Timing is way advanced

JACK34 · May 12, 2023

I recently purchased a 1973 K10 with a rebuilt 350 in it. I have no idea what was done to it internally, it has a 1406 Edelbrock carb on it and it runs amazing but I have not driven it yet so only gauging that in the driveway, start up ETC... I'm waiting on one tire then I will take it out on the road tomorrow. I changed the plugs the old ones looked great and yesterday I got around to checking the timing. I already marked the notch in the balancer with white paint. I unhooked the vacuum line to the advance after it was warmed up shot my timing light down on it and nothing. Well after moving the light around I found the mark and it was way advanced, not even close to the timing tab. I was going to adjust it but couldn't find my distributer wrench. But, the engine runs amazing and I can tell even from not driving it yet it's got a lot of torque. Why would someone have it that advanced? If I did not have a timing light and only my ears and the way the engine acts I would have locked it down right where it is. Any thoughts would be appreciated. Thank you.

Ricko1966 · May 12, 2023

Maybe it's not that advanced. Balancer slipped wrong timing tab,no vacuum advance. Make sure you have a working vacuum advance. For now I wouldn't try timing it. Wait till it's drivable then we will work on the mystery

fast 99 · May 12, 2023

or centrifugal advance could be stuck.

Rickf · May 12, 2023

You might pull the #1 plug to find if the TDC mark has moved .

Matt69olds · May 12, 2023

I’m not very familiar with all the different “families” of small block Chevy, didn’t some years have the timing marks in different locations? Maybe he has a balancer/timing mark mismatch?

It’s easy enough to make a new timing mark on the balancer. Put some masking tape around the balancer, put a piston stop in the number one cylinder. Disable the ignition, slowly rotate the engine BY HAND until the number one piston hits the piston stop. Make a mark on your masking tape lining up with the zero mark. Rotate the engine BY HAND(!!) the other direction until it stops again, make another mark. TDC will be exactly between those marks.

fast 99 · May 12, 2023

Yes there were 2 timing tab locations that I know of. One was behind the water pump at almost 12 o clock. Other one was on the drivers side at about 2 o clock.

Ricko1966 · May 12, 2023

Again don't mess with things tell its drivable. I changed this,I did that and it runs terrible. Did it run good before you did this and that? IDK I never drove it. Find out what your baseline is before you mess with things.

JACK34 · May 12, 2023

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JACK34 · May 12, 2023

Thats what happened to me. I was just looking at the balancer and saw the notch and then down a little further was a scroll mark. I marked that and it's spot on. Someone at some point did what this guy did. Good info in the video. Thanks everybody.

Ricko1966 · May 12, 2023

Matt69olds said:
I’m not very familiar with all the different “families” of small block Chevy, didn’t some years have the timing marks in different locations? Maybe he has a balancer/timing mark mismatch?

It’s easy enough to make a new timing mark on the balancer. Put some masking tape around the balancer, put a piston stop in the number one cylinder. Disable the ignition, slowly rotate the engine BY HAND until the number one piston hits the piston stop. Make a mark on your masking tape lining up with the zero mark. Rotate the engine BY HAND(!!) the other direction until it stops again, make another mark. TDC will be exactly between those marks.

I am so glad you wrote this up this way. Too many times I've seen guys leave out the fact that you have to stop the piston in each direction,not just bring it up to the stop.

Buck69 · May 13, 2023

Ricko1966 said:
I am so glad you wrote this up this way. Too many times I've seen guys leave out the fact that you have to stop the piston in each direction,not just bring it up to the stop.

Some diesels don't have a hole to pin or a reference mark. Instead of a stop you use a dial indicator but go through the injector hole. Split the before and after.

Ricko1966 · May 13, 2023

Buck69 said:
Some diesels don't have a hole to pin or a reference mark. Instead of a stop you use a dial indicator but go through the injector hole.

Yep done that,that's how you time 2 strokes also. Should say how you used to time 2 strokes IDK how it's done now. Used to use a dial indicator and check when the points break in mm before tdc.

Trucksareforwork · May 13, 2023

JACK34 said:
I recently purchased a 1973 K10 with a rebuilt 350 in it. I have no idea what was done to it internally, it has a 1406 Edelbrock carb on it and it runs amazing but I have not driven it yet so only gauging that in the driveway, start up ETC... I'm waiting on one tire then I will take it out on the road tomorrow. I changed the plugs the old ones looked great and yesterday I got around to checking the timing. I already marked the notch in the balancer with white paint. I unhooked the vacuum line to the advance after it was warmed up shot my timing light down on it and nothing. Well after moving the light around I found the mark and it was way advanced, not even close to the timing tab. I was going to adjust it but couldn't find my distributer wrench. But, the engine runs amazing and I can tell even from not driving it yet it's got a lot of torque. Why would someone have it that advanced? If I did not have a timing light and only my ears and the way the engine acts I would have locked it down right where it is. Any thoughts would be appreciated. Thank you.

Hard to really tell from the definition of “way advanced” because most of the old school timing tabs only went to, what? 14 btdc?

A few things that might be in play:

- big cams like a lot of timing, so 18+ btdc initial (base) timing isn’t out of the ordinary.

- some people lock out their mechanical and vac advances and just run straight timing at 38 or so btdc. Common in race car type builds. Common with big cams.

Does your vac advance actually work? Can you tell if it is advancing timing? If not, I bet you have a locked out distributor. Pull the rotor and look for welds.

JACK34 · May 13, 2023

Thank you everyone please read my post above and check out that video. I figured it out the video explains it all. Thank you. I found the other mark someone else put on the balancer after watching the video. It was just faint and I overlooked it. Hope this may help someone else with the same issue.

peats · May 15, 2023

I would just drive it and keep advancing it 2 degrees at a time untill it detonates and then back off 2 or 4 degrees . who knows what balancer or timing mark is on it. If it runs good now don't get too far away.

Timing is way advanced

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