Camshaft Timing

[Beardlife]

I could use some help, 1971 360 in an F-250.
I've replaced a couple of distributors, the one on this truck originally had a bad vacuum advance, replaced that, ran it a 12 BTDC, idled great. Buuut, the mechanical advance stuck, so I got a pertronix distributor, an Ignitor I and a matching flamethrower. While I did that, i messed up and accidentally cranked the motor with a chain wrench on the pulley. Put the pertronix in, started it up, ran like crap. It will idle indefinitely, and rev, and with timing set to 10-14 degrees, a timing light is steady. However, it doesnt have enough power to even make it out of the driveway, It just backfires and sort of stalls out, has 15 inches vacuum, which will not improve with tuning of the idle jets, which I know had some effect recently, as I rebuilt the carb before the distributor was replaced for the first time.

I verified TDC with a piston stop, marked it with timing tape, checked ignition timing and firing order. Checked compression, it's 120-125 psi, on all cylinders, and no pushrods are thrown. All valves I can see while cranking are moving (thats numbers 1, 5-6-7-8). Peered down the carb barrel (Holley 1850) to see that the power valve still squirted (it does, from two jets). Pulled the passenger valve cover off to discover that the #1 intake valve was opening 22 degrees after TDC. From what I've found, that should open about 13 BTDC, so I figured I had damaged timing chain, causing a jump when I left the chain wrench on.

Pulled the timing cover, lots of slop in the chain, marks did not line up, and the cam dowel pin was not retained. The washer on the fuel pump eccentric was too small, it had slipped forward. Put on a fresh one (Sealed Power KT3-494-SA1). Found a suitable washer, lined up the marks, and spun it a couple times all the way around to verify the dot on the cam sprocket was straight down when the keyway on the crank sprocket was straight up. Reassembled..... 16 inches of vacuum. Intake valve still opens very late, about 32 degrees from where I expect it to be. I have a spare timing set of the same brand, so i went and counted the teeth. 36, so i figured somehow I got off a couple teeth (each tooth being 18 degrees), and tore it down again. Marks were perfect.

Then I used my little bit of dangerous knowledge to try and move the cam to where in the intake valve opens 13 BTDC. advanced two teeth, or 32 degrees. marks are nowhere near lining up, but the intake valve opens where I think It should, so I figured I'd give it a chance. reassambled, and.... nothing. makes little put-put-put noises, but will not really even cough.

I realize I moved the cam sprocket to the wrong place, but where's the right place, if the intake valve opens some other time? If I just reset the timing chain to where the marks line up, i'll have an intake valve opening late again, and just be back where I started. If I've missed something obvious, what is it?

[tnlprt]

Power valve does not squirt

The accelerator pump does

Those 2 streams are coming out of the squirter nozzles


Why would you line up off the keyway on the crank

Why not use the dot on the crank gear

Pull number 1 plug after the chain is installed correctly

Crank the engine with a finger over the spark plug hole

When it blows it off that is TDC

Drop the dist in with the rotor pointing at number 1 on the cap

Set initial timing at 10-12 degrees BTDC

[Beardlife]

Ok, I re-verified TDC, using the thumb, a spark plug boot jammed in the spark plug hole, and s long screwdriver, all of which agree with the timing tape I added, so i don't think finding TDC is my issue. The dot on the crankshaft tooth is directly above the keyway, so, crank keyway, crank dot, and cam dot all line up again. intake valve still opens way late... is this a problem or not? Am I incorrect in believing the intake valve should open at 13 BTDC? obviously it was running better at 21 after tdc than 13 BTDC, but where is the correct position? I've also noticed there seems to be zero valve overlap on #1, but i don't see how a cam could go flat in a moment.

[71Fe2O3]

Are you at TDC on the compression stroke?
Listen for the air blowing out, as tnlprt recommended.
Also, check vacuum lines and PCV plumbing to rule out vacuum leaks.
Moving the cam sounds pretty dangerous.
Line up the crankshaft and camshaft properly, get cylinder 1 to TDC compression, and go from there.
As long as your distributor is OK and the carburetor works, the engine should run well enough to allow you to do more troubleshooting and adjusting.
It may be worthwhile, if you still have the parts around, to put the points back in to get it running-with points you can see if things are adjusted properly.
You may have complicated your situation by changing so many things at once rather than working it out a step at a time.

[Beardlife]

The old distributor is unfortunately long gone, sent to the great rebuilder in the sky. I peered down the distributor hole to see if the cam had walked forward (can it, even?) and noticed the oil pump drive was gone. it's clanking around the pan right now, I'll have to pull it to fish that out. It'll be a little while before I can get back to diagnosis.

[71Fe2O3]

Don't you just love it when a project expands to frustrate you and eat up your time and money?
On the positive side, you get through it, and you learn something.

[colnago]

When I installed a Pertronix years ago, I made the mistake of pushing the ring with magnets down all the way on the distributor shaft. Found out later that it was so low, the sensor never saw the magnets, so the system never fired. I pulled the ring up on the shaft so the top of the ring was level with the top of the sensor. Ran fine after that. You probably still have cam alignment issues, but I'm wondering if you're having spark issues, too.

Joseph

[Beardlife]

I found that I have a hydraulic cam, with return springs in the lifters. they didnt show play, but without oil pressure, they had about .2 inches less lift. I'll put an oil pump drive in tomorrow hopefully, and see how it rebounds. I already planned on stroking this motor, I'm just hoping not to do it till next summer.

[Beardlife]

My motor started a fain intermittent knocking a couple hundred miles in. It wasn't all the time, but I ended up finding a core 390 that I got rebuilt. On teardown I found mostly sludge, but some small pieces of bearing material. I still think it's possible it could have lasted the winter for me, but as it'll be my daily when it's raining, I decided to just bite the bullet. That was an expensive mistake, but at least this way I get to put in the motor I want. 9.5/1 compression, 4bbl, headers, and an RV cam. Should scoot a bunch better.

[1972hiboy]

My motor started a fain intermittent knocking a couple hundred miles in. It wasn't all the time, but I ended up finding a core 390 that I got rebuilt. On teardown I found mostly sludge, but some small pieces of bearing material. I still think it's possible it could have lasted the winter for me, but as it'll be my daily when it's raining, I decided to just bite the bullet. That was an expensive mistake, but at least this way I get to put in the motor I want. 9.5/1 compression, 4bbl, headers, and an RV cam. Should scoot a bunch better.

so you pulled the 360 or your going to pull the 360? Did you ever get it to run decent enough to drive around?

[Beardlife]

yeah, it drove fine. tear down showed some bearing material in the screen though. i definitely damaged it, but i'm really surprised how tough that motor was.