283 timing indicators

[57150n]

I have have a 1957 Chevy with a 1961 283. Some one rebuilt the engine before I bought it. There are 2 timing indicator markers and I think 1 of them should be taken off or ignored. The attached picture (if I got that to work) shows the indicators and where it is presently timed, it looks to me to be too far advanced. Your help will be appreciated. 57 150

9230

[chevynut]

I would pull #1 spark plug and find TDC to confirm which one is right, if any. IMO that's the only way to be sure. Seems weird to have two of them.

[chasracer]

There's a few things that could be going on here. Is there one timing tab that is bolted on and one welded to the timing chain cover? I honestly can't remember when Chevy started welding the tabs on and I'm thinking that someone substituted a later cover plus bolted on the original one. Another thing to remember is that old balancers of that age are prone to ring slippage. The rubber will deteriorate and the outer ring will slip - the timing can look advanced when in truth it's not. You'll need to get back to basics with TDC and choosing which tab to use along with verifying that the balancer is still in good shape.

[scorpion1110]

ChevyNut is correct. You need to determine TDC. Some use a Piston stop in the spark plug hole. I typically remove plug, place finger over hole, have friend bump starter until I feel compression. When I feel compression I bring it around by hand. I use a plastic straw to see when the piston comes to the top of the bore. Insert the straw and when the piston presses it and it doesn't move, then you should have TDC or be darn close.

At that point check the tabs, you should really be at zero somewhere. At this point you will know where you are. Use a white paint pen to get a mark, and remember you care about not only mark on the timing tab you care about the mark on the balancer. The 66 283 I rebuilt last year had a timing cover with welded tab. To Chas' point above, if you need a new 283 balancer you can get them reasonably from Jegs; I have a brand new one in the box that I didn't use that I got from Jegs.

One point. If you do have to replace a 283 balancer, I believe you cannot use an installation tool unless the crank snout was drilled. I always drill my cranks for easy installation of the balancer with an install tool and I always use a crank bolt. If your crank is not drilled, I believe you literally have to bang the balancer on with a mallet. I think a dead blow with a wood block. My 66 283 had an undrilled cast crank.

Scorp

[Rick_L]

One of those TDC marks is wrong. All 283s used a balancer that had the TDC mark on it lined up with the keyway. 69-up engines had the TDC mark 10° CCW from the keyway. But there is not 10° between those two marks - so one just isn't right.

The tabs were welded up until the late 60s, about the time 283s were phased out. You can buy a bolt on tab for the balancers with TDC marks that are lined up and also with the 10° offset, or at least you once could.