Still shaking at idle

[LEROY POLL]

HELLO FALC64

....HERE GOES..... WITH A SMALLER CHARGE TO EXPLODE,..... YOU WILL NEED LESS LEAD TIME..( OR ADVANCE)...TO FIRE THE POWER CYCLE. THIS IS ONE OF THE THING THAT SEEMS TO BE A PROBLEM ON THIS SUBJECT.

.... THE THINKING THAT MORE ADVANCE WILL YEILD MORE POWER IS NOT TRUE. THE TRUTH HERE IS THAT THE CORRECT TIMING WILL YEILD MORE POWER,.... MORE THAN INCORRECT TIMING. OVER ADVANCING THE THE TIMING WILL GIVE LESS POWER,....UNDER ADVANCING THE TIMING WILL GIVE LESS POWER. THE TIME NEEDED TO FIRE THE CHARGE IS DIRECTLY RELATED TO THE SIZE OF THE CHARGE.

.....250 CU IN. HAS 41.66 + C/CHAMBER=APPROX. 45.00 CU IN

.....200 CU IN. HAS 33.33 + C/CHAMBER=APPROX. 36.50 CU IN.

.....170 CU IN. HAS 28.33 + C/CHAMBER=APPROX. 31.50 CU IN.

.... YOUR MOTOR AT 7000 FT. WILL HAVE AS SMALLER CHARGE(LESS AIR PRESSURE) AND SHOULDN'T NEED THE SAME AS A MOTOR AT SEA LEVEL.

.... WHEN IT RUNS GOOD AT THE LOWER END, BUT PINGS AT HIGHER SPEEDS IS WHERE SOME HAVE GONE TRYING TO GET MORE POWER.

.... I BELIEVE 20* AT IDLE WOULD BE TOO MUCH. I THINK STEVE HAS IT RIGHT WHEN HE SAID SOME HAVE FOUND THAT THE 200 SIX W/C4 CAN GIVE PROBLEMS. HIS ANSWER IS A GOOD ONE. HE SAID 16* TO START OUT AND THEN NO VACUUM AT ALL, AND THE HAVE THE DIST. SET FOR 10* INSIDE WITH THE WEIGHTS. THIS WILL GIVE YOU 36* OVERALL ADVANCE. THIS IS THE CORRECT TIMING FOR OUR MOTOR. HOWEVER YOU COULD USE 34* TO 35*.

.... I HAVE FOUND THAT ANYONE WHO HAS A PROBLEM FOR A LONG TIME.... AND HAS DONE AS MUCH AS YOU HAVE.....USUALLY HAS MORE THAN ONE PROBLEM. I DO BELIEVE YOU WILL FIND THAT YOU HAVE TWO OR MORE PROBLEMS. I THINK THE CARB. AND TIMING ARE TWO OF THEM. MAYBE THE ONLY TWO!!

.... START BY JUST PLUGGING THE VACUUM ADV. AND TRY THAT FIRST BY TEST DRIVING IT AROUND THE BLOCK. THEN MOVE TO 16* & TEST..DRIVE. THEN TO 12* & TEST...DRIVE. THEN TO 8* & TEST.... DRIVE. BY MOVING CLOSER TO TOP/DEAD/CENTER IT WILL GIVE A SMOOTHER IDLE. IF YOU STILL HAVE A PROBLEM THEN LEAVE THE TIMING SET AT 8* AND GO FOR THE CARB. ADJUSTMENT TO HELP. IF THAT DOESN'T HELP THEN PUT A KNOWN GOOD CARB. BACK ON. IF IT RUNS BETTER OR WORSE.... IT'S THE CARB. .IF NO CHANGE YOU ARE LOOKING AT SOMETHING WITH THE FIRING OF THE MIXTURE. WEAK SPARK, BAD SPARKPLUG, WIRES CROSSED, CRACKED WIRES, UNEVEN FIRING DO TO DIFFERENT SPARKPLUG SIZE( HOT TO COLD ), CHECK COIL WIRE FOR BURNNING OUT DO TO HOTTER COIL AND BAD AND BROKEN CONTACTS. THE COIL WIRE FIRES EVERY TIME AND SOMETIMES CAN'T TAKE THE EXTRA LOAD.

.... ONE QUESTION. HOW FAST DOES YOUR MOTOR START UP? 1/4 TURN.... 1/2 TURN....1 FULL TURN.... 2 TURNS.?

.... THAT'S A LOT TO DO, BUT WILL GIVE YOU SOME MORE INFO TO WORK WITH WHEN YOU ARE THROUGH.

LOTS OF LUCK....LOL

LIVE IN GRACE

LEROY POLL

 

[Anonymous]

If you've got a PCV, maybe your breather filter has the wrong amount of air restriction. Your head might also have casting flash causing excessive turbulence. Since you said that the car ran rather smoothly warming up, maybe you should try a cooler thermostat. Just a thought.

Good Luck!

 

[Anonymous]

I though I'd update this thread just to keep it alive.

The latest...

I've worked with the timing a bit. Now I have it set at 12° at idle. the vac advance is connect to a port on the YF that has zero vac at idle and kicks in just off idle and tops out at "full" vac around 2K rpm (no load). No matter what I've done in recent history with timing I never get any ping.

This did not change the vibration at all!!!!

I think the changes in vibration I've felt at various warm vs cold conditions are simply a matter of different idle rpms at different warm/cold conditions.

 

[Anonymous]

Since you made this thread active again I decided to add my two cents after tearing apart my engine a couple of weeks ago....

If you remember I also had this vibration and I was running the same C8 block and C4 tranny....

I found a couple of things that could have caused the vibration for me, I had a couple of loose bolts on the bellhousing.

But as I was reading the posts tonight I had an interesting thought. Has anyone done any research on the C4... since this seems to be limited to C4 drivers only, maybe there is an issue with the C4 in combination with the 200 block... balance is everything on these sixes and is there anything in the TC, C4 that could be causing this problem...

I am wondering if by adjusting the carb and timing you are only compensating for some other internal conflict with the crank and C4... thus by getting the RPM's and fuel circuits correct to mask the problem, but not really fix it....

I ask because I tried all of the same above ideas and always would get a better idle then after time, it would revert back to the rough. Maybe the issue here is not the engine, but the drivetrain...

Unfortunately I will not be able to help you solve this since I have decided to drop the C4 in favor of a manual T5, if you cannot fix it, replace it.
I always wanted the stick anyway...

just a thought....

 

[Anonymous]

I've wondered the same thing Jimbo. I've had my first 200/C4 combo in the car since 1986 when I said goodbye to the Ford-o-matic 2-speed. I think I put 20-30K miles on that combination before the vibration became an issue. In that same time period I moved from sea level to 7000 ft and stopped using leaded gas.... then last year I put a complete 200 and C4 from a 65 that was factory built that way. It still shakes I think I'll eventually go to a stick too or my ultimate wish to drop the wagon body on a 4wd Bronco or truck frame. But until I get more kids through or at least into college (and keep their cars running) I just want it run decently.