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1977 F100 - 460 from a 1969 Lincoln, C6 Trans, 9" Rear
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Discussion Starter · #61 ·
HI
spark knock is timing.. re-set timing to a little lower 10 or 12 degs. with vacuum off and plugged, NOT 15* ... If it does not run at 10 or 12* you have problems with timing or distributor. or the damnpner is OFF..(slipped)

good luck take care be safe
tim
Tim, that’s what I was thinking as well. I turned it down to 15 initially and it ran okay, not great. A week later it would not start at all, it would just backfire through the carb. I’m thinking you and Dacofa are right - the balancer has slipped. It makes a lot of sense.
Dacofa - I like the sleeve you have there, nice and clean. I’ll start looking for that. I’ve considered the electric fuel pump setup but for now will stick with Mechanical, unless I can’t get the heat under control.
 

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Vapor lock is typically a symptom of a larger problem. That truck ran fine for a loooooong time with out any heat wrap. Don't get me wrong, you should absolutely protect it from heat, but you have to find the actual problem. Pull the balancer a get a look at it. Best to compare it to a new one, note the position of the woodruff key compared to the TDC mark. Also, pull the distributor cap, and bar the engine back and forth, this will tell you if you have slop in the timing chain or distributor gear. Also, is this truck running lean? A persistent lean condition will raise underwood temps quite a bit. Are all of your shrouds in place? Is the fan working correctly? Quit playing around with the manner in which the fuel is being delivered.
 

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HI,
Pull #1 plug. drop a straw into it and rotate the motor by hand. It does not matter if it is on the exhaust or the compression stroke as on both the piston should be at the top and the mark on the dampener should be at 0*... Make sure your not bending the straw and watch it carefully.. it only takes a couple of deg. to move the piston off TDC alot .. also see how much the crank moves (deg.) before the piston moves.. UP/down.
REMEMBER THE CRANK TURNS TWICE TO ONE TURN OF THE DISTRIBUTOR
it almost acts like your 180* out (on the wrong stroke of the piston)
good luck take care be safe
tim
 

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1977 F100 - 460 from a 1969 Lincoln, C6 Trans, 9" Rear
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Discussion Starter · #64 ·
Hey guys, didn’t see your comments til now, but ironically went out and checked the TDC on #1 and compared to what the balanced said. It’s spot on - TDC on the balancer matches perfectly with the peak of the piston.
Arnold - I pulled the plugs last week to do compression check. Plugs 1-2-5-6 all had a nice tan look, plugs 3-4-7 had a dark look and 8 was very dark and oily. I richened the carb mixture last week for shits and giggles and no improvement in terms of spark knock or carb pop.
Since I had more lunch break time after checking TDC, I fired the truck up to play with timing. I brought it down to 18*(originally set at 23*) plugged the vac advance, and throttled up while in park, and boy it backfired in the carb/air filter housing quite a bit. I then rotated it in advance as far as I could (t-stat outlet hits the vac advance), which was 30* per my timing light. Still popped but no heavy backfire like when it was at 18*.
Thinking about replacing plugs, trying an octane booster, or looking for something else if you guys have ideas. Greatly appreciate your input - previous owner had next to no info on it and he bought it from a consignor.
 

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HI
Plugs or carb mixture is NOT going to do anything to the problem your having... it is NOT going to effect timing. your problem is timing YOU HAVE TO BE ABLE FOR IT TO RUN PROPERLY AT 10 TO 12 DEG's.. you are ether using the wrong plug for #1 (first plug on passanger side) or the timing chain is shot or are you using the proper firing order and rotation.. When you set it does it bounce around or is it solid at what you set it at??
Don't worry about where the diragam shows #1 as long as the rotor is pointing at #1 when at TDC of the compression stroke the motor don't care.. as long as the rest is right...

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good luck take care be safe
tim
 

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1977 F100 - 460 from a 1969 Lincoln, C6 Trans, 9" Rear
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Discussion Starter · #66 ·
Hey Tim, the timing marks stayed spot on so long as I didn’t touch the distributor. Was using the plug wire on the #1 cylinder, first one on the passenger side.
im with you on the timing part, I can’t understand why it needs to be so high to run decently. Turning it down to 15* it’ll idle okay but immediately start backfiring through the carb as soon as I apply throttle. Just at a loss at this point. I’ll pull the distributor cap off tomorrow and rotate the crank back and forth to see if there’s any chain slop, but I used my scope cam and the piston seemed to be very responsive to me turning the crank.
I might throw my in-line spark checker on each wire just to see if there’s a cylinder that misfires, at least I could potentially eliminate a spark/ignition issue.
 

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Discussion Starter · #68 ·
At one point, about 17-18, right between red/green. Now it’s down around 14 if I remember correctly. Not exactly sure why - didn’t adjust anything. I’ll put the gauge back on this weekend hopefully to see what it’s reading now.
 

