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Hey just wanted to introduce myself. I'm new to rotary, though I'm a mechanic by day. So a couple things does anyone have a koyo radiator in there FC? Cause the one I just bought has one and it seems to slightly hit the hood, at the rad. cap. The 6th port is disconnected and not tied up to always be open, or maybe it is always open. Could someone elaborate on how to open the 6th port as opposed to just having it disconnected, that would be great. It has a racing beat header and trust exhaust. Is any manual better than the other for the FC's? https://www.nopistons.com/forums/pub...IR#>/boink.gif I'm stocked to finally have found a nice FC for a nice price($2300). Any info would be great. Now I will see if and how the search works, not sure if there is one yet. Thanks, Chris https://www.nopistons.com/forums/pub...R#>/tongue.gif

Well the 6th port opens by exhaust backpressure, on the 86-88fc, while the 89-92 are opened by the air pump.

Welcome to nopistons! Feel free to post in the 2nd gen section with specific questions, you'll get more answers there.