Timing mark out 180 degrees
06-22-2012, 07:21 PM
#41
Le Mans Master
I think everyone's made their observations about what the issue is, and I addressed this in my comments. We all seem to have a different take on what's happening.
I think everyone would agree that an hour's investment in troubleshooting to see if the issue can be resolved simply is better than just diving in and pulling the balancer and the front cover, fair? If what I suggested doesn't work then the more invasive troubleshooting can go from there. Worst case, wasted hour
I think everyone would agree that an hour's investment in troubleshooting to see if the issue can be resolved simply is better than just diving in and pulling the balancer and the front cover, fair? If what I suggested doesn't work then the more invasive troubleshooting can go from there. Worst case, wasted hour
#1 cannot fire at BDC, and this is what the timing light is saying is happening. There is no other explanation other than the balancer has spun.
06-22-2012, 07:27 PM
#42
Le Mans Master
I can certainly answer your question, and have - see my comment regarding companion cylinders and the relationship to cam timing. You might not agree that it's an answer, or that it's common sense - but there's my answer.
The OP is a smart guy and has all the recommendations - he can decide what he wants to do.
Last edited by billla; 06-22-2012 at 07:30 PM.
06-22-2012, 07:46 PM
#43
Le Mans Master
06-22-2012, 08:55 PM
#44
Race Director
Should I let this go on. 
You guys have me busting a gut here
The OP has already answered this for ya.
Hint #1- The balancer has not slipped
Hint #2- When #6 fires on the compression stroke, where is the crank key/balancer mark?
You guys have me busting a gut here
The OP has already answered this for ya.
Hint #1- The balancer has not slipped
Hint #2- When #6 fires on the compression stroke, where is the crank key/balancer mark?
06-22-2012, 09:07 PM
#45
Racer
Thread Starter
Very good, again thanks for all the tips. tomorrow is the cobra show then familiy obligations. Sunday i am wide open, so i will do some tinkering on marking number 6 TDC and switching out the dizzy to number 1 to see what happens. I will make sure to take pictures and report back.
Thanks again guys!
Thanks again guys!
06-22-2012, 09:25 PM
#48
Race Director
Very good, again thanks for all the tips. tomorrow is the cobra show then familiy obligations. Sunday i am wide open, so i will do some tinkering on marking number 6 TDC and switching out the dizzy to number 1 to see what happens. I will make sure to take pictures and report back.
Thanks again guys!
Thanks again guys!
As far as the rusted weights etc, carefully take things apart and clean them up, then lube the pins with a very little bit of points grease so they move freely. If they don't move freely, your timing advance is not working correctly.
OP said when he uses #6 wire with the lite, the marks show correctly.
Have a look at this diagram.
06-22-2012, 09:43 PM
#50
Le Mans Master
06-22-2012, 10:00 PM
#51
Race Director
06-22-2012, 10:07 PM
#53
Le Mans Master
06-22-2012, 10:13 PM
#54
Race Director
06-22-2012, 10:18 PM
#55
Le Mans Master
06-22-2012, 10:39 PM
#56
Le Mans Master
If the op listens to half the posters here, it won't even run when he's done the suggested repairs. Use common sense, the engine runs good now, when time permits, replace the ballancer. Some are overthinking the problem and getting confused. It's merely a coincenince that the ballancer happened to slip 180 deg.
06-22-2012, 11:10 PM
#57
Race Director
First of all, i have been lurking here for about 3 weeks learning about my 1978 corvette that i am just getting back out on the road after painting the body and redoing the interior for the last year.
This is a great resource and i thank the admin folks for a terrific site.
In reading this site i decided to move ahead with a timing advance curve kit. I purchased, cap, rotor, wires, coil, plugs and advanced kit. I figured i would check the timing, vacuum and idle before tearing into it.
My car is a l48 350 auto, pretty much all stock except for headers and a true dual exhaust. i did have my carb rejetted do to the new exhaust. the car starts, runs smoothly at all rpms and also starts fine warm, no pinging.
