Timing mark out 180 degrees
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Forget about the cam, pull it out and put it on the bench.
Just the crank and pistons, heck, take out all the pistons except #1
Spin the crank until the piston is at the top. Stop there.
That can only be one of two events
1.. Compressed and ready to fire
2.. Done pushing the exhausted fuel out
Rotate the crank one turn and it's back to the top again doing the other thing, but it's still at the top.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Hint: When #6 fires, the crankshaft will be 360 deg from when #1 fires. The info from the op is conflicting. If the timing mark is 180 deg off when the light is hooked up near the #1 plug, then he states it is correct when hooked up to #6, this is the conflict. I suspect he had the light hooked up to #4 or #7 when the mark was in the correct location.
If I'm wrong please explain it to me ,it would'nt be the first time.
If I'm wrong please explain it to me ,it would'nt be the first time.
Perhaps you would like to answer a question.
How can a slipped balancer show 10° advance on #6?
I can't believe I'm getting sucked back in here
Forget about the cam, pull it out and put it on the bench.
Forget about the gears, put them on the bench.
Forget about the distributor, on the bench.
Just the crank and pistons, heck, take out all the pistons except #1
Spin the crank until the piston is at the top. Stop there.
That can only be one of two events
1.. Compressed and ready to fire
2.. Done pushing the exhausted fuel out
Rotate the crank one turn and it's back to the top again doing the other thing, but it's still at the top.
Everyone can agree on that, one turn of the crank = one trip down and up, the piston back to the top
Now put the balancer on.
Chev used 2 balancers, (maybe 3 not sure) most were timed at about the 1-2 o-clock location, I think some of the 305 were at the 12 o-clock, the timing tabs were different.
Even if it was the wrong tab it's somewhere around 12 to 2 o-clock
Lets go with it being the right one for a 350 and put it around 2 o-clock
The keyway on the crank located the harmonic balancer in only 1 place and one place only (key pretty much points at the mark).
The timing line is at 0 when the piston is at the top, regardless of what it's doing there
One trip around is still one trip down and back up. That line has to be on the tab when the piston is at the top.
Put the cam in, either right or 180 out, really it doesn't matter. Pick whichever you want.
Put in the distributor with it ready to fire Number #1
Maybe we are right, maybe we are out 180 on the dist. Doesn't matter.
Hook up the timing light to #1 wire.
Spin the engine over, #1 gets juice, light comes on.
Either it's right and the piston has compressed the fuel. Piston is at the top, line is on the tab
Or it's wrong, exhaust stroke just finishing. Piston is still at the top, line is still on the tab
Regardless of the cam being right or out 180, and regardless of the distributor orientation, when #1 fires, #1 piston has to be at the top, line has to be on the tab (or out a few inches if it's the wrong balancer)
If it's way out (180)
No key in the crank/balancer (possible, seems unlikely)
Outer ring on the balancer spun (probable, happens to lots of people, (not me personally) , especially if the engine has seen some higher rpms')
Now maybe there is some aftermarket balancer with different or multiple keyways. Maybe some aftermarket crank with the key somewhere else for some reason. I don't know.
All of this is based on regular GM stuff
Mooser
Forget about the cam, pull it out and put it on the bench.
Forget about the gears, put them on the bench.
Forget about the distributor, on the bench.
Just the crank and pistons, heck, take out all the pistons except #1
Spin the crank until the piston is at the top. Stop there.
That can only be one of two events
1.. Compressed and ready to fire
2.. Done pushing the exhausted fuel out
Rotate the crank one turn and it's back to the top again doing the other thing, but it's still at the top.
Everyone can agree on that, one turn of the crank = one trip down and up, the piston back to the top
Now put the balancer on.
Chev used 2 balancers, (maybe 3 not sure) most were timed at about the 1-2 o-clock location, I think some of the 305 were at the 12 o-clock, the timing tabs were different.
Even if it was the wrong tab it's somewhere around 12 to 2 o-clock
Lets go with it being the right one for a 350 and put it around 2 o-clock
The keyway on the crank located the harmonic balancer in only 1 place and one place only (key pretty much points at the mark).
The timing line is at 0 when the piston is at the top, regardless of what it's doing there
One trip around is still one trip down and back up. That line has to be on the tab when the piston is at the top.
Put the cam in, either right or 180 out, really it doesn't matter. Pick whichever you want.
Put in the distributor with it ready to fire Number #1
Maybe we are right, maybe we are out 180 on the dist. Doesn't matter.
