409 Questions
- Thread starter 409acoupe
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409acoupe
Active Member
It’s true!
My 700R4 has a 12 volt vacuum switch that I hooked directly to manifold vacuum. When manifold vacuum is below 3" the lockup will not engage. Preventing chuggling.
It is supposed to be hooked up to a PORTED side of the carb,not to full manifold vacuum.The "chugging" that most people complained about happened at very light throttle/35-40 mph.The delay valve helps keep the vac.signal steady under those conditions.
I've not had an issue with mine hooked to manifold vacuum but that sounds reasonable. I also have an override switch on my shifter handle and can lock the converter at will. I love this feature for cruising around town. Pulls the rpm' down a bunch.
Locking 2nd and 3rd at will and fourth is still automatic as per stock build but I can lock up 4th to at will. First will not lock up in any instant as there is no hydraulic port. My switch is wired directly to the solenoid, any time you power the solenoid to the overdrive port the clutch will apply except first gear as stated.
Michelangelo
Active Member
Real good info there. Thanks, man.
409acoupe
Active Member
Spent some time tuning on the motor with the new bases in last night. Motor is much happier, primary carb actually reacts to the mixture screws. We bumped the timing up a little. only thing that is still being a little finicky is the vac advance. We have the idle screw in enough that i think we are a little past the transfer slots/holes so the vac advance wants to hang up just a touch. We played with both timed vac port and full vac and seems to be pretty much the same. It's a new pertronix distributor with ignitor II but have confirmed with Pertronix the can is not adjustable on this unit. So gonna drive it a little more and see how the motor responds to the tune. Have the idle set around 7-800 so it pulls down closer to 500 in gear. A little lower than i would ultimately like but trying to get the advance happy.
409acoupe
Active Member
2200 stall so nothing crazy
409acoupe
Active Member
Car weighs 2800lbs
That should have been 1,000 lbs,not 100.Sorry.
409acoupe
Active Member
Sometimes i wonder about my luck with new parts! My stealth alternator (looks like a generator) burnt up after 150 miles. Only thing i'm running for major power users is a Maradyne electric fan and a Holley fuel pump. According to specs on both the fan draws 19 amps peak and the fuel pump 2 so i figure with everything else tops the car is maybe pulling 30-35 if that. alternator is rated for 45 at idle 60 at rmp so i figured it was lots. it wasn't cheap either at $250US Not getting much support from the vendor so i bit the bullet and ordered a powermaster powergen for $27 million dollars 
90 amps at rmp. I used a Coachworks coupe 23 harness that uses a high end panel with all of the relays built in including the fan and pump circuits. Was meticulous with the wiring too so at this point i believe it's the alternator not something else. Really thought about going the $70 GM alternator alternator route like i have in the Camaro but just doesn't look right on the coupe so i'm stuck selling a kidney to keep the look proper! ha ha The joys of hot rods
90 amps at rmp. I used a Coachworks coupe 23 harness that uses a high end panel with all of the relays built in including the fan and pump circuits. Was meticulous with the wiring too so at this point i believe it's the alternator not something else. Really thought about going the $70 GM alternator alternator route like i have in the Camaro but just doesn't look right on the coupe so i'm stuck selling a kidney to keep the look proper! ha ha The joys of hot rods
Take that thing apart and see what wrong.
Someone had to build it, so someone should be able to fix it.
Someone had to build it, so someone should be able to fix it.
409acoupe
Active Member
We did pull it apart. We have a great alternator shop in town and he pulled it apart and rattled off a list of the shit that failed in it. Diodes, internal regulator even the windings around the commutator!! Emailed the vendor with all the details of what we found and a breakdown of the entire system in the car so they knew what I’m dealing with a week ago and so far no reply.
If the windings are bad , that could be a tough fix.
409acoupe
Active Member
Put a new powermaster power gen on the car. so far so good. doing some short cruises 30-40 miles round trip till i'm satisfied she's happy. Now on another subject, let's hear some opinions on these plugs. First pic is 2 through 8 and second pic is 1 through 7. I understand the black dry soot look but am not sure what the root cause is yet and i'm most curious about #5, #2 and #8 looking basically great. I have not bumped up the jets yet so still running 55's on the secondaries and 57's on the primary. PSI is set at 3.5 floats are all set right all new needles & seats in each carb. Plugs are NGK gr5's so a little on the hotter side which you think would help with the self cleaning aspect. Should i try a 4? Timing is at 18 initial. The one thing that comes to mind which may sound weird is the carb scoops. when i first drove the car i had the mesh filters in them and the motor ran pig rich and really poor. Pulled the filters off and it was like a new motor! We played with placing just the filters over the primary carb with the scoops removed and you could almost choke the motor out just by placing on the carb by hand. My friend who's a licensed mechanic and almost 40 year hot rodder was blown away by how much those filters effected the carbs. So it has me thinking are the carb scoops still acting as somewhat of a resistance to a real full gulp of air? Thinking of the surface area of a full sized round filter vs the opening of just the scoops.
The motor still has a "poppy" slight miss to it if that makes sense. worse at slow cruise than at higher highway speed but looking at these plugs makes me thing it's related. Seems to be a little harder on fuel than it should be too.
The motor still has a "poppy" slight miss to it if that makes sense. worse at slow cruise than at higher highway speed but looking at these plugs makes me thing it's related. Seems to be a little harder on fuel than it should be too.