Back to the issue, when i took a reading of the timing with the vacuum disconnected and plugged at the advance can, i could not see the timing mark. i shut her down, rotated the crank and cleaned off the timing mark and put a dab of yellow paint on the groove. Started the engine back up and still couldn't see the timing mark. if i move the timing gun over to the right side of the motor, i can see the timing mark. It is like it is out by 180 degrees. i am sure i have the inducter on spark plug #1, the first plug on the left side, what could i be missing to get my tinming mark back to the timing tag? Thanks in advance!
This is a great resource and i thank the admin folks for a terrific site.
In reading this site i decided to move ahead with a timing advance curve kit. I purchased, cap, rotor, wires, coil, plugs and advanced kit. I figured i would check the timing, vacuum and idle before tearing into it.
My car is a l48 350 auto, pretty much all stock except for headers and a true dual exhaust. i did have my carb rejetted do to the new exhaust. the car starts, runs smoothly at all rpms and also starts fine warm, no pinging.
Back to the issue, when i took a reading of the timing with the vacuum disconnected and plugged at the advance can, i could not see the timing mark. i shut her down, rotated the crank and cleaned off the timing mark and put a dab of yellow paint on the groove. Started the engine back up and still couldn't see the timing mark. if i move the timing gun over to the right side of the motor, i can see the timing mark. It is like it is out by 180 degrees. i am sure i have the inducter on spark plug #1, the first plug on the left side, what could i be missing to get my tinming mark back to the timing tag? Thanks in advance!
To some posters, thank you for your insightful comments, to others, make sure to stop by the pill cart when it comes around.
I fired her up this afternoon and got out my timing light. Idle is at 600 or so with the vacuum can disconnected. i moved the pickup around to each spark plug and sure enough, # 6 wire is where i get my timing mark to line up. I have about 10 dgrees timing right now. i poped the cap off and if i line up the timing mark to TDC, the rotor points to number 6 wire. very interesting! The strange thing is that the motor runs great, easy starts both cold and warm, no detonation and my plugs are a nice tan color. If the cam is out 180, i think i will just leave it untill winter, it has only been this way for the last 4 years i have had the car, Maybe if i get rambuctious, i will pop off the main drive pully and check the dampner,
I dont claim to be an expert by any means, but i didnt think the engine would run that well with the cam out 180 degrees
I fired her up this afternoon and got out my timing light. Idle is at 600 or so with the vacuum can disconnected. i moved the pickup around to each spark plug and sure enough, # 6 wire is where i get my timing mark to line up. I have about 10 dgrees timing right now. i poped the cap off and if i line up the timing mark to TDC, the rotor points to number 6 wire. very interesting! The strange thing is that the motor runs great, easy starts both cold and warm, no detonation and my plugs are a nice tan color. If the cam is out 180, i think i will just leave it untill winter, it has only been this way for the last 4 years i have had the car, Maybe if i get rambuctious, i will pop off the main drive pully and check the dampner,
I dont claim to be an expert by any means, but i didnt think the engine would run that well with the cam out 180 degrees
He admits it has run well for 4 years and confirmed accurate timing by #6 cyl.
You choose which reference holds more weight.
After all this is long distance, sight unseen, internet diagnosis.
As mentioned here; and I may add that it is also timed well using #6
06-22-2012, 11:24 PM
#58
Le Mans Master
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.
06-22-2012, 11:39 PM
#59
Le Mans Master
He admits it has run well for 4 years and confirmed accurate timing by #6 cyl. You choose which reference holds more weight.
After all this is long distance, sight unseen, internet diagnosis.
As mentioned here; and I may add that it is also timed well using #6
After all this is long distance, sight unseen, internet diagnosis.
As mentioned here; and I may add that it is also timed well using #6
You still haven"t answered my question.
How #1 cylinder can fire when the piston is at BDC?
06-23-2012, 12:05 AM
#60
Race Director
Member Since: Apr 2011
Location: North of Toronto - Ontario
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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