Harmonic balancer question

[Rustjunky67]

Is "True" TDC thirteen degrees away from the factory mark?

What does that indicate..... or maybe better stated: why do you ask?

 

[Schurkey]

What does that indicate..... or maybe better stated: why do you ask?

Mis-matched damper/timing pointer.

Many SBC engines--including yours--have the timing pointer "leaned-over" to the left side of the engine. Common as dirt. SOME SBC engines--NOT as common--have the timing pointer "straight up 'n' down", for example the 5.7L TBI in my '88 work-truck. I have to shine the timing light "straight down" through an access hole in the accessory bracket to see the timing mark/timing pointer.

The timing mark on the damper has to be positioned to match the timing pointer. The difference--if I'm remembering correctly--is 13 degrees. Even if I'm off a degree or five, the concept is the same--the mark on the damper has to be positioned to match the timing pointer.

Wild Guess: Your damper is completely usable...IF (big IF) it's used with the correct timing pointer, or if you re-mark it to be aligned with the pointer you have. I think you have a "straight up" damper being used with a "leaned-over" timing pointer.

Which could mean that this engine has been run with the timing 13 degrees retarded. You're gonna love the new-found power and fuel economy. (Or--am I wrong--it's been run 13 degrees advanced, and the knock-sensor has been saving your butt. I'm having trouble keeping advanced/retarded straight at the moment.)

 

[Rustjunky67]

Mis-matched damper/timing pointer.

Many SBC engines--including yours--have the timing pointer "leaned-over" to the left side of the engine. Common as dirt. SOME SBC engines--NOT as common--have the timing pointer "straight up 'n' down", for example the 5.7L TBI in my '88 work-truck. I have to shine the timing light "straight down" through an access hole in the accessory bracket to see the timing mark/timing pointer.

The timing mark on the damper has to be positioned to match the timing pointer. The difference--if I'm remembering correctly--is 13 degrees. Even if I'm off a degree or five, the concept is the same--the mark on the damper has to be positioned to match the timing pointer.

Wild Guess: Your damper is completely usable...IF (big IF) it's used with the correct timing pointer, or if you re-mark it to be aligned with the pointer you have. I think you have a "straight up" damper being used with a "leaned-over" timing pointer.

Which could mean that this engine has been run with the timing 13 degrees retarded. You're gonna love the new-found power and fuel economy. (Or--am I wrong--it's been run 13 degrees advanced, and the knock-sensor has been saving your butt. I'm having trouble keeping advanced/retarded straight at the moment.)

I'm pretty sure the cover is original to the truck as it is stamped "made in Canada" which is also where the truck was mfgd....
But as it is with this damper, the factory mark at tdc is to the right of the pointer (when facing truck), which would be advanced? I know next to nothing about timing.....
So getting my TRUE TDC mark at zero on cover would put that factory mark even further to the right (advanced?).....
I haven't looked yet but what happens if I line up true TDC to zero on cover and the mark on the sprocket isn't in the 12 o'clock position? How do you handle that if that is indeed the case?
I'm so damn flabbergasted with this whole situation that started out as just a simple power steering hose replacement lol

 

[Schurkey]

WHAT "sprocket"???

You marked "true" TDC based on your existing timing pointer...right? Paint a stripe on the damper to make "true" TDC obvious, put the engine together, and time the ignition based on your newly-configured true TDC mark. Forget the machined-in groove in the damper exists. Done.

 

[Rustjunky67]

WHAT "sprocket"???

You marked "true" TDC based on your existing timing pointer...right? Paint a stripe on the damper to make "true" TDC obvious, put the engine together, and time the ignition based on your newly-configured true TDC mark. Forget the machined-in groove in the damper exists. Done.

Sorry, GEAR

WHAT "sprocket"???

You marked "true" TDC based on your existing timing pointer...right? Paint a stripe on the damper to make "true" TDC obvious, put the engine together, and time the ignition based on your newly-configured true TDC mark. Forget the machined-in groove in the damper exists. Done.

Crank sprocket....
I get what you're saying about using my true tdc mark, I'm gonna go check shortly and see where the new damper I got lines up and also verify that when I'm at true tdc, the crank sprocket is still at 12 o'clock.... I'll report back

 

[Schurkey]

Ah. I didn't realize you still had the timing cover off. I figured it was reinstalled based on your photos.

You can compare the timing mark location in relation to the keyway machined into the ID of the damper.

 

[Rustjunky67]

Ah. I didn't realize you still had the timing cover off. I figured it was reinstalled based on your photos.

You can compare the timing mark location in relation to the keyway machined into the ID of the damper.

Yeah I had put it back on to check my balancer mark which sent me off to left field worried about that factory mark on damper not lining up...... I'm slowly but surely learning what and how and when to do things lol..... you CAN apparently teach an old dog new tricks (hopefully)

 

[Rustjunky67]

Ah. I didn't realize you still had the timing cover off. I figured it was reinstalled based on your photos.

You can compare the timing mark location in relation to the keyway machined into the ID of the damper.

Ok so here's what I have upon setting my true tdc mark at 0 on the pointer.....
if my calculations are correct, the crank sprocket is about 16 degrees from the 12 o'clock position (retarded? I'm not sure)
What to do in this situation?
It's like every bolt or nut or part I even look at raises another question or another issue‍‍
But i AM NOT gonna let it beat me by God

 

[PlayingWithTBI]

if my calculations are correct, the crank sprocket is about 16 degrees from the 12 o'clock position (retarded? I'm not sure)
What to do in this situation?

What I'd do is, put the timing chain back on, rotate the crank one turn so you can align the cam and crank dots. If you have to take the chain back off to align them, that's fine. Then install the timing cover without turning the crank. Take a paint stick or some way of marking metal. Paint a line on the cover pointing at the line on the balancer or, a line on the balancer in line with zero degrees on the pointer. Rotated the crank 1 turn until it points at zero again, and stab the dizzy pointing at #1 cylinder

 

[Rustjunky67]

What I'd do is, put the timing chain back on, rotate the crank one turn so you can align the cam and crank dots. If you have to take the chain back off to align them, that's fine. Then install the timing cover without turning the crank. Take a paint stick or some way of marking metal. Paint a line on the cover pointing at the line on the balancer or, a line on the balancer in line with zero degrees on the pointer. Rotated the crank 1 turn until it points at zero again, and stab the dizzy pointing at #1 cylinder

I have rods and lifters out and FINALLY about to pull this cam out and do a good inspection of it.... so i can move cam sprocket freely....I was just going through finding true tdc and etc just to learn while still in the teardown phase so when I put things back I'll actually understand somewhat what I'm doing..... thanks for the advice.....