["QUICK-SILVER"]

Originally Posted by panhead59

I'll check all that is mentioned. Tks for hanging in there. If all this fails, i'll put points back in and try it. Tks again.

Points may not work either, if the ground wire for the base plate got burned up when 12 volt cranking power was hooked to coil negative terminal.

Base plate needs more than friction ground for the coil to fire strong and consistant.

Clay

["QUICK-SILVER"]

Besides base plate ground, the distributor itself needs to be grounded good.

Excess paint on block and hold down clamp makes power hunt ground through moving parts inside the engine. And that's not good.

Distributor ground needs to be just as strong as power supply feeding the ignition system.

With a bad distributor ground, coil spark will come and go. Coil will fire when ground gets broke, which makes for a spark not triggered by points or ignitor. That will make back-fire and wheezing noises like ignition timing is off or cam timing is off.

Clay

ps. Any chance this engine has a multi keyway timing set?

[panhead59]

Yes i believe there were 3 grooves in crank pulley. Its a 1971 455 engine. I remember setting both gears timing marks at 12 oclock. Checked/confirmed at time of install with straight edge. That would be position for fire on #1 comp. Stroke. Correct ? And 12 crank, 6 cam positions are in position for #6 fire on its comp. Stroke. Correct ? So does crank gear have more than 1 timing mark ? One for each key way groove ? If so, its high time i remove timing cover to confirm !

[panhead59]

I have checked ohms from base plate in dist. To batt. Grd. Meter went straight to zero as it should
Correct ? That should prove good grd. Shouldn 't it ?

["QUICK-SILVER"]

Three keyways and three corresponding dots.

Got what's called 'straight up' and then plus or minus a few degrees. A few degrees ain't much when you're turning the crank. Wrong dots and slots (mixed up) can get valve events way off.

If it is way off, you will probably here unusual pumping/sucking noises when you spin the engine with the starter.

This can be checked without pulling the timing cover. By looking at valve events at TDC of the exhaust stroke.

Clay

[pokey1]

Originally Posted by panhead59

Yes i believe there were 3 grooves in crank pulley. Its a 1971 455 engine. I remember setting both gears timing marks at 12 oclock. Checked/confirmed at time of install with straight edge. That would be position for fire on #1 comp. Stroke. Correct ? And 12 crank, 6 cam positions are in position for #6 fire on its comp. Stroke. Correct ? So does crank gear have more than 1 timing mark ? One for each key way groove ? If so, its high time i remove timing cover to confirm !

If I am reading this right I think you have it backwards....crank at 12 and cam at 6 would be number 1 timing mark....

["QUICK-SILVER"]

Originally Posted by panhead59

I have checked ohms from base plate in dist. To batt. Grd. Meter went straight to zero as it should
Correct ? That should prove good grd. Shouldn 't it ?

Yes that sounds good. As long as nothing changes when you wiggle the base plate.

Clay

[panhead59]

As i have mentioned, it does sound weird when cranking. I'll look closely at valve movement while wife cranks it over. What would be a sign valve timing is off ? What do i look for ?

["QUICK-SILVER"]

Originally Posted by pokey1

If I am reading this right I think you have it backwards....crank at 12 and cam at 6 would be number 1 timing mark....

Pontiac is both dots up for #1. Doesn't matter much with dots together...One turn of the crank gets the dots where they belong.

Clay

["QUICK-SILVER"]

Originally Posted by panhead59

As i have mentioned, it does sound weird when cranking. I'll look closely at valve movement while wife cranks it over. What would be a sign valve timing is off ? What do i look for ?

TDC exhaust stroke both valves will be barely open. Intake opens as the piston comes up and exhaust closes as the piston starts down. That space, with both open, is called overlap.

Need to turn the crank by hand to check this.

Clay

[panhead59]

Ok i'll ckeck this in the morning. (Wed). I should have a couple hrs. To work on this
Tks again for everyone's help. I know this is getting old ! B E L I E V E M E !!!

["QUICK-SILVER"]

If you used a wrong keyway with the zero dot...One of two things will happen while looking at valve overlap. The overlap event will happen 120° before TDC or 120° after TDC. That's approximate not exact. The keyways are close to 120° apart.

Clay

[Schurkey]

Originally Posted by panhead59

its high time i remove timing cover to confirm !

Sure, you can take stuff apart, break the gasket seal, spend hours in disassembly and then reassembly. Or you can screw a compression tester into the #1 plug hole, open the throttle, have someone crank the engine, and see if you have reasonable cranking compression pressure.

Pressure varies with altitude, cranking speed, (battery condition) cam grind and timing, and a bunch of other factors. Around here, ~150 psi is pretty common. 130 is low, 165 is high (for these older engines with reasonably stock compression ratios and cam timing.) Adjust as needed based on your experience with other, similar engines at your altitude.

If you have 1. reasonable compression, 2. a burnable fuel mixture, 3. Spark ACROSS THE PLUG GAP at the right time, and 4. a low-restriction exhaust system, the engine should run. "I" would be less concerned about cam timing if the compression pressure measures up. YES, there "could" still be a problem...but it'd likely show up as "poor power" or detonation rather than "no start".

Originally Posted by "QUICK-SILVER"

TDC exhaust stroke both valves will be barely open. Intake opens as the piston comes up and exhaust closes as the piston starts down. That space, with both open, is called overlap.

Need to turn the crank by hand to check this.

ALSO good advice that needs a minimum of disassembly to inspect.

[mgarblik]

Well now that you have mentioned you have a 3 keyway timing set, things get a lot more complicated. You basically have 3 possible keyways to use and 3 separate timing marks. There is 1 correct way to set it up and 8 ways to do it wrong!. I have attached general instructions from Cloyes for reference. What I do makes it nice and simple. Choose the keyway you want to use. Zero, advanced, or retarded. Then chose the corresponding tooth mark for the proper keyway. MARK THEM BOTH WITH A SHARPIE. Now install with your sharpie mark crank tooth at 12:00 and the cam gear tooth mark at 6:00. Verify with straight edge. Your done. When you turn the crank 1 roitation, the cam tooth mark will be at 12:00. Doesn't matter. It's just easier to see tooth to tooth than 12:00-12:00. The engine doesn't know the difference. Good luck.
https://cloyes.com/wp-content/upload...ns-general.pdf

[panhead59]

Yes mgarblik i looked at cloyes video recently. Good info. I'll observe valve movement as these other guys have mentioned. Those results will dictate whether timing cover needs to come off. In a way. I hope not, but that'll mean i haven't found the problem. Plus, i'll check comp. With gauge as suggested.

[panhead59]

IF i have to remove timing cover, what's a good way to stop engine from turning over while removing crankshaft pulley nut. I usually stop it back by flywheel but now i obviously don't have access to that area.

["QUICK-SILVER"]

Originally Posted by panhead59

IF i have to remove timing cover, what's a good way to stop engine from turning over while removing crankshaft pulley nut. I usually stop it back by flywheel but now i obviously don't have access to that area.

Piece of pipe on a 1/2" pull-handle and let the starter break the bolt loose.

That or get two valves closed (back rockers off) and feed a piece of rope down a sparkplug hole.

Starter breaks it loose....Rope locks it up

Clay

[panhead59]

Thank you.

[Gary H]

Clamp two vise grip pliers on the flexplate right beside each other. When you turn the engine to break the balancer bolt loose they will stop it from turning.

[panhead59]

Its a 4 spd and u can't access flywheel. I'll try the starter method i guess