Hook up the timing light to #1 wire.
Spin the engine over, #1 gets juice, light comes on.
Either it's right and the piston has compressed the fuel. Piston is at the top, line is on the tab
Or it's wrong, exhaust stroke just finishing. Piston is still at the top, line is still on the tab
Regardless of the cam being right or out 180, and regardless of the distributor orientation, when #1 fires, #1 piston has to be at the top, line has to be on the tab (or out a few inches if it's the wrong balancer)
If it's way out (180)
No key in the crank/balancer (possible, seems unlikely)
Outer ring on the balancer spun (probable, happens to lots of people, (not me personally) , especially if the engine has seen some higher rpms')
Now maybe there is some aftermarket balancer with different or multiple keyways. Maybe some aftermarket crank with the key somewhere else for some reason. I don't know.
All of this is based on regular GM stuff
Mooser
The question now is whether or not it truly was timed using #6 or a slipped ring.
Could it be both, possible, hope he got the lottery ticket.
Guess we'll have to wait for the OP for new observations.
He can just pull the crank bolt alone to confirm the keyway vs the balancer mark.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
rotate the engine till you're on tdc compression stroke for #1, pull the cap, if the rotor is pointing at #6, that means you have the #1 plug wire attached to the cap in the #6 post. lift the distributor and rotate the rotor to where #1 should be (directly across from #6. pull your distributor wires and using the new #1 position, re-attach the wires in the correct firing order starting with #1's new position. I know that sounds to simple, but it works. hope this helps
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
mike...
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
This mind teaser is wild have we all over thought this issue ? . What location on cap is the number wire ? Is it pointing at number 1 cylinder ?
I just ran a light on my sb, the tdc mark is approx at 12 o'clock on mine as i am set with initial advance as all of us are. . If I put light on number 6 ,I can not see the mark because it would be at 6 o'clock, Additionally if I set my timing to tdc the mark moves to approx 2 o'clock . I would then have 6 firing with the mark at 7 o'clock again nothing I can see with my light unless I want to lay under car.
I agree the balancer has slipped , because of a few things .
One he stated original oem no mods except carb jets and headers and dual exhaust no head , lower end or cam work done to it.
and secondly If he can see timing marks from opposite side ( pass side ) he is no where close to 180 out .
I would pull number 1 wire , crank engine and stop when #1 sparks. Then pull cap and see where rotor is located if it is pointing towards number 1 cyl as it should be then replace the ballancer .
I just ran a light on my sb, the tdc mark is approx at 12 o'clock on mine as i am set with initial advance as all of us are. . If I put light on number 6 ,I can not see the mark because it would be at 6 o'clock, Additionally if I set my timing to tdc the mark moves to approx 2 o'clock . I would then have 6 firing with the mark at 7 o'clock again nothing I can see with my light unless I want to lay under car.
I agree the balancer has slipped , because of a few things .
One he stated original oem no mods except carb jets and headers and dual exhaust no head , lower end or cam work done to it.
and secondly If he can see timing marks from opposite side ( pass side ) he is no where close to 180 out .
I would pull number 1 wire , crank engine and stop when #1 sparks. Then pull cap and see where rotor is located if it is pointing towards number 1 cyl as it should be then replace the ballancer .
Thread Starter
Racer
Joined: Jun 2012
Posts: 283
Likes: 24
From: Berlin Township oh
Patience weed hopper, it is Mid june in ohio and i am tied up driving and looking at cars this weekend. So far this weekend we had the national Cobra meet, Mid Ohio Vintage days, Cobra autocross today and 2 cruise ins. doesnt leave much time to tinker in the garage, does it?
I can tell you this the number 1 wire is located at the front of the cap and firing order is correct. yes i know that the 1 plug is located at the front left head and that the plugs are odd on the left and even on the right. i do own a manual and do read it prior to reaching out. This is not my first rodeo either. i have owned numerous chevy products with HEI ignition over my 50 years on this planet, this is the first vehicle i have owned where i put the timing light on the #1 plug and couldnt see the timing mark and the engine ran fine. i have put probably 500 miles on it since i got done painting it and it runs great.
But, you will have to wait for pictures, until i get time to take them and post them, so please have patience
I can tell you this the number 1 wire is located at the front of the cap and firing order is correct. yes i know that the 1 plug is located at the front left head and that the plugs are odd on the left and even on the right. i do own a manual and do read it prior to reaching out. This is not my first rodeo either. i have owned numerous chevy products with HEI ignition over my 50 years on this planet, this is the first vehicle i have owned where i put the timing light on the #1 plug and couldnt see the timing mark and the engine ran fine. i have put probably 500 miles on it since i got done painting it and it runs great.
