Ok, I've been having spark knock problems since I bought the car.
At first I though it was largely due to having a non-cc quadrajet and a cc distributor.
I swapped to a non-cc distributor bought a crane adjustable vacuum advance and am using the blue/blue 800/3200 rpm spring setup.
Turned the vacuum advance about 11-12 turns in and am not using the limiter plate yet.
I still got audible spark knock at a base timing of 0 degrees running 87 octane gas.

My question is, how common is balancer ring slippage???
And how would I know if Its firing ATDC, and what would be the best method of timing without buying a new balancer right now.


Sorry for the long post....

If you need anymore info let me know.
Thanks in advance...

 

Also how should I go about adjusting the vacuum advance??

 

Dolph,

You can check the position of the timing mark on the outer ring against the crank keyway. You don't have to remove the balancer, but will have to remove the bolt to be able to see the crank keyway. You might be able to roughly judge teh position of the keyway, since one of the bolt holes for the crank sheave is aligned with the key, but measurement will be nearly impossible based on this position. The timing indicator in the outer ring should be retarded about 7° from this position with a stock timing tab on the TC cover.

 

Heres what happened to my balancer. Im still not exactly sure what caused it, but I think it was when I installed the balancer. I think when I was tapping it back with a hammer, the key came out of the crank a bit which caused a hairline crack in the balancer. Then I believe it was only a matter of time before the crack turned into this. For a week I thought I had a misfire, not a knock. If the balancer is turned, it feels almost exactly like a miss, at least on my engine. It may not be so noticeable on a 305/350 since they are internally balanced, and the balancer is not heavier on any side.

 

I don't think this would be your problem (even if the balancer slipped). Reason is that when a balancer slips, the actual reported timing as viewed from a timing light, will show advanced, normal correction is to retard the timing further to get the marks on target.

So if it has slipped, and you adjusted timing to say 10*BTDC, and the balancer has slipped say 10*, then you're really at "0", which is retarded, and generally doesn't cause a ping.


Usually you'll find guys with slipped balancers asking "why does my timing need to be at 30* BTDC (or some other high BTDC number) in order for my engine to idle?

 

you aren't planning on running your motor with that balancer are you? Spend $90 bucks and get a new one.

 

Sorry to question your integrity Ward....I thought that pic was Dolph88sc350TPI ........

 

after checking the mark like vader said, it looks to be right.

I run a little on the rich side, and dont' beleive there are any vacuum leaks.

I did remove most of the emmissions system, plugged most of the hoses coming off the carb (M4ME)

Could anything in the distributor cause the knock?
I swapped a known working cap on to see if that was bad, but could the rotor be bad somehow?
Also, I can hear spark in the distributor when its running. is that normal?

This is driving me CRAZY:lala:

 

Dolph,

You can HEAR the spark in the distributor? I'd say it's time for a new cap and rotor, test the wires and inspect them for damage, and look at the plug gaps. If the plugs need so much energy that you can hear the spark, you may have really wide gaps, failing plug wires, a distributor positioning problem (has the distributor been removed?), worn cap/rotor, or moiture or other contamination in the distributor. Usually, other engine noise masks anything from the distributor, even noise from a contact point set.

 

Vader,
I will probably buy a new cap & rotor in the next few days,
but the ones that are on it are fairly new(4 months old) just got some gp sorsen stuff.

I just changed the plugs (R45TS) with a .035 gap and double checked with a feeler gauge.

Fairly new bosch wires from the zone, but will check.

And the distributor has been removed recently, and just recently started getting bad knock.

Lately I've been doing ALOT to the engine and can't remember what or when I might have caused this.

The distributor is from an 81 c10, I've put a new pickup coil and module for a 79 camaro in, used the old condenser, put in a new crane adjustable vacuum advance, and the crane blue/blue springs, the weights that are on it have 41 stamped on them if that means anything.
Was going to put some new wieghts and center plate on but summit messed up my order and sent me some chrome valve cover hold downs instead of the recurve kit, the bag says HEI recurve kit but its just one side of hold downs.

 

Could slop in the valvetrain cause spark knock?
I hear some tapping on both heads.

 

It only knocks at startup and Part-WOT could I be leaning out?
I'm going to adjust the valves today and see what that does for me.

 

Dolph,

The reason I asked about the distributor being removed is that if it were installed one tooth off, the rotor may actually be between the appropriate contacts on the cap when the coil fires. This could account for some of the spark noise you are hearing, and possibly spark to the wrong cylinder at the wrong time.

 

Vader,
I have removed the distributor several times lately, but yesterday I double checked with the timing mark on TDC its pointing at #1 on the cap.
The engine runs smoothly from idle to 4500rpm.
It just knocks like crazy under heavy load, when I take it REAL easy on it, I atleast don't hear any audible knock.
I'm stumped, but thats not saying much.
Could anything on the carb need adjustment?