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Discussion Starter #1
I know there are two different kinds of harmonic balancers for the SBC (not counting sizes). One is keyed to put the TDC mark at the top and one is keyed to put the TDC mark down the driver's side about 10-20 degrees.

When I built my 305 I used a balancer that is keyed to put the TDC mark down the side. I verified this when I degreed the cam and found TDC.

Now, the engine is in the cruck and running. However, in order to make it idle the best, I had to rotate the distributor until the timing mark on the balancer is at the top. This is with the vacuum advance disconnected and plugged.

Why is my timing mark off that way?

Jack
 

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timing issue

Which post on the dizzy is the spark plug wire for number 1 spark plug?
 

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#1 is #1 no matter what post it is on. You can use any of the 8 as long as it is wired correctly and not effect the timing.
 

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#1 is #1 no matter what post it is on. You can use any of the 8 as long as it is wired correctly and not effect the timing.

You can???????????????:poke:

Next you'll tell me the piston needs to be TDC on the compression stroke before you can put the timing chain on. (Seriously, I had an argument with a guy one time about that. The piston dont care if the cam aint hooked up. DUH):poke: Just messin with ya Neil

Anyway back to the topic, if its running good the way you have it, has good power without pinging at WOT I would call it good.
 

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is the dist . functioning correctly ? they actually make 3 different ballancers the 2 early ones and the one that you have to time behind the water pump.try timing it off of # 6 it is the companion cylender. you said you verified tdc when degreeing the cam did you mark the ballancer and the covers timing tab?
 

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thats whats good about using the manifold vacuum to the vacuum advance.. better idle,, cooler idle..
if you try to do it all with initial timing?? it will probly kick back on the starter and break the starter nose..:texas:
 

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the only problem with manifold vacuum at idle is as soon as you hit the throttle your avdance drops off just when you want it to pick up.that is the reason gm got away from it in the early 60 s
 

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Discussion Starter #9
#1 is #1 no matter what post it is on. You can use any of the 8 as long as it is wired correctly and not effect the timing.
True. As long as you rotate the distributor to fire #1 at the proper time.
 

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Discussion Starter #10
Anyway back to the topic, if its running good the way you have it, has good power without pinging at WOT I would call it good.
But why is the mark on the balancer so far off? Am I running that much initial timing?

Oh, I forgot to mention that it idles at about 1000 RPM.

Jack
 

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Discussion Starter #11
is the dist . functioning correctly ? you said you verified tdc when degreeing the cam did you mark the ballancer and the covers timing tab?
I assume the dist is OK. How would I know?

Yes, I installed a Mr Gasket timing tab and lined it up.

I just stopped the engine with the mark at the top of the balancer on the #1 firing position of the distributor rotor. The valves for #1 were both not fully closed. I then rotated the engine to MY timing mark and both vlaves were closed.

It sure looks like I'm running about 22 degrees of initial timing.
 

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But why is the mark on the balancer so far off? Am I running that much initial timing?

Oh, I forgot to mention that it idles at about 1000 RPM.

Jack
When you built the motor and you had #1 piston at TDC. Did you bolt a timing tab to the timing chain cover and set it up so the line on your balancer was pointing at zero on the timing tab?

On those timing tabs each mark is usually two degrees. If you did and now its way off, then yes, something is wrong or something has moved, but unless that was done correctly who knows if its off now.

You could always remove #1 spark plug and stick a long screw driver into the cylinder and rotate the engine until #1 piston is at TDC on the compression stroke and then you'll know if your timing tab and balancer mark are set correctly.
 

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I assume the dist is OK. How would I know?

Yes, I installed a Mr Gasket timing tab and lined it up.

I just stopped the engine with the mark at the top of the balancer on the #1 firing position of the distributor rotor. The valves for #1 were both not fully closed. I then rotated the engine to MY timing mark and both vlaves were closed.

