Timing

How much timing can you run safely in a 540 bbc 11.1 comp 18 degree heads at 25lbs boost? Thanks

 

What kind of ignition, that will make a difference.....?

Blessings.......Ron.

 

its a msd 7531

 

The 7531 can be run with a Pro Mag or a MSD ignition box.

Which do you have?

 

Advance

IDK I'v got a brand new combo similar to yours: 540 kb with 18 deg all solid under a Lf 14 hh at 28 over and 11.7 pistons. I gonna try 29 with a mag20. Less somebody tells me not to.

 

sorry its ingition box no mag just wasnt sure were to start at.

 

Start with 28 degrees and check the ground strap.

 

That's similar to my son's, but we have a ProMag 12 in it. It's happy at 34 degrees.

Blessings...........Ron.

 

34 degrees with a conventional big chamber and 32 with a smaller big chief style is what Oddy recommends for max timing. We ran 30 with a 14&18 degree chief and make over 2000hp at 40 psi. Never tried pushing it any further.
We've run MSD 12 and 44 with no noticable difference.
Mike

 

? cr.?

32 deg @ 40 psi
and what compression?

 

I run 28 deg with a 509 ci 18 deg big duke, so far so good. However after reading Mike Canters excellent piece on plug reading I think I need a little more timing to get some heat on the ground strap,maybe 30 deg will be better. However, alot of timing will make it hit the tires really hard. With the digital 7 you can retard the timing on launch to tame the hit.

 

We run 10.2-1 compression with 30 degrees and 40lbs of boost with a 14 deg Chief. I think it will make even more power with 32 degrees. Every fast Big Chief motor I know of has 30-32 degrees regardless of ignition or compression ratio.