Timing unrealistically out of range

[Surfdude]

The local Pep Boys and AZ had did not know what timing tape was even when I showed them pictures on my phone.  So I would need to order some, that is the primary reason I am holding off doing that as the first solution.  I have until the 11th of June, then I get to pay full price again for a retest.  Gotta love this state and it ability to raise revenue.  I have a brother in law who lives in Vegas, I may just register the vehicle in Nevada and be done with it.

I had initial thoughts of doing a LS swap but I have to be careful, I would need to pass the emissions of the year of the engine.  So, a 2005-ish engine means I would have to meet all of the ODB II requirements.  Not really feasible for a truck that is being used to haul surfboards and bikes around.  I even put the vinyl floor in it so I can get the sand out easier. 

I will let keep this up until it is resolved one way or another.

[rich weyand]

Basic starting point: The engine won't lie to you.  The timing wheel might, the timing tab might, but the engine won't.

So if that's where it runs good, and you're not getting any knocking, you are between 4 and 20 degrees BTDC.

Period.

OK, so back to basics.  Line up the timing mark at 0 BTDC as in the pics, and use an inspection mirror to see where the keyway is on the crankshaft.  It should be at 45* as seen from the front -- between 1 and 2 on the clock.  That can't lie either.  If it is straight up, or straight out at 3 o'clock, then your timing wheel/tab combination is 45 degrees off.  I suspect you will find the keyway is at 3 o'clock or more when the mark is lined up.

[Surfdude]

Rich,
I know the answer to this one.  The keyway is at the 12 o'clock position when the timing mark is at 0 on the tab

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[roundhouse]

Order a tape from summit or jegs



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[Rattler12]

third picture looks like you're closer to firing 8 than 1 but if you have the #1 plug wire in that cap position and followed through with the 8,4,3,6,5,7,2 in succession that shouldn't make a difference in what a timing light would show at the crank. 

[rich weyand]

Rich,
I know the answer to this one.  The keyway is at the 12 o'clock position when the timing mark is at 0 on the tab

So there you go.  Wrong timing wheel or wrong tab.  The #1 cylinder is at TDC when the keyway is at 45* CW from straight up when viewed from the front.  (The keyway lines up with the #1 rod throw.)  That is true of all GM V8s ever.

So the timing mark is off 45*.

But then it should look like you are running 40 or so degrees AFTER TDC, because the timing mark is going to have to move another 45* past the tab before you hit the actual TDC.

[rich weyand]

Let me ask you.  Is your current timing tab at 12:00 on the balancer wheel?   That is, is it on top of the engine in the front?  Sounds like the balancer wheel is one for the side mounted timing tab, which is more like 1:30 on the balancer wheel, while your tab is on the top, so they aren't for the same setup.

So how did you get here?  Lessee.  The original timing wheel was set up for the top-mounted tab, so you set it there and it runs fine.  Then the balancer slips because the rubber is old and hardened.  So you know this could be the issue, so you replace the balancer with the much more common one that needs the side tab, and now you can't get the thing to time properly with the new balancer on the old tab.

Solution:  Move the tab, or get the rarer balancer for the 12:00 tab.

[rich weyand]

Note notation on this one: "w/Center Timing Mark".

http://www.jegs.com/i/Proform/778/66509/10002/-1

Note this one doesn't mention the timing mark, so it will be in the earlier 2:00 position.

http://www.jegs.com/i/Proform/778/66510/10002/-1

I would move/replace the tab.

[rich weyand]

Went back and looked at pic #2.  Looks like that is the 2:00 position, same as mine.  I could reproduce this picture.

Hmm.  Timing mark is still wrong, though.  Needs keyway at 45*.

I used this widget over the balancer to keep from relying on the balancer for the timing mark.

http://www.jegs.com/i/Proform/778/66518BKC/10002/-1

[VileZambonie]

Do you have a timing light and have you verified their readings?

I have a basic timing light not one with regressive timing abilities.  I can say that the timing mark is not  currently visible at the tab.

I see that the distributor is at 6 o'clock position when currently at TDC. I can move the gearing so it is at the 5 position where # 1 is located to see if that helps although I don't see how it could jump teeth during normal driving.

If it fixes the immediate problem I can come back to the why, I suppose.


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It's irrelevant. Either your balancer is incorrect or your timing tab is incorrect or you are putting the inductive pickup on the wrong wire.

[Engineer]

I am a bit confused. I went back and reread the OP. How were you able to set the initial timing at 8° BTDC if the balancer was incorrect for the timing tab?

[rich weyand]

I think the original balancer slipped after it was set, then he installed a new balancer, but I think it is the wrong one.  So now he can't set the timing from that new mark.  He's 45* off (crankshaft keyway at 12:00 with timing mark on 0).

[Surfdude]

I think the original balancer slipped after it was set, then he installed a new balancer, but I think it is the wrong one.  So now he can't set the timing from that new mark.  He's 45* off (crankshaft keyway at 12:00 with timing mark on 0).

The end of the saga;. The short version is that I used a bit of HS geometry and re-marked the balancer 45 degrees earlier with engine tuned for max vacuum and no knock.  The new mark hit 8 degrees with the light.  I passed smog today so time to move on. Thank you for the help. 

On a side note, I was able to pick up a fender with inner and a new tailgate with CHEVROLET stamped for great price this weekend.  Poor guy had dropped a 6 liter and 4160 in his 77 stepside and had just got out of the body shop the day before when he was T-ed in the driver side fender.  Truck all blocked and primered. Frame bent but no one hurt. His rust free cab may be available. 

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[rich weyand]

The end of the saga;. The short version is that I used a bit of HS geometry and re-marked the balancer 45 degrees earlier with engine tuned for max vacuum and no knock.  The new mark hit 8 degrees with the light.  I passed smog today so time to move on. Thank you for the help. 

There ya go!  Thanks for letting us know.