The specs I looked up on line showed a 4 degrees btdc for initial timing and 28-32 dwell. I am running 93 octane gas. Should I be running a different timing to avoid detonation and knock? I just got the car at the end of last season and basically out for the first time this year. A buddy and I tuned the new date correct carb :thumbsup: and set the dwell and timing too. Want to make sure the timing is where it needs to be. Also just for clarification each timing mark is 1 or 2 degrees?

Car is running good and want to get it just right.:D

Thanks

dont mess with success lol. if you start messing around than you get it good. if it dont knock or ping you got it right. also when hot the starter dont drag.also if you got power real good you there.:beers:

Aw, come-on, mess with it! That's what it was made for! Here's what I did with mine, long before the warranty expired. (bought it new) Dwell 19*. Timing, 12* initial, 32* with the mechanical advance and 42* total at 2600 rpm. You'll also have to re-jet from 68's to 70's in the primaries. And don't forget to tighten up the valve lash .004 more than specs for 1969. You don't say what year you have but the 69 specs are loose for emissions reasons. Going tighter, back to the specs of previous years give more lift and duration and causes no harm. They are all the same components.
Oh, those specs I gave you were well known among the hotrod community and pro tuners of the day. I still run the same timing on my successor engine, an L88. But, you might have to run octane booster.;)

Sorry to leave the detail out of the post (though it is in my signature). The motor is a 68.

Wow 19* on the dwell? When we brought it down around 25 the motor seemed like it wanted to bog down because the idle started to come down.

I'd love to have to run octane booster :thumbsup: though we do have a Sunoco fairly close by that sells the 100 octane racing fuel for the Dirt Motor Sports cars. Last I looked it was $6.00/gal :sad:

Sorry to leave the detail out of the post (though it is in my signature). The motor is a 68.

Wow 19* on the dwell? When we brought it down around 25 the motor seemed like it wanted to bog down because the idle started to come down.

I'd love to have to run octane booster :thumbsup: though we do have a Sunoco fairly close by that sells the 100 octane racing fuel for the Dirt Motor Sports cars. Last I looked it was $6.00/gal :sad:
Oh,oh. I might have told you wrong about the dwell! Let me think:o . It's been 35 YEARS since I trashed my points.
Yeah, 19 thousands clearance with a feeler gauge, not 19 degrees. I'm trying to remember what that equaled in degrees but it's been 30 years since my dwell meter went to the dump! Again, sorry. :clonk:

The specs I looked up on line showed a 4 degrees btdc for initial timing and 28-32 dwell. I am running 93 octane gas. Should I be running a different timing to avoid detonation and knock? I just got the car at the end of last season and basically out for the first time this year. A buddy and I tuned the new date correct carb :thumbsup: and set the dwell and timing too. Want to make sure the timing is where it needs to be. Also just for clarification each timing mark is 1 or 2 degrees?

Car is running good and want to get it just right.:D

Thanks


4* BTDC is the factory spec for the car...most BB engines want about 36-38 degrees total...all in by 3,000rpm's. With an L78 engine you need to watch the fuel...they will run on pump gas, but they like something better. We have a number of original L78 cars 68-70, and mix our fuel 4/1 pump 93 and 108/112 race fuel...never any issues. This mixture will allow you to run some performance timing and avoid detonation. It also puts a little lead in the motor. Not all original L78 engines actually had a true 11 to 1 compression...there is a wide variation in chamber size in the factory rect. port heads...I would try to run 12-14* on the crank and 22* in the distributor for a total of 36*...

wilma