don71

I can't help much, but will try to show a pic of two dampners with what I believe to be factory markings.



http://imageshack.com/a/img384/6346/...selmarkpx1.jpg

[IMG=http://imagizer.imageshack.us/v2/xq90/384/damperchiselmarkpx1.jpg][/IMG]

don71

Ok, that didn't work so well.

I'll try to show a pic of a badly out of spec slipped dampner looks like.



I know this is confusing. If your efforts to time this thing correctly all add up, then I would still suspect the dampner as a problem. I suspect somebody has been here before, and you are experiencing his problem too. The mark on yours doesn't look right.

oldcutlass

Lets go about this differently, set your total timing to 34 deg's @ 3000 rpm, make sure it does not advance any farther if you raise the rpm's higher. Then set your idle to where it's supposed to be and recheck (do not adjust) where your initial is. Leave the vacuum advance disconnected and capped for now.

Fun71

I just read through this entire post. What I see is the dampener is not in the correct position for the #1 piston being at TDC. The only reason I can see for this is the dampener is not bolted to the crank in its proper position. Eric detailed how things are connected internally, and there is NO WAY the crankshaft can be out of sync with #1 piston at TDC. The conclusion is it must be the dampener is out of position on the crankshaft.

Have you pulled the dampener to verify:
1) it has a key, and
2) it is bolted in the correct orientation?

edit:
I thought of another possibility: If the dampener is bolted up properly, then the timing indicator is lying about where 0º really is.

hullinger

I know i am late to the party but i wanted to share a nearly identical problem I had with a 425 I was working on over the summer. I did everything that was discussed in this thread and a whole lot more, but all to no avail. Finally I connected a vacuum gauge to the intake and read the results. I suspect you'll have similar results as me which were low vacuum and with an erratic flutter. I deducted the problem was too much cam plus wrong valve stem height.

I was still driving the car but I ended up setting the timing using the vacuum gauge instead of the timing light.

Chris

cjsdad

I agree that you need to verify true TDC of your #1 piston. Use a positive stop method that will stop the piston roughly 15 degrees before TDC. A spark plug that has been cored with a bolt in it for example. Turn the crank S-L-O-W-L-Y until it stops against the positive-stop device. Mark the balancer even with the 0 degree mark. Turn the crank backwards S-L-O-W-L-Y until it contacts the positive-stop device again. Mark the balancer even with the 0 degree mark again. True TDC will be half way between those two marks. If the factory mark on the balancer is not accurate you will need to either correct the balancer or replace it. This is a great time to see how much slack you have in your timing set. As mentioned above, 4 to 6 crankshaft degrees should be the maximum.

If you are using a phone camera try to get a pic directly in front of the balancer and see if the keyway slot in the crank snout lines up with the keyway slot in the balancer. Once the balancer is verified correct, set everything to zero on the timing light. You need to verify the baseline advance before turning the **** on the variable light. Disconnect the vacuum advance and start the engine. You should be able to set your initial advance to the factory setting. If you are not getting the desired maximum advance at 3000 RPM, adjust it.

If the vacuum advance canister will not let you turn the distributor to the desired advance, try turning it the other way and move all the plug wires clockwise one position. If this is not a possible solution you will need to pull it out and turn it clockwise one tooth and readjust.

BlackGold

I haven't read this entire thread carefully, but has anyone suggested that he might have the wrong timing tab and/or it might be bolted to the block incorrectly? I'm not saying it would be easy to do so, but it's possible someone kludged it.

rootney

Many setback type timing lights don't work well with MSD ignition systems.
Just tossin it out there.


George

rootney

Many setback type timing lights don't work well with MSD ignition systems.
Just tossin it out there.


George

dc2x4drvr

I'm late to this party, but when I'm using my dial back lt. I check timing using the 0* mark on timing tab, so to check timing, rev motor to 3000 rpm's then move the timing dial till the damper mark is aligned with 0 on the tab, read the value on timing lt dial. Should be around 34-36* with vacuum disconnected.

jpc647

I can't, if I try to time it to those settings, the engine dies or shuts off.


If there is a key-way, how can it be in wrong, or not in the proper position. Doesn't the key way ensure the damper is can only go on one way?

I haven't pulled the damper off yet, but how can it be in the wrong orientation? Like on backwards or something?



Does it matter which port on the intake I connect it to? I've got a vacuum gauge and I can easily check this. I'm assuming the motor has been rebuilt at some point, who knows how long ago.

