Locked out timing on circle track sbc

[rdkonkel]

Bmod motor , 9.5:1 dart iron heads with 76 cc combustion chamber and 165 intake runner.
Flat tops, edelbrock alum intake ,
1-3/4" headers, 92 octane premium pump gas with 10% ethanol
Was looking for anyone with dyno results for best locked out timing to be used on a motor equivalent to this.
Have been running 35, but the crate websites are using lower timing numbers like 32 if I remember.

[JDR Performance]

The 602 has Vortec heads, so it'll be different than yours.

[Frankshaft]

That combo may very likely want even more timing, not less. All you can do is try say 32, see how it runs, then 37 see how it runs etc. 76cc chamber flat tops, it literaly could want 40. You never really know till you try it. ANd those crates have better chambers than what you have. Vortecs aren't they? Those can want as little 30 sometimes, and are much more efficient than what you have.

[dirtracr5]

Bmod motor , 9.5:1 dart iron heads with 76 cc combustion chamber and 165 intake runner.
Flat tops, edelbrock alum intake ,
1-3/4" headers, 92 octane premium pump gas with 10% ethanol
Was looking for anyone with dyno results for best locked out timing to be used on a motor equivalent to this.
Have been running 35, but the crate websites are using lower timing numbers like 32 if I remember.

Those heads will want 36 degrees. Those headers are to big also and not helping you.

[racear2865]

are u a true 9.5 motor with zero deck height and what head gasket .020/.039. Borrow a set of step headers and try and smaller per above
reed

[F-BIRD'88]

While a quick dyno pull test may show best power at 36deg BTDC,

On the track when running hard continuously the motor may well not quite need 36deg..Like 32-34deg for best continuous power.

The motor becomes a little bit more heat efficient once the combustion chamber piston and valves get good and hot
so combustion is a slight bit faster when continuous hard running.
So, the engine does not need so much timing. If your lap times are just as good with 34 as with 36deg, run 34deg.
Gives a little more detonation headroom. You don't want it to detonate when running hard @ WOT continuously
as opposed to a quick dyno test or a quick 1/4 mile drag pass. Excessive spark advance invites detonation.
What happens on a dyno test is not (exactly) the same operating conditions of when on track running.

[wyrmrider]

F-Bird strikes again
exactly
Dyno don frequently got the advance too much on our cars- early on while at Blair's in Pasadena
what fun

[rdkonkel]

Yes ,zero deck, .039 head gasket
Headers are 1-5/8 stepped to 1-3/4

[rfoll]

Yes ,zero deck, .039 head gasket
Headers are 1-5/8 stepped to 1-3/4

Did you cc it? The numbers don't quite add up, unless it has very small valve pockets.

[rdkonkel]

Supposed to be 76 cc stock, been cleaned up a bit so maybe .010/.020 off the heads