But, you will have to wait for pictures, until i get time to take them and post them, so please have patience
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
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Thread Starter
Racer
Joined: Jun 2012
Posts: 283
Likes: 24
From: Berlin Township oh
if you have never been to the cobra meet, you need to put it on your list. around 500 cobras of all types. the town of London Ohio hosts it and they realy know how to put on a good time. On Saturday, they shut down Main street for about a 1/2 mile and for a $10.00 donation to Cystic Fibrosis, you can jump in a Cobra passenger seat and go for a 1/4 mile pass right down main street. very cool. They usualy raise 20-30 K on a saturday. it is not uncommon for folks to drop 100 buck on 10 rides and a row. Very good time, the sweet smell of racing fuel and burning rubber
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
Patience weed hopper, it is Mid june in ohio and i am tied up driving and looking at cars this weekend. So far this weekend we had the national Cobra meet, Mid Ohio Vintage days, Cobra autocross today and 2 cruise ins. doesnt leave much time to tinker in the garage, does it?
I can tell you this the number 1 wire is located at the front of the cap and firing order is correct. yes i know that the 1 plug is located at the front left head and that the plugs are odd on the left and even on the right. i do own a manual and do read it prior to reaching out. This is not my first rodeo either. i have owned numerous chevy products with HEI ignition over my 50 years on this planet, this is the first vehicle i have owned where i put the timing light on the #1 plug and couldnt see the timing mark and the engine ran fine. i have put probably 500 miles on it since i got done painting it and it runs great.
But, you will have to wait for pictures, until i get time to take them and post them, so please have patience
I can tell you this the number 1 wire is located at the front of the cap and firing order is correct. yes i know that the 1 plug is located at the front left head and that the plugs are odd on the left and even on the right. i do own a manual and do read it prior to reaching out. This is not my first rodeo either. i have owned numerous chevy products with HEI ignition over my 50 years on this planet, this is the first vehicle i have owned where i put the timing light on the #1 plug and couldnt see the timing mark and the engine ran fine. i have put probably 500 miles on it since i got done painting it and it runs great.
But, you will have to wait for pictures, until i get time to take them and post them, so please have patience
Where do I say go and work on car ? HOW ABOUT thanking people for even offering any advice ???
I am usually a helpful guy to the point i even went out and put a light on my own vette ,, at this point you need to go try things not post with your weekend travel events . And by the way your 50 years and numerous Chevy experiences means nothing to anyone but you at this point.
And on your way home from work one day this week pick up a new balancer.
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
" Patience weed hopper " really that is how he replies to my post of help and advice > I am a weed hoppper ? And then you come by to point out my comments >?? Are you a democrat ? Or liberal ?? ha ha ha ha ha ha ha ha ha ha I am joking of course but really he had no reason to reply except to take a jab at me ..
I do agree people could be nicer
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
I never said you did , he took a jab at me which i replied to , and thanking others is fine and there was no need to cut me off at the knees for offering advice even if you dont like it , the mirror is all his to look at .
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
If you will put the light on #6 you will see that the mark lines up the same as #1. As the crankshaft turns and fires on #1 at say 16 deg btc, then turns 1/4 turn then fires on #8 and so on. At one full turn from #1, #6 fires, then one full turn later, #1 again. So you see, you will get the same timing light results hooked up to 1 or 6.
Racer
Joined: Jun 2011
Posts: 383
Likes: 21
From: Greenville Ohio
London, Ohio? I've been to London numerous times and would never have thought they would put something like a Cobra meet on. Sounds cool though. What they need to do is hook up with the law enforcement training center in London and use thier high speed track.
Drifting
Joined: Nov 2003
Posts: 1,874
Likes: 7
From: l In
Safety Car
Joined: Sep 2007
Posts: 4,458
Likes: 331
From: Indy Indiana
ok, late coming into this thread..
1. I like the lottery statement, there is no way that a balancer would have spun exactly 180 degrees and stayed there, throw that theory out. if it has spun 180, then 4 and 7 would line up with the mark.. not 6.
