block differences
Team Owner
Joined: Oct 2000
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From: Washington Michigan
Remember that Service parts had to fit perfectly without regard to the block source - castings and machining had to be the same or there would have been chaos in the field. Same thing applied to McKinnon (Canada) "K"-prefix blocks - they all had to be fully interchangeable with each other.
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Joined: Mar 2001
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From: Mustang OK
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As John mentioned, the Flint blocks had a square head pipe plug in an oil passage above the timing cover. This passage was drilled into the middle galley in the lifter valley. The BOSS for that oil passage is in all of the Tonawanda blocks, but not drilled and tapped.
When I build an engine that came from Tonawanda, I frequently drill and tap the passage and install an oil pressure gauge so that I can read pressure right at the engine. THIS NEEDS TO BE DONE BEFORE THE BLOCK GOES TO THE MACHINE SHOP SO THAT ALL THE METAL PARTICLES WILL BE REMOVED FROM THE OIL PASSAGE!!!!
This picture shows the boss going down to the oil galley.
When I build an engine that came from Tonawanda, I frequently drill and tap the passage and install an oil pressure gauge so that I can read pressure right at the engine. THIS NEEDS TO BE DONE BEFORE THE BLOCK GOES TO THE MACHINE SHOP SO THAT ALL THE METAL PARTICLES WILL BE REMOVED FROM THE OIL PASSAGE!!!!
This picture shows the boss going down to the oil galley.
Racer
Joined: Jul 2005
Posts: 353
Likes: 16
From: Marlboro New York
The basic castings are the same, and Flint and Tonawanda also built the same casting numbers in many cases. The Tonawanda machining process was slightly different than Flint, so the Flint block was the only one that had a 1/8" NPT square-head plug just above the timing cover - it wasn't required on a Tonawanda block.
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Joined: Mar 2001
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From: Mustang OK
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ORIGINALLY, it was on ALLLLLLLLLLLLL 55 265 blocks for oil supply to the oil filter. An Oil filter WAS NOT standard on a 55 block (the 55 block did not even have the pad for a filter). Anyone have a picture of a 55 ONLY oil filter?
In 55, the filter was still an option, and the mounting bracket for the filter was positioned BETWEEN the thermostat opening on the intake manifold and the thermostat housing. Oil supply TO the filter came from that front hole and oil was RETURNED to the crankcase through a threaded fitting/hose on the right side of the intake manifold next to the exhaust crossover passage. As far as I know, ALLLLLLLLLL 55 intake manifolds had the threaded hole and a pipe plug was installed if the engine did not get a filter. The threaded hole was there whether or not the engine got a filter because sometimes the dealer installed a filter before delivery to the customer.
And, as mentioned, that hole at the front of the block was also used to supply oil for such purposes as the air compressor on big trucks with air brakes.
In 55, the filter was still an option, and the mounting bracket for the filter was positioned BETWEEN the thermostat opening on the intake manifold and the thermostat housing. Oil supply TO the filter came from that front hole and oil was RETURNED to the crankcase through a threaded fitting/hose on the right side of the intake manifold next to the exhaust crossover passage. As far as I know, ALLLLLLLLLL 55 intake manifolds had the threaded hole and a pipe plug was installed if the engine did not get a filter. The threaded hole was there whether or not the engine got a filter because sometimes the dealer installed a filter before delivery to the customer.
And, as mentioned, that hole at the front of the block was also used to supply oil for such purposes as the air compressor on big trucks with air brakes.
Team Owner
Joined: Apr 2008
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From: Middle TN by way of KY, OH, VA, IL, CA, FL, NY, SC, HI
ORIGINALLY, it was on ALLLLLLLLLLLLL 55 265 blocks for oil supply to the oil filter. An Oil filter WAS NOT standard on a 55 block (the 55 block did not even have the pad for a filter). Anyone have a picture of a 55 ONLY oil filter?
In 55, the filter was still an option, and the mounting bracket for the filter was positioned BETWEEN the thermostat opening on the intake manifold and the thermostat housing. Oil supply TO the filter came from that front hole and oil was RETURNED to the crankcase through a threaded fitting/hose on the right side of the intake manifold next to the exhaust crossover passage. As far as I know, ALLLLLLLLLL 55 intake manifolds had the threaded hole and a pipe plug was installed if the engine did not get a filter. The threaded hole was there whether or not the engine got a filter because sometimes the dealer installed a filter before delivery to the customer.
And, as mentioned, that hole at the front of the block was also used to supply oil for such purposes as the air compressor on big trucks with air brakes.
In 55, the filter was still an option, and the mounting bracket for the filter was positioned BETWEEN the thermostat opening on the intake manifold and the thermostat housing. Oil supply TO the filter came from that front hole and oil was RETURNED to the crankcase through a threaded fitting/hose on the right side of the intake manifold next to the exhaust crossover passage. As far as I know, ALLLLLLLLLL 55 intake manifolds had the threaded hole and a pipe plug was installed if the engine did not get a filter. The threaded hole was there whether or not the engine got a filter because sometimes the dealer installed a filter before delivery to the customer.
And, as mentioned, that hole at the front of the block was also used to supply oil for such purposes as the air compressor on big trucks with air brakes.
I do remember those oil filter-less blocks.
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