I'm thinking about locking the timing on my Duster race car (440/500, 260 @ 0.050 cam N/A 10.5:1 on eddy heads). The car sees some street time as well. I've got an MSD Digital 6 box that I think has a start retard function. Fuel economy is not an issue. Any thoughts as to how well it will work for normal street driving? My ultimate goal would be to put on a crank trigger to stabilize the timing

I have a crank trigger locked at 34 sr heads 10.25 comp drive it all over starts right up hot or cold. I have more problems with the junk ethanol gas boiling

Fixed timing is best, because every engine needs the exact same spark under all conditions.

I just don't understand why you would need to lock it out on a street/strip car I mean will it gain any performance?
I set my base at 23 and total at 34 all in by 1800 RPM and it runs perfect with my combo.

Gus

There is a need for a timing curve, especially street cars. It wouldn't be a good idea to lock it out. There are points in time when the engine could use less than maximum high speed timing.

24 base with 36 total. Big cam, not much manifold vacuum. What RPM are you able to get the thing to idle at? In gear? Drilled throttle blades or the throttle opened way up? If its all in by 1500 or 1800, why bother with idle problems?

I can lock it out, set the throttle blades where they're supposed to be in relation to the transfer slots, make it idle at 800 in gear with a big flat tappet or roller, great throttle response, runs great. Timing is rock steady at any speed rather than chasing the base around at idle with light springs. What am I doing wrong?

Not a thing IMO.

The car idles fine. That's not an issue. The reason I'm thinking about it is 1) I like simplicity on my cars 2) Locked timing will allow me to run a crank trigger. I love the precision of crank triggers. I cringe when I see timing flutter at WOT. Every car I've had has done a little bit of that. Even just a degree or two bothers me!

If you shimmed the dist shaft you wouldnt
see any flutter

I have a collar on the shaft that fits tight up against the drive gear. Is that the play you're talking about controlling? I've never shimmed a shaft before

I don't see anything wrong. I use light springs in my dist that has full advance all in by 1800 rpm. Basically I set my total at 36 as that's what my car seems to like best and let the initial fall where it does. Which on my car its got around 24 degrees at idle in park. It runs great like that and has no ping at all on 92 pump. I see some guys run locked out timing on their cars but I never have. But to be honest when you think about it the setup we run and guys like Gus which his sounds about like mine is not all that far from being locked out. Course we don't have to much timing when cranking the eng but once its running and we hit the gas we are almost at total timing right after hitting the gas pedal some. I like the ight springs all in by 1800 to 2000 rpm as it works nicely on my street driven car. Ron

I ran locked timing on my 11:1 360 on the street for years with zero trouble.

William Baldwin recurve's dist for a living besides his carb business. He says he has seen up to 40hp in a proper curve vs locked out. I would assume that would be in the middle of the power band thou. I would think more power in the mid band would cause the vert to hit harder helping 60ft?

Like Dwayne said, you're not doing anything wrong.
Locking it out works better as the engine gets wilder. Nothing wrong at all doing it on a street driven car. For a mild engine it may not have as much benefit.
No need for a start retard either...don't use it.
Crank triggers are so nice when setting the timing, the mark is rock steady.

Pretty much the same here.

So how much time do you think your engine spends under 1800 rpm on the street? Other than idling.

I don't see the need for the advance.

I think Mr Pbody is talking about shimming the distributor itself. Some of the stuff I've seen had .080-.090 slop in the distributor.

On the dyno with a customer supplied MSD that was wacky. It had .100 clearance.

Shimmed it to where it had about .010 and it was golden.

I have mine locked out with no issues. It is happier locked out. Whatever you do don’t use the start retard, it will kick back and play havoc on the starter and converter ring gear. If need be wire the ignition separate and spin the motor with the ignition off initially.

So, you’ve got your big lumpy cam and the accompanying super low vacuum, low gears, and a high stall converter.
You keep bumping up the initial timing and discover the vacuum goes up, throttle response gets better, idle circuit in the carb becomes more responsive.
You bump up the initial more, and get more of the same improvements.

As Chip said, if the combo is “wild” enough, you keep bumping up the initial, and limiting the sweep to keep the total where you want it....... and eventually you find there is no sweep anymore.

That’s how I came to it over 30 years ago........by making adjustments, driving the car and seeing if it ran/drove better or not.
More initial did everything better....... so I kept sneaking up on it....... more driving, more evaluating....... until there was essentially no “curve” left.
For the last curve I was at 30 initial/36 total, all in by 2200.
I locked out another distributor, swapped it out...... and it was marginally better, so I left it like that.

Very little. The reason mine is setup this way is to make sure it starts easy. 99% of the time it is at full advance.