Hot engine

[jwhite1149]

How hot can a flathead get before it will lock up?

[1967gt]

Wtf ? Come on

[ford3]

when racing them ive seen then go to around 260 before locking up

[my4dv8]

Are you going to test one for us?

[Barry-ct]

Wouldn't you rather know how to keep it cool so it doesn't lock up?

[ford38v8]

Sponsored Links (Register now to hide all advertisements)

This Forum is known to be civil, friendly, and helpful.
The guy asked a legitimate question and deserves a legitimate friendly answer.
Sarcastic remarks are not helpful, nor do they encourage future questions.
Do we really want to get like that other Forum?

[1967gt]

Was that an aswer to the question ?

[Bluebell]

Here's my take on the question:
It depends entirely how much piston to bore clearance you have. and the expansion rate off the alloy in the pistons. Do you mean due to heat or the lack of oil?
Heat wise,
A worn motor will go longer than a new tight one.
No one would have done tests for this.
If you have solid skirt pistons or split skirt pistons changes it.
Many things will come into it.
Racing clearances are much bigger than street clearances.
Engines are built for specific applications. The flathead was first built for a no pressure cooling system, which means she boils at 212 degrees at sea level.
If you want one to run at 260 degrees with a 14 pound pressure cooling system then you would adjust you assembly tolerences to suit.
It is hard to answer your question. It is about as vague as trying to say "how long will it go before locking up" Depending on the surrounding circumstances, a long time, or no time at all.
With a lack of oil it changes. Here the rings will likely grab first, no load, idling a long time. Under load,high revs, about 1 turn of the crank.

Here is an example of a sort;
My son in law works for a firm that hires generators. (diesel)
They don't sell them, they scrap them, when they are finished with them.
They removed the radiator, and dropped the oil from the sump of one a couple of weeks ago and left it idling. Apparently it idled for a couple of hours. Not bad I thought.
Does that help?

[Lanny]

It's kinda like asking, How long is a string


Bluebells answer pretty much sums it up, and he answered
the question about as good as it could be answered.











.

[Bluebell]

Sorry Lanny I obviously edited my post while you were posting. Yours was there straight away after I submitted. Thanks for your comment.

You just made my day!

[BILL WZOREK]

jwhite1146:

I don't have a answer but I feel Bluebell Had a very good explanation.
Now my Question to you WHY the Question what part of the problem are we missing??

[jwhite1149]

You guys are over thinking my question. My 37 pu has an overheating problem. I've done all the things recommended on The Ford Barn but, was thinking.........how hot can this flathead get. I have a distributor coming from Bubba's, have done the flush, so on and so on. I do not want to damage my engine, so the question... Do I shut it down at less than 200, 210 or 220??? What is my upper limit, where is the point of real danger? Sorry, I thought it was a fair question. Guess I was wrong. Jim

[4tford]

Not to worry Jim, I think there was not enough info in the first question and the way you rephrased it will get better responses. Ignore the rude answers as they usually come from new comers who think this is the same as the hamb. They do not usually stay here long. JMO

[Kahuna]

Jim
My rule was to shut the engine down at 230 degrees and let it cool.
When I had a heating problem on my 39, at that temp the radiator hose(s)
would usually blow off.
You asked a fair question, in my opinion

[rotorwrench]

Many old originals just have an "H" mark at the top of the indicator scale. That's hot enough for me. The hotter they get, the quicker they get hot. They may seize but then free up after they cool down. Then the big question is how many cracks will they now have around the exhaust valve pockets after this happens? This will guarantee it gets hot all the time, especially if coolant starts to leak into the cylinders.

An engine that gets much above the thermostat temp under normal flat land driving conditions generally still has some other probelms lurking down inside. Radiator may need rodding out. It may already have a crack in the deck or in a valve pocket somewhere or maybe thin cylinder walls with deep pitting. Could be little or could be not so little.

[ford3]

Jim, 40tford is right, there are always a few pr**ks on every forum, go back and read the responses and you will see who they are

[jwhite1149]

ford3, Thanks, you are right. To all others thanks for the info.

[Mike in AZ]

yep, i guess it depends on the engine, etc. as others have said.....yours might lock up at 220 and when cooled down, start up and be fine, etc.....what high temps are you seeing??....and does running it help to cool it down rather than idling it??....or does fast idling help to cool it or does temp keep rising??....good luck and hopefully the distributor is the whole solution or at least part of the solution.....Mike

[my4dv8]

Sorry j white my apologies read a further post from you and now understand what you mean , what is the danger zone . Seems like a few others have chiped in with good responses. Good luck.

[Ol' Ron]

Our stock car would come in after a race around 230/240. It had a 4 core Chrysler radiator and 14 lb cap. Pistons were the cheep Jans set at .006"
Recently the 294 over heated (7lb) got up to 230. with Ross Pistons set at .004" Engine runs fine today. Takes awhile to worr the bugs out. I hope I never see 260 degs in any water cooled engine.