| aluminum intake manifold install on 455 [message #364952] |
Thu, 24 June 2021 12:20  |
rgogan
Messages: 82
Registered: February 2004
Location: Milwaukee, WI
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Finally installed my aluminum intake manifold after sitting on the shelf for 6-10 years. Purchased from Jim Bounds. Casting labeled "RPM'.
#1 casting is about .25 inches thicker (higher) than the original steel casting.
#2 as a consequence, the passenger side venturi bracket would not fit without grinding it down
#3 also, the AC compressor bracket does not line up with the bored and tapped hole for it in the aluminum manifold because of the increased height. No solution for this yet. The outer part of the AC bracket attached well to the head bolt fixture for it and that seems a solid enough mount for it now.
#4 the vacuum port behind the carburetor was moved forward for unknown reasons and it interferes with the fit of the accelerator mounting bar on the back of the carb. Had to grind that mounting bar down too.
The fit to the heads seemed excellent. My head thickness after machining was 1.986" at the short head bolt area. With the head gasket compressed to 0.037 this kept the fit perfect using Jim Patterson's intake manifold gasket and block off plates with ultrablack RTV. (used entire tube). Still have not fired up the engine to check for leaks. Did have a leak at the thermostat housing. Seems like the recess for the thermostat was not machined deeply enough in the intake manifold. The high flow thermostat prevented the gasket from sealing. Will redo using two gaskets. More progress reports to follow.
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