Offenhauser 5489 Intake Install
Getting around to installing the correct after-market 4 bbl intake on my 1965 Dart 273. Bought this Offy 5489 on ebay several years ago at a good price (~$120) and before shipping rates became outrageous. Good because I've seen them sell here for $250 +$80 shipping and Summit lists new ones for $540 (buy today receive in May). Perhaps they cast new ones once they get enough orders. I attach an installation manual I found. Currently I have an Edelbrock intake for 1966+ installed, which required counter-sinking the holes and using flat-head bolts w/ conical underside, which was all I could find at the time.
Three issues I've had. My question is the large 1/2"NPT tapped hole the rear where a head coolant port is normally blocked. I think the port is there so a head can be used on either L or R side, plus allows removing the sand core. It isn't factory, based on photos I've found of the 5489 manifold here, plus the OE iron manifold. I recall people doing such to run an external cooling tube to modify the coolant flow. Anyone know the whys and benfits? I cleaned it up with an NPT tap and will plug it for now. I don't plan to race and don't want to try out-thinking the engine designers.
Another problem was that the bypass port had a rusty steel nipple. Could have been cleaned in place and used as-is but I prefer stainless or brass w/ teflon tape, so figured I'd remove it like I did the steel heater nipple. As often happens, the steel tube just collapsed under a pipe wrench without turning, even after heating the aluminum a long time with a propane torch. I had to cut it flush, cut an axial slot with hand jigsaw, then peel the shell inward with a punch. That cut the threads a bit, but ran an NPT tap in to cut them bit deeper and eliminate the slot.
Another problem is that one T-stat bolt hole is stripped. Need to buy a 3/8-16 thread insert and tap to fix it. That bolt needs to be secure to support an AC bracket for Sanden compressor. Rolling my own AC brackets and will post if success.
Getting around to installing the correct after-market 4 bbl intake on my 1965 Dart 273. Bought this Offy 5489 on ebay several years ago at a good price (~$120) and before shipping rates became outrageous. Good because I've seen them sell here for $250 +$80 shipping and Summit lists new ones for $540 (buy today receive in May). Perhaps they cast new ones once they get enough orders. I attach an installation manual I found. Currently I have an Edelbrock intake for 1966+ installed, which required counter-sinking the holes and using flat-head bolts w/ conical underside, which was all I could find at the time.
Three issues I've had. My question is the large 1/2"NPT tapped hole the rear where a head coolant port is normally blocked. I think the port is there so a head can be used on either L or R side, plus allows removing the sand core. It isn't factory, based on photos I've found of the 5489 manifold here, plus the OE iron manifold. I recall people doing such to run an external cooling tube to modify the coolant flow. Anyone know the whys and benfits? I cleaned it up with an NPT tap and will plug it for now. I don't plan to race and don't want to try out-thinking the engine designers.
Another problem was that the bypass port had a rusty steel nipple. Could have been cleaned in place and used as-is but I prefer stainless or brass w/ teflon tape, so figured I'd remove it like I did the steel heater nipple. As often happens, the steel tube just collapsed under a pipe wrench without turning, even after heating the aluminum a long time with a propane torch. I had to cut it flush, cut an axial slot with hand jigsaw, then peel the shell inward with a punch. That cut the threads a bit, but ran an NPT tap in to cut them bit deeper and eliminate the slot.
Another problem is that one T-stat bolt hole is stripped. Need to buy a 3/8-16 thread insert and tap to fix it. That bolt needs to be secure to support an AC bracket for Sanden compressor. Rolling my own AC brackets and will post if success.