It sure looks like I'm running about 22 degrees of initial timing.
When you have #1 piston at TDC, pull off the dist cap and make sure the rotor is pointing to the post that #1 spark plug wire is attached to.
 

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Discussion Starter #14
When you built the motor and you had #1 piston at TDC. Did you bolt a timing tab to the timing chain cover and set it up so the line on your balancer was pointing at zero on the timing tab?

On those timing tabs each mark is usually two degrees. If you did and now its way off, then yes, something is wrong or something has moved, but unless that was done correctly who knows if its off now.

You could always remove #1 spark plug and stick a long screw driver into the cylinder and rotate the engine until #1 piston is at TDC on the compression stroke and then you'll know if your timing tab and balancer mark are set correctly.
When I degreed the cam I used a piece of coat hanger wire as a pointer. I used a dial indicator on the piston in the #1 cylinder. I rotated the engine until the dial indicator read max lift and set the pointer to zero on the degree wheel.

After everything was put together I used a piston stop and rotated the engine until it hit the stop. Wrote down the degrees and rotated it the other way until it hit the stop. Wrote down the degrees and figured out the mid point. Removed the stop, rotated the engine to the mid point, and set the Mr Gasket timing tab to zero.

The car is going to the paint shop today, so I won't work on it again until it comes back.
 

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When I degreed the cam I used a piece of coat hanger wire as a pointer. I used a dial indicator on the piston in the #1 cylinder. I rotated the engine until the dial indicator read max lift and set the pointer to zero on the degree wheel.

After everything was put together I used a piston stop and rotated the engine until it hit the stop. Wrote down the degrees and rotated it the other way until it hit the stop. Wrote down the degrees and figured out the mid point. Removed the stop, rotated the engine to the mid point, and set the Mr Gasket timing tab to zero.

The car is going to the paint shop today, so I won't work on it again until it comes back.
I've never used that method before, but I'm sure it works fine. I've always set the timing tab before the heads are on so I know #1 is at TDC.

Anyway, at this point to be sure everything is where it needs to be, I would put #1 at TDC (on compression) and see where your timing marks are and where the distributor is set to. Then you'll know everything is where it should be. Its a pain in the butt, but at least you wont be guessing you'll know for sure.
 

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Discussion Starter #18
This morning I started out to the paint shop, but it was running like crap and I didn't think I could make it. I turned around and went back home. That was a total of about 2 miles.

At home I backed the timing off several degrees and sped up the idle. Then drove it down the block. As soon as I gave it any gas it started bucking, so I idled it back home. Then I called the paint shop and rescheduled for next Friday.

I guess I'm going to have to verify TDC for sure. If it's correct, I have no idea what to do next.
 

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This morning I started out to the paint shop, but it was running like crap and I didn't think I could make it. I turned around and went back home. That was a total of about 2 miles.

At home I backed the timing off several degrees and sped up the idle. Then drove it down the block. As soon as I gave it any gas it started bucking, so I idled it back home. Then I called the paint shop and rescheduled for next Friday.

I guess I'm going to have to verify TDC for sure. If it's correct, I have no idea what to do next.
Well that sucks. Just start with the basics. You know what to do. TDC #1, check the balancer mark in relation to your timing tab, make sure its zero and then verify the dist is pointed at #1 spark plug wire.

If its correct, set the timing at 36 total if you can. What kind of ignition system do you have?
 

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Discussion Starter #20
Well that sucks. Just start with the basics. You know what to do. TDC #1, check the balancer mark in relation to your timing tab, make sure its zero and then verify the dist is pointed at #1 spark plug wire.

If its correct, set the timing at 36 total if you can. What kind of ignition system do you have?
I have an HEI distributor with built-in coil. The cap is the new Accel #8141R that rearranges the plug wires so they're inline 1-3-5-7 and 2-4-6-8. No crossed over wires.

The distributor is from Skip White. It's a 65 KV he says.
 
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