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Discussion Starter · #70 ·
It has a 1 in/Hg variance that rapidly moves. Picture shows it right at the red/green split. It would rapidly move between 16-17 at idle but nothing more. Font Circle Gauge Auto part Technology
 

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HI
Yes the piston is solidly attached to the crank and in time with the crank that can't change.. chain slop won't show up at the piston . the chain has nothing to do with the piston and crank it has to do with the crank to cam and distributor. the timing chain drives the cam, the distributor and the oil pump off the crank sprocket.. and you are using the firing order shown in my diagram along with how the piston's are numbered..

good luck take care be safe
tim
 

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Discussion Starter · #72 ·
Hey Tim, I don’t know why I didn’t think about that piston/crank correlation. I plan to pull the cap today and check the distributor for any slop in movement. I’ll double check that the firing order is correct as well while I’m out there.
 

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A rapid flutter in vaccum typically indicates valve train issues. Have you had the valve cover off? Setting timing and carburetor adjustments on an engine with valve train problems can be problematic to say the least. Is this a stock cam?
 

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Discussion Starter · #74 ·
Hey Arnold, I’m tempted to peel the covers off to check the valvetrain. Since the truck is new to me and the PO gave no info about it, I’m guessing it’s a stock cam, but don’t know for sure. I had read that a flutter was a valvetrain issue but assumed it needed to be a larger fluctuation (3-4 in/Hg).
 

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Discussion Starter · #75 ·
Got a little bored at work so I went out to pop the distributor cap off. The rotor seems to turn relative to the crank movement correctly. It turns CCW. The firing order/wires are ran correctly per your diagram, Tim. Put the crank at #1 TDC (I should note that I did not have the spark plug pulled to actually verify that it was at #1 TDC - guess I might be going back out there to check again) and the rotor was just slightly past the #1 point on the cap, which makes sense to me since the timing is so far advanced - 23*

The picture below shows how it looks - the little black mark to the left of the QR code is the #1 point. Automotive tire Blue Automotive fuel system Motor vehicle Hood
 

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Stock cam, I'm checking the valve train out with an inch of flutter. Especially if vacuum is low. How's the exhaust? Vacuum issues are correlated directly to the pumping action of the engine. I find vacuum leaks with propane or carb and choke cleaner. Restricted muffler and cats are typically found by tapping with a deadblow. Pinching off vacuum lines as close to the manifold one at a time can be helpful as well. Hook up a timing light to monitor rpm in real time while testing. Being that this is a new to you truck, you need to get vitals before you keep changing things. You've been messing with so many things now, you're going to end up being your own worst enemy and creating more problems than you started with. Back to basics. Start over. Get your timing issues and potential valve train problems (and any other vacuum related problem) sorted out before you change anything else.
 

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Discussion Starter · #77 ·
Thanks Arnold! One of the PO’s put this 460 in from a 69 Lincoln, does have headers (unsure of brand). Exhaust seems normal all things considered, but I’ll have to check into it further to identify anything else.
I’ve checked for Vac leaks using the starting fluid method, but I’ll recheck the vac lines again. Might just plug the ports on the carb just to see if it works. There’s a Vac line to the PCV, one for the distributor, and one for the transmission. Then there’s a horseshoe loop hose on the intake that looks odd, but it’s there and not leaking.
My timing light is digital and is showing about 900-1000 RPM at idle in park. I tried turning the idle down and that’s as far as it’ll go.
Going to peel off valve covers in the next week or so just to check everything out on that end.
 

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HI anytime the crank is at TDC the #1 piston IS at the top.. We already know this.. its a matter if its on the compression stroke or the exhaust stroke (Because the crank turns twice to one turn of the distributor).. The 4 stroke motor works like this
1) intake (piston going down)
2) compression (piston coming up, at the top of this stroke the crank is at TDC and the one you want to match up with the #1 wire in the cap)
3) power (Piston going down after firing)
4) Exhaust (piston going back up to expel exhaust, AT THE TOP OF THIS STROKE THE CRANK WELL ALSO BE AT TDC BUT NOT THE ONE YOU WANT TO MATCH UP WITH YOUR #1 WIRE.
that is where a lot of people get confused.
You need to be sure you are on the compression stroke to match up the #1 wire.. Screw a piece of paper towel simi tightly into the #1 plug hole slowly turn the motor by hand until it pops out make sure you did not roll past TDC the line it up to TDC and That is where the #1 plug wire should line up..

good luck take care be safe
tim
 

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HI if the idle won't go below 900 or 1000 no matter if the idle screw is back all the way off you have a major vacuum leak.. and no wonder you can't set the timing, timing is set at idle speed of 650 to 750 rpm's
tim
 

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Discussion Starter · #80 ·
Tim and Arnold, you guys have been very helpful! I’ll check out any Vac leaks again and just be as thorough as I can. I felt like the idle was slightly high but when in gear, it drops and doesn’t want to act like it’s going to die.
Gameplan will be to identify and fix any vacuum leaks, then if the issue persists, check under the valve covers, and go from there.
 
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