2. all these chevy engines have cyl 1 and cyl 6 at tdc the same time. they are companion cylinders, 1 is at top of compression stroke while 6 is top of exhaust stroke, but both are at tdc. if you place your pickup on either 6 or 1 the lite would trigger at the same marking. everyone go put your pickup on #6 and you will see. if the balancer had spun, then 6 would be wrong too. the light will flash only on every other pass across the marker. one spark per 2 revolutions of the crank ( 4-stroke theory). the companion cyl ( 6) will spark at the marker on the next revolution of the crank.
3. the OP states that the light is correct on 6 but is 180 off on 1. no way this can happen and still be firing on all 8 correctly.
4. 1 is 180 off, then it is firing when either 4 or 7 is at tdc 180 degrees later, and 4 or 7 is firing when 1 should. 1 8 4 3 6 5 7 2 all are at tdc 90 degrees apart . 8 X 90 = 720 total degrees = 2 revolutions ( 4-stroke theory). irregardless of cam timing, 1 cannot be wrong and 6 be right. this engine is running at best only on 6 cylinders because 2 are plugged in wrong.
you can play games with your cam setup 180 off then correct it with having #1 on your cap at 180 off ( remember, the rotor spins at cam speed), but still 1 and 6 are at tdc. you can spark on the top of your your exhaust stroke but it won't produce any power. and it will be 360 degrees off not 180.
either the OP is wrong on his pickup location or this engine is running at best on 6 cylinders. the firing order is wrong on the cap. 1 cannot be wrong and 6 right, they are either both wrong or both right.
trace the wiring.. drivers side cylinders are 1 3 5 7 front to back, passenger side is 2-4-6-8 front to back. the marker lining up on cyl 6 proves that there is no spun balancer.
1. I like the lottery statement, there is no way that a balancer would have spun exactly 180 degrees and stayed there, throw that theory out. if it has spun 180, then 4 and 7 would line up with the mark.. not 6.
2. all these chevy engines have cyl 1 and cyl 6 at tdc the same time. they are companion cylinders, 1 is at top of compression stroke while 6 is top of exhaust stroke, but both are at tdc. if you place your pickup on either 6 or 1 the lite would trigger at the same marking. everyone go put your pickup on #6 and you will see. if the balancer had spun, then 6 would be wrong too. the light will flash only on every other pass across the marker. one spark per 2 revolutions of the crank ( 4-stroke theory). the companion cyl ( 6) will spark at the marker on the next revolution of the crank.
3. the OP states that the light is correct on 6 but is 180 off on 1. no way this can happen and still be firing on all 8 correctly.
4. 1 is 180 off, then it is firing when either 4 or 7 is at tdc 180 degrees later, and 4 or 7 is firing when 1 should. 1 8 4 3 6 5 7 2 all are at tdc 90 degrees apart . 8 X 90 = 720 total degrees = 2 revolutions ( 4-stroke theory). irregardless of cam timing, 1 cannot be wrong and 6 be right. this engine is running at best only on 6 cylinders because 2 are plugged in wrong.
you can play games with your cam setup 180 off then correct it with having #1 on your cap at 180 off ( remember, the rotor spins at cam speed), but still 1 and 6 are at tdc. you can spark on the top of your your exhaust stroke but it won't produce any power. and it will be 360 degrees off not 180.
either the OP is wrong on his pickup location or this engine is running at best on 6 cylinders. the firing order is wrong on the cap. 1 cannot be wrong and 6 right, they are either both wrong or both right.
trace the wiring.. drivers side cylinders are 1 3 5 7 front to back, passenger side is 2-4-6-8 front to back. the marker lining up on cyl 6 proves that there is no spun balancer.
Melting Slicks
Joined: Mar 2007
Posts: 2,520
Likes: 11
From: Hinckley OH
ok, late coming into this thread..
1. I like the lottery statement, there is no way that a balancer would have spun exactly 180 degrees and stayed there, throw that theory out. if it has spun 180, then 4 and 7 would line up with the mark.. not 6.
2. all these chevy engines have cyl 1 and cyl 6 at tdc the same time. they are companion cylinders, 1 is at top of compression stroke while 6 is top of exhaust stroke, but both are at tdc. if you place your pickup on either 6 or 1 the lite would trigger at the same marking. everyone go put your pickup on #6 and you will see. if the balancer had spun, then 6 would be wrong too. the light will flash only on every other pass across the marker. one spark per 2 revolutions of the crank ( 4-stroke theory). the companion cyl ( 6) will spark at the marker on the next revolution of the crank.
3. the OP states that the light is correct on 6 but is 180 off on 1. no way this can happen and still be firing on all 8 correctly.
