Engine failure after 20000 km.

[Vicus]

So I guess you have ditched the 4 speed top loader idea then.

Not yet, Geoff, but I have to postpone the project until I'm allowed to retire. Then I will have more time at my disposal. It wasn't planned that the engine would break down before then, but as they say: things usually turn out differently thank you think.

 

[cjstaci]

50+ year old push rods could be a victim of metal fatigue, or excessive clearance due to a collapsed lifter or flattened cam lobe, loose or damaged rocker arm, weak or broken valve springs, any of which could be suspect.
Now is the time to bump your engine performance up, switch to closed chamber heads, hardened push rods. Guide plates and adjustable rockers. Probably aftermarket aluminum heads would be best for the money.
As long as everything is in good working order, you shouldn’t have any problem cruising on the autobahn at between 3000-5000 rpm. The drawback is of course more fuel consumption and more engine wear.
When I was in Germany, I had a Capri with a V4. I was driving from Kaiserslautern to Frankfort and running about 7000 rpm. That was about a 90-100 mph and people were passing me all the time. The pinion seal failed and fried the rear end. The car was towed to an impound lot. I had to come back, find a rear end in a salvage yard and then swap the rear end. Quite an ordeal.
I remember the speed limit in city areas was 100kph but unrestricted out of cities. If I were there, I would want the car to handle the autobahn speeds safely and easily.

 

[giantpune]

50+ year old push rods could be a victim of metal fatigue, or excessive clearance due to a collapsed lifter or flattened cam lobe, loose or damaged rocker arm, weak or broken valve springs, any of which could be suspect.
Now is the time to bump your engine performance up, switch to closed chamber heads, hardened push rods. Guide plates and adjustable rockers. Probably aftermarket aluminum heads would be best for the money.
As long as everything is in good working order, you shouldn’t have any problem cruising on the autobahn at between 3000-5000 rpm. The drawback is of course more fuel consumption and more engine wear.
When I was in Germany, I had a Capri with a V4. I was driving from Kaiserslautern to Frankfort and running about 7000 rpm. That was about a 90-100 mph and people were passing me all the time. The pinion seal failed and fried the rear end. The car was towed to an impound lot. I had to come back, find a rear end in a salvage yard and then swap the rear end. Quite an ordeal.
I remember the speed limit in city areas was 100kph but unrestricted out of cities. If I were there, I would want the car to handle the autobahn speeds safely and easily.

I think OP has discovered the downside to more engine wear. Things wear until they break.

 

[cjstaci]

I think OP has discovered the downside to more engine wear. Things wear until they break.

Wait a minute, you mean parts break when they wear out, that’s just crazy talk, lol.
I think ford should repair it under warranty, after all, it’s only been 50+ years.

 

[AcesArneson]

I should really think about an OD gearbox, whether AOD transmission or Gearvendors OD. However, the 2.75:1 rear axle reduces the revs by ~15% compared to the currently installed 3.25:1. That is immense.

Keep it as simple as you can. If you are looking for an easier time keeping up on the freeway then do an AOD or 4R70W swap. Lots of guys on this site (including myself) have done this. The end benefit is you have the same car with a bit more top speed that costs you less gas.
I don't subscribe to the 'you got to leave it as it is or it's not a classic' theory. If you want to restore your car to concours level then be my guest but if you just want to enjoy your classic, make it your own.

 

[Vicus]

Thank you all very much for your diverse opinions. Nobody expects everyone to have the same opinion.
First of all, I would like to mention that I am not part of the restomod movement. I chose a classic car, in this case a 72 Mach1, in its original state, because I like driving a car with this historic technology. I don't want to change it fundamentally, because I believe that the overall design and technique best reflects the technical achievements of the engineers of the time. On the other hand, the old technology also needs to come closer to today's habits.
For this, I prefer a well-maintained classic car that still works reliably today with the technology of the time.
I don't need a Coyote engine under the hood, digital instruments in the dashboard or 18" wheels in the wheel arches. Nor do I need a modern chassis or rack-and-pinion steering or an air-ride. My car brakes very reliably even with 4 drum brakes without a brake booster.
In return, I accept the installation of an electronic ignition system like the Pertronix, a home-made exhaust system with manifolds, and soon also aluminum heads. A Holley 4160 is already working reliably under the original air filter box. On the whole, my car will hardly show any change from the classic appearance on the outside, but it should work reliably. My car will spend most of its future automotive life on the back roads of its new home in southern Germany. The roads here are winding and it's more about torque than top speed. I try the 2.75:1 differential first, because it's already on the shelf and doesn't require any additional investment at the moment. 60 mph at less than 2500 rpm is much more pleasant, both for the engine and for my ears.
And if I do have to hit the highway, I just have to control myself and put my right foot less heavily on the gas pedal. At least from today's perspective, this seems feasible.

 

[Sheriff41]

Thank you all very much for your diverse opinions. Nobody expects everyone to have the same opinion.
First of all, I would like to mention that I am not part of the restomod movement. I chose a classic car, in this case a 72 Mach1, in its original state, because I like driving a car with this historic technology. I don't want to change it fundamentally, because I believe that the overall design and technique best reflects the technical achievements of the engineers of the time. On the other hand, the old technology also needs to come closer to today's habits.
For this, I prefer a well-maintained classic car that still works reliably today with the technology of the time.
I don't need a Coyote engine under the hood, digital instruments in the dashboard or 18" wheels in the wheel arches. Nor do I need a modern chassis or rack-and-pinion steering or an air-ride. My car brakes very reliably even with 4 drum brakes without a brake booster.
In return, I accept the installation of an electronic ignition system like the Pertronix, a home-made exhaust system with manifolds, and soon also aluminum heads. A Holley 4160 is already working reliably under the original air filter box. On the whole, my car will hardly show any change from the classic appearance on the outside, but it should work reliably. My car will spend most of its future automotive life on the back roads of its new home in southern Germany. The roads here are winding and it's more about torque than top speed. I try the 2.75:1 differential first, because it's already on the shelf and doesn't require any additional investment at the moment. 60 mph at less than 2500 rpm is much more pleasant, both for the engine and for my ears.
And if I do have to hit the highway, I just have to control myself and put my right foot less heavily on the gas pedal. At least from today's perspective, this seems feasible.

Can't argue with that. Driving a classic car in its as-designed configuration is a great way to appreciate our hobby. Best of luck on your rebuild and let us know how it goes!