__JOHN__Õ¿ö
72 F-250
ICQ#6030753
http://clubs.excite.com/72FORD-F-250

 

The only other thing I can think of to make sure of, is no small task. I'm in the process of building my 400 also, and have been warned by several people to make absolutely positively sure that the head gaskets line up correct and are on the right way, otherwise you block off some coolant passages to/from the heads. Guess checking it out could be a last resort.

Matt

 

Could the high flow water pump be pumping the coolant to fast so it doesn't have time to dissapate heat?
I've never heard of this before but at this point I'll try anything.

Nik

 

Yes.... It has the same effect as running without a thermostat. the flow through is higher than can be handled by the cooling capacity of the radiator.

__JOHN__Õ¿ö
72 F-250
ICQ#6030753
http://clubs.excite.com/72FORD-F-250

 

did you put the thermostat in backwards? copper looking thing goes into the engine side

 

No, the t-stat is in the right way. I am in the process of presure testing the system right now. I should pump it to around 10-12?

 

It should hold what your cap is rated at ...7,13lbs etc...

__JOHN__Õ¿ö
72 F-250
ICQ#6030753
http://clubs.excite.com/72FORD-F-250

 

I borowed a coolant pressure tester from Autozone
and the system held 13 pds. of pressure. I hope that rules out head gasket.

Well, hmmm .......

 

Nik, I think Matt may be on to something! Flipped head gaskets will indeed cause an overheating problem on a 400. After reading all these posts and looking at the list of new parts you have installed trying to solve this problem, my advice is "take your truck to the shop that installed your re-built engine and complain until they fix it"! This overheating problem started with the re-build on a 400.
William

 

If the head gasket is flipped, will it still hold pressure?

 

I just put my 400 heads on last night and now you guys have got me nervous. The gaskets are identical. You can get one to read FRONT face up and the other is installed FRONT face down. I hope mine is ok. Good luck.

Rich

 

Many companies make head gaskets, some are made “offshore” and may or may not be marked. Some head gaskets have metered orifices that regulate water flow, if these are installed incorrectly (flipped) the flow is cut off and will cause overheating. Flipped gaskets will hold pressure. It is possible to install head gaskets and other parts/assembles incorrectly. One of my favorite truisms says “if a part can be installed wrong there is a mechanic out there who will install it that way”. Go back to the beginning of this issue. Where did you get this engine? Who re-built it? Is it warranted? Nik you make your living with this truck, take the engine back and demand a replacement. The previous engine did not over heat, with a standard water pump, the old radiator, no shroud, same driver and so on…..The builder or the machine shop missed something. One more thing, check the exhaust manifold heat riser, make sure it is opening, and look at the exhaust pipe, maybe its pinched or obstructed? Is the fan pushing or pulling? Please let us all know what you decide!
William