Re: Overheating SB C2 w/AC when not moving
Duke,
You bring up a interesting thought I just had regarding galvanic corrosion on C1 aluminum radiators.
In 1960 SHP applications, a aluminum Top Tank radiator was used. The tank was simply for overflow, not expansion like the C2 design.
This radiator was directly mounted to the radiator/core support vertical sides using bolts through aluminum side brackets with integral pressed in threaded inserts.
On a C1, the core support not only bolts at the sides to the fiberglass inner skirts, but also attached directly to the frame via 2 carriage bolts. There is a flat rubber shock insulator that the 2 bolts pass through, but no rubber sleeves to insulate the bolts from touching the frame member it's attached to. It's possible for the bolts to scrape and touch the member. This member is the 3rd Arm frame mounted steering bracket.
1961 & 1962 used a aluminum radiator similar to the later C2 applications, however the mounting was different. They were still bolted to the verticals of the core support, but the bottom of the support now had a raised filler section to accommodate 2 rubber isolator disks to electrically insulate the radiator from the grounded core support. But not guaranteed to be insulated from ground as the lower bolt connection method stayed the same.
By design, the 1960 Top Tank radiator was directly connected to ground. I have seen those radiators in horrible condition, but some not as bad.
I'm thinking the badly corroded ones had those lower bolts touching the frame member sides therefore grounding it. Possibly the ones that lasted was because those bolts didn't touch the frame.
It appears to me that the engineers discovered this issue on the top tank radiator configuration in 1960, and therefore changed the design for the later 2 years, and beyond with rubber isolators at the bottom. But the sides were still bolted directly to the core support.
It seems that galvanic corrosion was and is possible on any later C1 with a aluminum radiator.
Rich
PS Yes, C2 aluminum radiator core tubes cannot be inspected in a installed system, but if the system is drained you can remove the upper hose and use a borescope to have a look. If the radiator is removed same method at the inlet at the bottom.
Duke,
You bring up a interesting thought I just had regarding galvanic corrosion on C1 aluminum radiators.
In 1960 SHP applications, a aluminum Top Tank radiator was used. The tank was simply for overflow, not expansion like the C2 design.
This radiator was directly mounted to the radiator/core support vertical sides using bolts through aluminum side brackets with integral pressed in threaded inserts.
On a C1, the core support not only bolts at the sides to the fiberglass inner skirts, but also attached directly to the frame via 2 carriage bolts. There is a flat rubber shock insulator that the 2 bolts pass through, but no rubber sleeves to insulate the bolts from touching the frame member it's attached to. It's possible for the bolts to scrape and touch the member. This member is the 3rd Arm frame mounted steering bracket.
1961 & 1962 used a aluminum radiator similar to the later C2 applications, however the mounting was different. They were still bolted to the verticals of the core support, but the bottom of the support now had a raised filler section to accommodate 2 rubber isolator disks to electrically insulate the radiator from the grounded core support. But not guaranteed to be insulated from ground as the lower bolt connection method stayed the same.
By design, the 1960 Top Tank radiator was directly connected to ground. I have seen those radiators in horrible condition, but some not as bad.
I'm thinking the badly corroded ones had those lower bolts touching the frame member sides therefore grounding it. Possibly the ones that lasted was because those bolts didn't touch the frame.
It appears to me that the engineers discovered this issue on the top tank radiator configuration in 1960, and therefore changed the design for the later 2 years, and beyond with rubber isolators at the bottom. But the sides were still bolted directly to the core support.
It seems that galvanic corrosion was and is possible on any later C1 with a aluminum radiator.
Rich
PS Yes, C2 aluminum radiator core tubes cannot be inspected in a installed system, but if the system is drained you can remove the upper hose and use a borescope to have a look. If the radiator is removed same method at the inlet at the bottom.
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