4. 1 is 180 off, then it is firing when either 4 or 7 is at tdc 180 degrees later, and 4 or 7 is firing when 1 should. 1 8 4 3 6 5 7 2 all are at tdc 90 degrees apart . 8 X 90 = 720 total degrees = 2 revolutions ( 4-stroke theory). irregardless of cam timing, 1 cannot be wrong and 6 be right. this engine is running at best only on 6 cylinders because 2 are plugged in wrong.
you can play games with your cam setup 180 off then correct it with having #1 on your cap at 180 off ( remember, the rotor spins at cam speed), but still 1 and 6 are at tdc. you can spark on the top of your your exhaust stroke but it won't produce any power. and it will be 360 degrees off not 180.
either the OP is wrong on his pickup location or this engine is running at best on 6 cylinders. the firing order is wrong on the cap. 1 cannot be wrong and 6 right, they are either both wrong or both right.
trace the wiring.. drivers side cylinders are 1 3 5 7 front to back, passenger side is 2-4-6-8 front to back. the marker lining up on cyl 6 proves that there is no spun balancer.
1. I like the lottery statement, there is no way that a balancer would have spun exactly 180 degrees and stayed there, throw that theory out. if it has spun 180, then 4 and 7 would line up with the mark.. not 6.
2. all these chevy engines have cyl 1 and cyl 6 at tdc the same time. they are companion cylinders, 1 is at top of compression stroke while 6 is top of exhaust stroke, but both are at tdc. if you place your pickup on either 6 or 1 the lite would trigger at the same marking. everyone go put your pickup on #6 and you will see. if the balancer had spun, then 6 would be wrong too. the light will flash only on every other pass across the marker. one spark per 2 revolutions of the crank ( 4-stroke theory). the companion cyl ( 6) will spark at the marker on the next revolution of the crank.
3. the OP states that the light is correct on 6 but is 180 off on 1. no way this can happen and still be firing on all 8 correctly.
4. 1 is 180 off, then it is firing when either 4 or 7 is at tdc 180 degrees later, and 4 or 7 is firing when 1 should. 1 8 4 3 6 5 7 2 all are at tdc 90 degrees apart . 8 X 90 = 720 total degrees = 2 revolutions ( 4-stroke theory). irregardless of cam timing, 1 cannot be wrong and 6 be right. this engine is running at best only on 6 cylinders because 2 are plugged in wrong.
you can play games with your cam setup 180 off then correct it with having #1 on your cap at 180 off ( remember, the rotor spins at cam speed), but still 1 and 6 are at tdc. you can spark on the top of your your exhaust stroke but it won't produce any power. and it will be 360 degrees off not 180.
either the OP is wrong on his pickup location or this engine is running at best on 6 cylinders. the firing order is wrong on the cap. 1 cannot be wrong and 6 right, they are either both wrong or both right.
trace the wiring.. drivers side cylinders are 1 3 5 7 front to back, passenger side is 2-4-6-8 front to back. the marker lining up on cyl 6 proves that there is no spun balancer.
Good post. You are absolutely correct about 1 and 6 being at TDC at the same time and the timing mark will be either correct or incorrect on both. I should have thought of that.
Pro
Joined: Sep 2002
Posts: 624
Likes: 1
From: Melbourne, Fla. 6 months- New Middletown, Ohio 6 months
Over the years I cannot remember how many times I have seen someone align the dots on the crank and cam gears with the crank at 12 o'clock and the cam a 6 o'clock. After that they install the distributor pointing at number one and try to start the car only to have it backfire. They then bring the mark up to TDC watching the rockers on #1, remove the cap and and wonder why they somehow were on number 6, 180 degrees out. They move the distributor to number one and all is well. Why did they make the mistake, because Putting the dots together is the way you always setup a SBC.....Well, not exactly. And they will probably make the same mistake and the same fix down the road and never think twice about it.
Putting the two dots together does just seem logical but not correct!!!
Putting the two dots together does just seem logical but not correct!!!
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Putting the dots together provides a simple, accurate visual reference to ensure the cam timing is right on. If the builder's not going to degree the cam - and most new builders don't - it's better than trying to visually align the dots at 12 and 12 and maybe ending up a tooth off.
It's simple enough to set the engine to TDC compression #1 after the valve adjustment is done...new builders just forget
It's simple enough to set the engine to TDC compression #1 after the valve adjustment is done...new builders just forget