How hot can you really run a flathead safely?

G.M. I think we are now at the point that we respectfully agree to disagree. You have finally addressed the original question of how hot can the flathead be run safely. My opinion is that there is no need to be alarmed if the temperature gauge reads H as long as the water is not boiling out. Your opinion appears to be that we should be alarmed if the temperature gauge reads higher than "normal" which, I assume, is the middle position on the gauge. I believe that Ford adequately refined the flathead engine, including the cooling system, over it's many years of production that it is quite sufficient as Ford made it as long as it is clean and operating as designed. You have found the original stock design inadequate in many respects and have put your effort into "tweaking" it to improve it which I find unecessary. I think that now that our two positions on this issue is clear we can let it rest and leave the other readers to make up their own mind. I have read opinions from others consistent with yours and others that are more consistent with mine.

It's been a pleasure (I think). :rolleyes:
 
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donald1950 said:
boiling point of water at 500 ft is 211 degrees

boiling point of water at 4000 ft is 205 degrees

altitude will make a difference, not alot, but there is a difference.....

for the guys at higher elevations, water will boil sooner.

here is a calculator: http://www.csgnetwork.com/h2oboilcalc.html
Click to expand...

But, keep in mind that a 4# pressure radiator cap will increase the boiling temperature about 12 degrees (a little more at low altitudes, a little less at higher ones) so us at 4000 feet don't really have to get worried until the temperature is approaching 222 deg. That's why the whole discussion about pressure and boilng points - to relieve anxiety caused by seeing the gauge on H. :)

Here's the chart that shows the differences in boiling temperatures at various pressures: http://www.engineeringtoolbox.com/boiling-point-water-d_926.html
 
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Are you saying that the opening in a modern t/stat is too small ,I thought I might try some on my 33.
Lawrie
 
Lawrie said:
Are you saying that the opening in a modern t/stat is too small ,I thought I might try some on my 33.
Lawrie
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If you're asking me I say no they are not too small. They were big enough for Mr. Ford and have always been big enough for me. If you're asking someone else they may say yes they are too small and only Gagiteer's is big enough. :rolleyes:
 
i used 180 Stant brand thermostats ( same onnes that i used in 8BA housings and chevy housings) when i had the 59A motor in my 41 PU. just ground the outer circurmferance down so they fit tightly in the hoses. never moved and the only time it got hot was when sitting in traffic, then cooled right away above 20 mph. better than no stats..... don
 
I use and like the high volume thermostats but I also run 13 pound radiator caps on both my av8's which some say don't and three blade fans. I'm not worried if mine was to get up to 215º or higher as long as there is enough pressure to keep the water from boiling. The problem with high pressure in the system is the cooling (shrinking) and heating (expansion) of the water causing the radiators with big top tanks to flex with each cycle which eventually weaken the tank and cracks start. The new ceramic water pump seals on our pumps now are much better than Henry had and I would guess he would have used them also if they had been available, then he could run higher pressure in the radiators. 13# in a large tank, probably not a good idea. Now this is my way but others I'm sure say I'm wrong, I can live with what they say and respect their opinion.

.125" overbore 8ba's

Vergil
 
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