68 timing spec 4 degrees? And recuring distributor
Thread Starter
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
68 timing spec 4 degrees? And recuring distributor
I noticed my 68 Small block has a factory spec of 4 degrees btc. Is that for emmision purposes?
Anyway, so I buy a set of springs to recurve it to get faster advance. Set it at 36 total at about 3000rpm. But now my initial is 0 degrees! And the car runs terrible off the line, duh. The distibutor is set up for 36 degrees centrifugal advance.
So, will changing weights change the total amount of centrifugal advance? I would like to have about 10 initial, 36 total. How do I set it up for about 26 degrees?
Gary
Anyway, so I buy a set of springs to recurve it to get faster advance. Set it at 36 total at about 3000rpm. But now my initial is 0 degrees! And the car runs terrible off the line, duh. The distibutor is set up for 36 degrees centrifugal advance.
So, will changing weights change the total amount of centrifugal advance? I would like to have about 10 initial, 36 total. How do I set it up for about 26 degrees?
Gary
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Are you using vacuum advance? If so, make sure it's connected to a manifold (not ported) vacuum source. This should give you the advance you need at idle.
Still, I gotta admit that 36 degrees of mechanical advance seems like a lot. (Paging Lars . . . !)
Still, I gotta admit that 36 degrees of mechanical advance seems like a lot. (Paging Lars . . . !)
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
If you have 36 degrees of centrifugal advance, you have a defective distributor. Don't try patching the problem by installing some aftermarket weights. You need to pull the distrubutor and repair that advance curve.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
My dist was bad and gave me about 35 degrees centrifical advance. I took it to a shop that has an old dist. machine. They fixed up my dist so I now have 14 initial and 36 total. They had to braze in some material so it would not advance to much. Been running perfect for the last 5 years now. 
Thread Starter
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
I was just wondering if that was some bizarre one year only (68, start of air pumps and emmisions) emissions design. 4 initial seemed very low. Thought maybe initial was low to decrease NO levels and they built the distributor with more advance to get up to normal levels.
Gary
Gary