Can anyone post a picture of their timing tab on a 71-72 350? I asked for this on a different thread a long time ago and I don't remember getting much in the line of replies.


Mine isn't an MSD. It's a GM HEI system, guessing it's out of like a 75 vintage motor. I don't know anything about distributor curves and such, not sure if that could play into this?

That's what I did. But mine is like 55* all in and 36 base.

hullinger

When I connect the vacuum gauge I use the port that feeds the power brakes.

Fun71

Yes, but it works only if there is actually a key in the key-way slot.

Like if there is no key in the slot then the only thing holding the dampener in place is the crank snout bolt. If there isn't a key, the dampener could have slipped on the crank to where it is now in the wrong position.

Forget doing ANYTHING related to what vacuum port is connected, what the total timing should be set to, etc. None of this has any meaning until AFTER you get piston TDC and the dampener zero degree position reconciled. It is all meaningless unless TDC = 0* on the indicator.

nsnarsk65cutlass

Thats what i think.but first i'd check the timing with a different light, new means new not good.

Fun71

I agree that new doesn't always mean good, but remember this post:
This means that for some reason when #1 is at TDC the mark on the dampener doesn't match 0º on the timing tab. There are very few ways for that to occur, and the list of possibilities needs to be checked one by one until the reason is discovered.

sqeeek

Thanks for that, I think that's part of the cause of my similar problem. Using an engine rebuilt by rednecks a couple of decades ago, I think it would probably work great on a tractor but I'm getting sick of not knowing how the heck it was put together.

rjohnson442

put a new zero mark on it at TDC#! and run it see if your numbers match. The has to be at least enough of a key for the timing chain sprocket or it wouldn't run at all. You can pull the valve cover to confirm mechanical timing instead of tearing the front apart just yet.

MDchanic

Technical note:

The square key (not a woodruff key) for the crank sprocket and balancer is an unusually long one.
It would be easy for someone to install a shorter key, which would secure the sprocket, but not the balancer.

In general, most of the time (and specifically in the case of the balancer), a key is there to orient parts during assembly and to prevent rotation while things are tightened up, but does NOT serve to prevent rotation once assembled.
This means that the balancer is probably fixed in its current location, even without a key, and will not move any further.

Of course, the outer ring if the balancer can still slip, but that's another story.

- Eric

tonycpe

a big cam in a low compression motor may need 50 degrees of spark timing to run halfway decent.

oldolds88

just to throw something else out there,are you sure thats an oldsmobile timing tag?

Octania

The timing tab looks correctish to me
I have seen crank keyways wollered out at least that far from running the damper loose.

Boils down to:
quite futzing around and VERIFY YOUR TIMING MARK by means of piston position.

MDchanic

June 19th:

• Quote:

  Originally Posted by jpc647

  Checked the initial timing tonight with the vacuum advance unplugged, base timing is approx 39*. I have to dial it back 27* to get it to the 12* mark on the timing tab. Motor is a 72 350, HEI ignitiion out of what appears to be a newer 76 vintage car.
  
  Around 3800 rpms(timing light calculated), I have to add 43* to make the damper mark hit the 12* mark on the tab, or 55* timing all in.
  
  If I try to dial the initial back to 12/14degrees the engine starts to want to die.

June 20th:

• Quote:

  Originally Posted by oddball

  Something isn't right. It's actually quite hard to start an engine with that much advance - you'll get kickback any time the engine is warm.
  You should verify TDC on the #1 piston with the timing tab and the balancer mark.
• Quote:

  Originally Posted by MDchanic

  Since 39° at idle, 55° at 3800 RPM seems a bit too advanced, the next question is, have you verified that the timing mark on your balancer is accurate?
• Quote:

  Originally Posted by MDchanic

  You have to use a dial indicator, a spark plug hole whistle attachment, or a spark plug base threaded to accept a bolt, to determine within a degree or two when the #1 piston is at top dead center.
  At that point, the line should point to the Zero.
• Quote:

  Originally Posted by MDchanic

  The numbers you are giving for ignition timing do not make sense under the conditions you describe.

June 27th:

• Quote:

  Originally Posted by waterzap

  Did you verify TDC?
  Competition Cams 4795 Top Dead Center Stop, 14mm Bolt-Style : Amazon.com : Automotive

July 2nd:

• Quote:

  Originally Posted by jpc647

  Yes, with a screw driver and then with my finger over the plug hole as mentioned above.

