bizjetmech
Active Member
Asked about this last year, got the electrical issues fixed, got busy, project went on the back burner.
Car: Dart Sport, 1973...original 340 had cracked block
Located replacement 340, forged crank, stock rods, Ross pistons, calculated CR 9.6/1 or thereabouts...heads from the original 1973 motor, with 2.02 intake valves. Cam: Lunati 00043 (picked up several years ago (new))...230/230 duration @ .050, .480/.480 lift., 107 degree centerline. Cam card says installing at 107 degree centerline will "make this cam 2 degrees advanced".
Note: Installed this cam with the "dots matched" (double roller timing chain), as the sprockets had only single keyways, and nobody seems to stock offset keys around here.
Installed last year, had electrical issues (no 12v to coil). Finally figured out that pigtail/harness to ECU was bad, even though it "rang out" okay. Car consistently starts now. Was concerned about the new cam (due to all of the cranking, with no start) but pulled the intake, cam looks fine.
Car starts, sorta runs. Dies when you drop it into gear, unless you are lucky. Runs like crap if you can manage to get it rolling (part throttle highway cruise sorta okay, raises all kinds of hell when you try to floor it, backfires, etc.......)
Won't idle below 1100 rpm. Won't idle with LESS THAN 25 DEGREES OF ADVANCE.....dies immediately once the distributor is turned below that mark. Acts like it has a giant vacuum leak (Intake...new Edelbrock "Air Gap"). Checked, couldn't find any (had previously found that the vaccuum advance diaphragm in the distributor was leaking, fixed/replaced). Tried two different carbs, Edelbrock/AFB and a new Holley Street Avenger 650......the new Holley actually seemed to run worse. Running the idle screws in/closed causes the idle to fall off like you would expect, but once they are out a turn or two, seems like you can back them out the rest of the way without affecting the idle.
All cylinders/header pipes are within 5 degrees of each other, when checked with infrared thermometer. Engine runs hotter than the old junkyard 360 it previously had in it, but doesn't come close to overheating..
At this point, plan on locating my degree wheel and checking this cam, ordering another timing chain with 3 keyways. Half tempted to just say "F-it" and toss this cam in the trash, and put a nice stock 340 cam in it.
Any ideas, other than:
-Taking it someplace here in the KC area, where they haven't become totally pizzed off/frustrated, and have the time/expertise/equipment to figure out what I did wrong, or
-Yank this motor, put it on E-Bay, and put the junkyard 360 back in it.
Trying to get something figured out before I have to go out of town for two months.
Car: Dart Sport, 1973...original 340 had cracked block
Located replacement 340, forged crank, stock rods, Ross pistons, calculated CR 9.6/1 or thereabouts...heads from the original 1973 motor, with 2.02 intake valves. Cam: Lunati 00043 (picked up several years ago (new))...230/230 duration @ .050, .480/.480 lift., 107 degree centerline. Cam card says installing at 107 degree centerline will "make this cam 2 degrees advanced".
Note: Installed this cam with the "dots matched" (double roller timing chain), as the sprockets had only single keyways, and nobody seems to stock offset keys around here.
Installed last year, had electrical issues (no 12v to coil). Finally figured out that pigtail/harness to ECU was bad, even though it "rang out" okay. Car consistently starts now. Was concerned about the new cam (due to all of the cranking, with no start) but pulled the intake, cam looks fine.
Car starts, sorta runs. Dies when you drop it into gear, unless you are lucky. Runs like crap if you can manage to get it rolling (part throttle highway cruise sorta okay, raises all kinds of hell when you try to floor it, backfires, etc.......)
Won't idle below 1100 rpm. Won't idle with LESS THAN 25 DEGREES OF ADVANCE.....dies immediately once the distributor is turned below that mark. Acts like it has a giant vacuum leak (Intake...new Edelbrock "Air Gap"). Checked, couldn't find any (had previously found that the vaccuum advance diaphragm in the distributor was leaking, fixed/replaced). Tried two different carbs, Edelbrock/AFB and a new Holley Street Avenger 650......the new Holley actually seemed to run worse. Running the idle screws in/closed causes the idle to fall off like you would expect, but once they are out a turn or two, seems like you can back them out the rest of the way without affecting the idle.
All cylinders/header pipes are within 5 degrees of each other, when checked with infrared thermometer. Engine runs hotter than the old junkyard 360 it previously had in it, but doesn't come close to overheating..
At this point, plan on locating my degree wheel and checking this cam, ordering another timing chain with 3 keyways. Half tempted to just say "F-it" and toss this cam in the trash, and put a nice stock 340 cam in it.
Any ideas, other than:
-Taking it someplace here in the KC area, where they haven't become totally pizzed off/frustrated, and have the time/expertise/equipment to figure out what I did wrong, or
-Yank this motor, put it on E-Bay, and put the junkyard 360 back in it.
Trying to get something figured out before I have to go out of town for two months.
