Timing woes

[84K30]

My truck, a 1984 K30 with a 454 and 4 speed manual, runs fine. The plugs I just changed we’re all a very light tan color. However, since I can never leave well enough alone, I decided to check and adjust (if necessary) the baseline and total timing. A member, Craig85 I believe is his screen name, provided me with 4 degrees BTDC as the factory idle timing setting. After letting my engine warm up, I noticed that the idle timing was indicated as well in excess of 18 degrees BTDC, the maximum ranges on my pointer. As I advanced the timing towards the 4 degree mark, the engine began to run rough and nearly died. Timing was indicated as still in excess of the 18 degrees At this point. I immediately began to question if the balancer was (re)installed irrespective of the pointers location or if the pointer was (re)installed on the wrong side of the engine. My pointer is on the drivers side at approximately the 1-2 o’clock position, is that correct?

If so, are balancers “keyed” or “notched” in a way that it would only go on one way?

In the mean time, I just set the base timing where it sounded healthiest and readjusted the idle speed to 700 and it still runs just fine.

Does anyone know what the total timing should be for my year and engine/trans configuration? I’ve seen A range of 32-38 degrees between a range of 2500 to 3500rpm.

Thanks,
Eric

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[Bextreme04]

Did you have it warmed all the way up and the vacuum advance line disconnected and plugged? Are you sure the timing light trigger was on the #1 cylinder?

 

[legopnuematic]

Did you unhook and block the vacuum advance off when you set base timing? that would likely explain your high initial timing. In my 76 I have my base timing set at 16 degrees advance.

 

[84K30]

Vacuum line was left connected to the distributer but plugged. I did not plug the port on the carb though. I am 100% sure the timing light was on the plug wire for the #1 cylinder. Was at ~210 degrees where it normally operates.

I’ve attached a photo of the timing indicator (covers balancer to the point that I couldn’t even read it if it were within range) and port on the front passenger side of the carburetor that I didn’t plug after disconnecting the dizzy vacuum line and plugging it.

-Eric

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You must be registered for see images attach

 

[Bextreme04]

haha... You have to block the vacuum source. Blocking the hose running to the distributor does nothing but add a vacuum leak, because the carb port is the spot trying to pull vacuum. You need to either disconnect from the distributor and block the hose there, or put a cap on the carb port when you unplug the hose from there.

I would recommend you rotate the crank until you can see the mark and then extend the mark out to the pulley so you can accurately read it. I would use a small line of whiteout if I was doing it.

That damper might not be the right one... or the mark might be on the pulley and it was not installed properly at some point so the mark on the pulley no longer lines up with the mark on the damper. The only sure way to know is to use a TDC stop tool and mechanically verify the timing marks. You would basically screw the tool into the #1 spark plug hole and manually rotate the engine clockwise until it makes contact with the stop. Make a mark on the damper where the timing mark points to 0. Then rotate the engine all the way counterclockwise until it contacts the stop again. Make a mark on the damper where the timing mark points to 0. Now the actual TDC timing mark should be exactly halfway between the two marks on the damper.

 

[Snoots]

Who the heck are you anyway? Who runs Autolite plugs (or furd parts) on their GM truck anyway?

I mean, DAMN!

 

[78C10BigTen]

Who the heck are you anyway? Who runs Autolite plugs (or furd parts) on their GM truck anyway?

I mean, DAMN!

Ive got E3s lol

 

[84K30]

Damn that’s embarrassing! I’m no mechanic but I should have known that. Will do what you recommended and report back.

The autolites are the old plugs I took out. Don’t worry, I put ACDelco plugs in when I changed them.

 

[Rusty Nail]

yea me too.

wtf is with them autolites yo? your truck aint gonna like that..

hahaha! lookit this one - party33



ready for the new report -with pictures this time ok?

 

[Ricko1966]

haha... You have to block the vacuum source. Blocking the hose running to the distributor does nothing but add a vacuum leak, because the carb port is the spot trying to pull vacuum. You need to either disconnect from the distributor and block the hose there, or put a cap on the carb port when you unplug the hose from there.

I would recommend you rotate the crank until you can see the mark and then extend the mark out to the pulley so you can accurately read it. I would use a small line of whiteout if I was doing it.

