I've heard the flathead described as an "eternal engine" because it's geometry allows the replacement of sleeves and valve guides. Can you really run a flathead as long as your willing to rebuild it, or does the block warp after a certain number of rebuilds? I've daily drive classic cars before and I'm interested in a flathead for my next ride, so please fill me in!
Flathead Longevity
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JSeery
Member Emeritus
Most rebuilds do not get sleeves unless there is a problem to correct. IF you did use sleeves and replace the sleeves as needed the block sees little to no impact during a rebuild. Ford 8N tractors work this way and the engines should, as you say, last forever.
Even without sleeving you can overbore a flathead many times. With each rebuild you are going to get a lot of miles out of it with reasonable care. Boring a flathead block is not going to lead to a block warping.
Even without sleeving you can overbore a flathead many times. With each rebuild you are going to get a lot of miles out of it with reasonable care. Boring a flathead block is not going to lead to a block warping.
Ralph Moore
Well-known member
Flatheads Forever!
Scott H in Wheaton
Well-known member
I would guess most flahead engines will long outlive their owner.
JSeery
Member Emeritus
And most likely the next several owners!
Shadetree
Well-known member
The only weakness I know that the flathead has is overheating. I ruined a perfect `40 engine back in the mid 50's. A careless teenager didn't see the heat gauge in time.
I have heard you can run the engine wide open without a load and the valves will float before it comes apart.
I have heard you can run the engine wide open without a load and the valves will float before it comes apart.
Bubsyouruncle
Senior Member
The Ford flathead was designed by good engineers paid by a demanding boss who was determined to get the most out of the investment in time and material.
Given proper care and reasonable demands a flathead may well see service on the moon.
Will an SBC?
Given proper care and reasonable demands a flathead may well see service on the moon.
Will an SBC?
Admiral
Well-known member
When asked if driving on the highway was too stressful for the engine in my ‘36 sedan, John Miller, my engine builder and loooooong time flathead V8 enthusiast said, “Don’t worry, just drive it.”
When asked if a Columbia or similar OD was a good idea he said, “Don’t worry, just drive it.”
When asked about oil viscosity and change intervals, valve adjustments, carburetor rebuilds and the like he said, “Don’t worry, just drive it.”
My take on all of this is that Henry’s venerable side-valve V8 is pretty much unbreakable in stock form so long as you take reasonable care of it and don’t allow it to overheat. Mine routinely sees 4,000 RPM and sounds sweet all the while. Do I ever worry about sending a rod through the block or blowing the bottom end out? No, not really. If something ever did happen out on the road I can probably fix it with a crescent wrench and some bailing wire.
I think a lot of folks are far too easy on these machines (though it is understandable if you just spend six figures and a decade’s worth of time restoring a 1,000-point car); they were designed to give years of trouble-free service under the most trying conditions. My 59L block was already hogged out 0.060 when I got it and John took it another 0.020, so it's probably been rebuilt, what, at least four times? Like him, I say, “Just drive ‘em.”
When asked if a Columbia or similar OD was a good idea he said, “Don’t worry, just drive it.”
When asked about oil viscosity and change intervals, valve adjustments, carburetor rebuilds and the like he said, “Don’t worry, just drive it.”
My take on all of this is that Henry’s venerable side-valve V8 is pretty much unbreakable in stock form so long as you take reasonable care of it and don’t allow it to overheat. Mine routinely sees 4,000 RPM and sounds sweet all the while. Do I ever worry about sending a rod through the block or blowing the bottom end out? No, not really. If something ever did happen out on the road I can probably fix it with a crescent wrench and some bailing wire.
I think a lot of folks are far too easy on these machines (though it is understandable if you just spend six figures and a decade’s worth of time restoring a 1,000-point car); they were designed to give years of trouble-free service under the most trying conditions. My 59L block was already hogged out 0.060 when I got it and John took it another 0.020, so it's probably been rebuilt, what, at least four times? Like him, I say, “Just drive ‘em.”
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The block doesn't warp after so many rebuilds. Also it's been said that the cranks can only stand a couple of grinds before the hardens is cut through, this is also a steaming pile of toss! The crank will go as far as you can get bearings. The big journal cranks can even go to small journal size then it's undersized bearings if you needed too.
The saying "Flatheads Forever" is true. Not regarding the terminal cracks that can effect any engine.
Don't worry, just drive it.
Martin.
The saying "Flatheads Forever" is true. Not regarding the terminal cracks that can effect any engine.
Don't worry, just drive it.
Martin.
earlyride
Senior Member
Love my flathead and love my SBC also, it's in my suburban and has over 334,000 original miles without a rebuild, so yes they too may well see service on the moon