July 3rd:

• Quote:

  Originally Posted by MDchanic

  Yeah, this is starting to look like one of those "that never happens" kind of problems.
  
  Piston is connected to crankshaft by connecting rod.
  Neither piston height nor con rod length can change.
  Crank throw is a certain distance at a certain number of degrees.
  Neither of these can change either, and they didn't make cranks with different angles on the #1 throw.
  Crank is attached to damper with key in keyway.
  Neither crank nor damper was ever made with keyway in a different location (except for 1964 damper, but that one's farther out than yours).
  Since the damper really looks like it hasn't moved, that leaves only one possibility that I can see:
  What if someone installed your damper with only a piece of the key in the keyway (enough to engage the crank gear), then tightened up the damper "close" to its correct position?
  
  Far fetched? Yes, but I can't think of any other cause.
  
  I would strongly recommend using a very accurate method of determining TDC, like a dial indicator or one of those stop bolts adjusted very slightly in, and marking your balancer with the exact TDC, then timing your car like it should be.
  
  After that, I'd pull the balancer for a closer look.

February 12th:

• Quote:

  Originally Posted by jpc647

  I'm really not sure what else I can check.
• Quote:

  Originally Posted by Fun71

  What I see is the dampener is not in the correct position for the #1 piston being at TDC. The only reason I can see for this is the dampener is not bolted to the crank in its proper position. Eric detailed how things are connected internally, and there is NO WAY the crankshaft can be out of sync with #1 piston at TDC. The conclusion is it must be the dampener is out of position on the crankshaft.
  
  Have you pulled the dampener to verify:
  1) it has a key, and
  2) it is bolted in the correct orientation?
• Quote:

  Originally Posted by cjsdad

  I agree that you need to verify true TDC of your #1 piston. Use a positive stop method that will stop the piston roughly 15 degrees before TDC. A spark plug that has been cored with a bolt in it for example. Turn the crank S-L-O-W-L-Y until it stops against the positive-stop device. Mark the balancer even with the 0 degree mark. Turn the crank backwards S-L-O-W-L-Y until it contacts the positive-stop device again. Mark the balancer even with the 0 degree mark again. True TDC will be half way between those two marks. If the factory mark on the balancer is not accurate you will need to either correct the balancer or replace it.
•  
  • Quote:

    Originally Posted by jpc647

    If there is a key-way, how can it be in wrong, or not in the proper position. Doesn't the key way ensure the damper is can only go on one way?
  • Quote:

    Originally Posted by Fun71

    Yes, but it works only if there is actually a key in the key-way slot.
  • Quote:

    Originally Posted by jpc647

    I haven't pulled the damper off yet, but how can it be in the wrong orientation? Like on backwards or something?
  • Quote:

    Originally Posted by Fun71

    Like if there is no key in the slot then the only thing holding the dampener in place is the crank snout bolt. If there isn't a key, the dampener could have slipped on the crank to where it is now in the wrong position.
  
  February 26th:
• Quote:

  Originally Posted by Octania

  quite futzing around and VERIFY YOUR TIMING MARK by means of piston position.

I thought I must be going mad, but I looked, and, sure enough, this thread has been going on for eight months and absolutely no progress has been made.

This thread started on June 19th, and on June 20th, we began to advise the OP to confirm the TDC mark, and have repeated this advice over half a dozen times since then, not counting posts containing instructions on how to do it, and it's still not done.

At this rate, any one of us could have walked to his house, confirmed TDC, and walked home, and had time to stop several times for beer along the way.

Any chance this is some sort of a forum record?

JPC: We can't do anything more to help you until you confirm TDC.

- Eric

Fun71

Thanks for the synopsis with all the chaff removed.

jpc647

I did months ago. I showed that at TDC mark on the balancer is 3/4 off the timing tab. Did people miss this?

Thanks for this. But again, didn't I do this in the second picture from post #18 on page one? At TDC(plus or minue a degree or two using a screw driver or bolt) my timing mark is 3/4 of an inch above the upper limit on the timing tab. Isn't that what you asked me to do, and I did it?

MDchanic

Not at all, unfortunately.

The trouble is that this thread has gotten so long that none of us can remember exactly what happened when, so one could understand your thinking that, though.

We need you to use a stop-bolt or a dial indicator, or some other accurate way of determining TDC within about 1° to tell us where, exactly, TDC actually is.