That damper might not be the right one... or the mark might be on the pulley and it was not installed properly at some point so the mark on the pulley no longer lines up with the mark on the damper. The only sure way to know is to use a TDC stop tool and mechanically verify the timing marks. You would basically screw the tool into the #1 spark plug hole and manually rotate the engine clockwise until it makes contact with the stop. Make a mark on the damper where the timing mark points to 0. Then rotate the engine all the way counterclockwise until it contacts the stop again. Make a mark on the damper where the timing mark points to 0. Now the actual TDC timing mark should be exactly halfway between the two marks on the damper.

2 other ways I've done the same thing stick a drinking straw in the plug hole and put your finger on it have a friend rotate the engine you will feel the piston park and stop moving .Ive also stuck a nonfouler in the plug hole as a guide for a piece of heavy wire put the dial indicator on the wire rotate the engine until I see the indicator quit moving.Accurate enough for most instances you need to find tdc.

 

[84K30]

Update: after bringing my truck up to temp, 210, I disconnected the vacuum hose from the distributor and plugged it. The TDC line on the balancer is around the 10 o'clock position when the #1 spark plug fires. So someone either installed the balancer without regard to TDC or removed it and reinstalled it without marking it. I ordered a TDC/piston stop tool so I can mark the balancer correctly and adjust my idle and total timing as needed. I'll provide an update when that time comes.

 

[Rusty Nail]

Yeah?
How IS the quality of said balancer?
They can separate...did you see any splits or cracks in the rubber?

NEEDS MOAR PIX
This thread.

 

[84K30]

Update:

I bought a “piston stop tool” from Summit. It does not work as advertised. I can turn the crank full rotations without meeting resistance that I cannot overcome without slight effort. I noticed in all of the demo videos for the “piston stop tools” that the engines are on a stand, have the spark plugs and crank pulley removed, don’t have belts, hoses, exhaust manifolds or anything else obstructing their view of the piston. Oh and TDC is already identified beforehand.

This is my first big block Chevy & it seems like the plugs are damn near horizontal when installed vs a 45 degree angle on small blocks. This is probably why the tool didn’t work.

Anyways, I just put everything back to the way it was. The components are new and it runs great, has decent oil pressure and doesn’t overheat so I’m just going to drive it. I’ll be sure it is correct when this engine needs rebuilt or replaced with something else.

Thanks to all of you who helped!
-Eric

 

[QBuff02]

It looks to me by the picture that you posted that the balancer has slipped. If that's the case you'll never get it timed by using it. Unless there's a parts mismatch the timing pointer should not protrude beyond the front of the balancer ring. the fact that it's well in front of tells me the balancer has been walking apart. The inner part of the balancer is keyed to the crankshaft so it won't move but the outer ring of the balancer is known to walk back and forth as well as slip in relation to it's original location as they fail over time. So for a quick and dirty method since you were having trouble locating tdc (kind of quick and dirty) remove the balancer bolt and locate the keyway on the crankshaft snout and bring it around until it's pointing up at the center of the #1 cylinder and that is top dead center. The keyway for the balancer is indexed into the crankshaft so as it's pointing at tdc when the engine is on tdc on #1. Then verify your TDC mark on the balancer and I bet you'll see it's off by a wide margin. In the meantime, sometimes the best timing that can be done is by sound and feel. If it sounds good and feels good, run it. lol

 

[bucket]

It looks to me by the picture that you posted that the balancer has slipped. If that's the case you'll never get it timed by using it. Unless there's a parts mismatch the timing pointer should not protrude beyond the front of the balancer ring. the fact that it's well in front of tells me the balancer has been walking apart. The inner part of the balancer is keyed to the crankshaft so it won't move but the outer ring of the balancer is known to walk back and forth as well as slip in relation to it's original location as they fail over time. So for a quick and dirty method since you were having trouble locating tdc (kind of quick and dirty) remove the balancer bolt and locate the keyway on the crankshaft snout and bring it around until it's pointing up at the center of the #1 cylinder and that is top dead center. The keyway for the balancer is indexed into the crankshaft so as it's pointing at tdc when the engine is on tdc on #1. Then verify your TDC mark on the balancer and I bet you'll see it's off by a wide margin. In the meantime, sometimes the best timing that can be done is by sound and feel. If it sounds good and feels good, run it. lol

I concur, that picture shows an outer ring that has slipped out of place on the hub. Time for a new balancer before that one comes completely loose and starts eating the timing cover.