My Engine replacement odyssey - 1994 HR
My engine replacement odyssey has begun. I posted questions about the 460 V8 in my 1994 Holiday Rambler some time back and after much engine diagnosis and finally laboratory analysis of my crankcase o...
Forum Discussion
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Great project, Steve. Thanks for taking time to document it on the net.
I can take a guess what caused the original engine to fail after so few miles. The Ford big block is known to be very durable, having even larger bearings than the GM 454.
My guess would be the 460 aluminum timing cover corroded through because the anti-freeze was not changed out often enough, certainly not every three years as required. The PO probably figured that the low miles excepted this vital service.
What happens when the coolant is not changed is that the coolant often becomes acidic and the 460 is notorious for the timing cover corroding, as it is the rear water-pump wall separating the coolant from the crankcase (timing chain). Water in the oil severely damages bearings, leading to excess wear. Glycol anti-freeze is said to accelerate the damage.
The clues are the damaged heater core, the necessity of radiator replacement and, if they weren't sure where the leak was coming from, swapping out cylinder heads with suspected head gasket leaks. The heads may have been earlier, thicker castings and even older ('69, '70) small chamber high compression heads which were once deemed desirable for power and fuel economy. Radiators do not corrode so easily from the outside as they do internally.
Also regarding swapped heads, there does also seem to be a problem with engines that have been parked for long periods, not properly moth-balled and not run much. Idle motorhomes come to mind. Cylinder walls rust and gum up the rings as they scrape clean, causing rings to stick in their lands and ruin compression. In addition, this scenario often seems to wear out valve guides at lower mileage as though the stems may also have rusted from sitting and slow condensation. The rough stem surface then may gall the guides. In some cases valves will actually stick on engines sitting idle for years, and one might therefore suppose that all neglected valves may suffer some lesser corrosion. I imagine it to be similar to little-used disc brakes that tend to gather surface rust, a more common observation. This is only reasoned conjecture on my part, however. But regarding the possibilty, it does warrant starting, driving and thoroughly warming engines periodically, perhaps weekly, to recoat them with protective oil film.
One of my first engine overhauls was also the Ford T-bird 312 Police Intercepter V8. It was in a 1957 Fairlane 500 that I got for $200 when it was only 7 years old. Unfortunately I was changing out the non-detergent break-in oil on a twin cylinder, pneumatic, axle-lifting, truck hoist when the car met it's demise.
It was graduation weekend and I was looking forward to hot-rodding it after babying it for the first 500 miles. Near quitting time, I was still working at the service station and my buddy was eager to help while I was busy. The long-wheelbase, double floor-cylinder truck hoist could safely be used to lift these old cars by their bumpers, leaving our auto frame-hoist free for customers.
The SNAFU was that my buddy began letting the car down one cylinder at a time instead of carefully lowering both simultaneously. Lowering the rear only, the front bumper stretched right off the forward axle cradle and dumped the car off the hoist on it's side. Needless to say, I was wasn't pleased. But thank God no one was hurt.
Good luck with your adventures and watch out for falling vehicles.
Wes
...
Great project, Steve. Thanks for taking time to document it on the net.
I can take a guess what caused the original engine to fail after so few miles. The Ford big block is known to be very durable, having even larger bearings than the GM 454.
My guess would be the 460 aluminum timing cover corroded through because the anti-freeze was not changed out often enough, certainly not every three years as required. The PO probably figured that the low miles excepted this vital service.
What happens when the coolant is not changed is that the coolant often becomes acidic and the 460 is notorious for the timing cover corroding, as it is the rear water-pump wall separating the coolant from the crankcase (timing chain). Water in the oil severely damages bearings, leading to excess wear. Glycol anti-freeze is said to accelerate the damage.
The clues are the damaged heater core, the necessity of radiator replacement and, if they weren't sure where the leak was coming from, swapping out cylinder heads with suspected head gasket leaks. The heads may have been earlier, thicker castings and even older ('69, '70) small chamber high compression heads which were once deemed desirable for power and fuel economy. Radiators do not corrode so easily from the outside as they do internally.
Also regarding swapped heads, there does also seem to be a problem with engines that have been parked for long periods, not properly moth-balled and not run much. Idle motorhomes come to mind. Cylinder walls rust and gum up the rings as they scrape clean, causing rings to stick in their lands and ruin compression. In addition, this scenario often seems to wear out valve guides at lower mileage as though the stems may also have rusted from sitting and slow condensation. The rough stem surface then may gall the guides. In some cases valves will actually stick on engines sitting idle for years, and one might therefore suppose that all neglected valves may suffer some lesser corrosion. I imagine it to be similar to little-used disc brakes that tend to gather surface rust, a more common observation. This is only reasoned conjecture on my part, however. But regarding the possibilty, it does warrant starting, driving and thoroughly warming engines periodically, perhaps weekly, to recoat them with protective oil film.
One of my first engine overhauls was also the Ford T-bird 312 Police Intercepter V8. It was in a 1957 Fairlane 500 that I got for $200 when it was only 7 years old. Unfortunately I was changing out the non-detergent break-in oil on a twin cylinder, pneumatic, axle-lifting, truck hoist when the car met it's demise.
It was graduation weekend and I was looking forward to hot-rodding it after babying it for the first 500 miles. Near quitting time, I was still working at the service station and my buddy was eager to help while I was busy. The long-wheelbase, double floor-cylinder truck hoist could safely be used to lift these old cars by their bumpers, leaving our auto frame-hoist free for customers.
The SNAFU was that my buddy began letting the car down one cylinder at a time instead of carefully lowering both simultaneously. Lowering the rear only, the front bumper stretched right off the forward axle cradle and dumped the car off the hoist on it's side. Needless to say, I was wasn't pleased. But thank God no one was hurt.
Good luck with your adventures and watch out for falling vehicles.
Wes
...