If I recall, you used a screwdriver or something inserted in the hole to get a rough sense of where it was, but that can easily be off by 10-20°, because the piston moves so little at the very top of its travel.

Once you have an exact TDC point, you can mark it on the balancer and re-check your timing to see what it really is, and we can go on from there.

- Eric

jpc647

alright so I'm trying to reply to this for the second time, as the site timed out and I lost everything when I clicked post.

I bought a piston stop bolt and rotated the engine till it stopped, ever so gently. Then I rotated it back until it hit again. The middle point between the two was right about at 0*. Maybe like on 2* on the timing tab so thats close enough, I think. Now when I was rotating the engine over I could swear I could feel the bolt on the balancer move, but it could have been my imagination. Maybe the balancer itself was partially lose? I don't know.


This picture was supposed to show about where my base timing is. The timing tab last mark is at 12*. The balancer mark is almost 1.5 inches off the tab. The picture was sort of hard to get, and it's a little out or perspective, but it was for reference.

After I determined the balancer is now in the correct orientation, I started moving the dist. and listening. When I backed it down to about 18* base timing at idle, with vacuum advance removed and capped, the engine stumbled a bit. When I then rotated it back to where I started it stumbled again. So I tried to found a happy medium. It's right around 26 degrees base timing.

I drove the car, and it seems ehh. There doesn't seem to be any low end power. Or not as much as I was hoping for. The car seems to run okay, and it seems like after backing the timing down to 26* the car seems to really wake up in the higher rpms. Like before it shifts under WOT between 1st and 2nd the rear end gets very close to breaking loose. I've just never heard of this out of an 350 motor, shouldn't it have an easier time from a stop than going 25 and breaking the rear tires loose? Idle is now around 760-780. Before, the timing was about 37/38* at idle. So the balancer is correct, but the car still has a lot of timing. But with 18" of vacuum at idle, it's not like the car can have a high lift cam in it. So I'm back to the drawing board.

There's about 15/16 degree's of timing jump with the canister disconnected when I raise the throttle. With the vacuum advance connected, all in the timing is around 45/46*, just for reference.

Furthermore, the car seems to stumble from 0-5mph from a stop going WOT. I increased the accelerator pump shot, and it mitigated the problem a bit, but it seems slow to respond. I'm already using higher metering rods and the highest spings to get fuel faster. I just don't see how a "stock" small block Olds 350 needs more fuel than cfm. Or maybe I'm used to fuel injection where its instantaneous, and a carb needs a split second to react. I had originally bumped up the timing more, and it helped with that off-idle bog, so if the accel. pump can do that, and I bumped the timing down a little, I should be at a happy medium. Just don't understand why it's soo much timing...

Sampson

It would not be uncommon for you to have loosened the bolt when rotating the engine counter clockwise. Now that you have verified the balancer I would make sure the bolt is tight! Sometimes you have to look for the sweet spot since obviously it is not stock.
Set timing to highest vacuum on gauge..
Cut off engine and try to restart. If it is too advanced it will crank slow when hot. Back off distributor a little at a time until it starts normally. Test drive and listen for pinging. If it pings back off distributor until it does not ping. Check it with the light to see where you are.

jpc647

Thanks for the reply again. I can bump the timing all the way up to 38* initial timing and the engine still cranks fine. I was contemplating re-stabbing the distributor one gear off, so I could add even more timing, just to see how far I could go with it before it ping's or starts hard, but I haven't had the time for that yet. The car never turns over slowly, but sometimes after sitting for 30 minutes it has to crank a few times to start. That has more to do with the carb than anything else I think. If i hit the gas while cranking it'll fire almost immediately. But sometimes hitting the gas before cranking makes it worse. Maybe I'm too young to understand how starting a car with a carb is really done... haha

That's what I've been doing, trying to find that sweet spot. It's a give and take. A little more low end, vs a little more top end. I think for right now I may leave it around 28* initial. The motor may have been done around 97/98 with the rest of the car, I don't know what was available for Olds back then, but without taking the cam out and looking at it, all I can do it guess.

rjohnson442

for future reference you can get a pretty good estimate of timing with a length of tape cut out to a desired degree and a standard timing light. (size of banancer times 3.14 divided by 360) Then cut the piece of tape to the length of degrees you want and apply to balancer and hit with the light.
Example in this formula 28 degrees would be 1.46"
Or even better buy an actual balancer timing tape for 2 bucks and stick it on there!