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Any Issues with Locked-out timing

10K views 21 replies 15 participants last post by  Motor Martyr 
#1 ·
I was thinking about locking out the timing on my car. The last several years its been just street driven, but I'm hoping to find some time this year to get a couple of outings down the 1320.

I'm using a 6AL MSD box, a 85551 Pro-Billet distributor and an MSD 8970 Multi-step retard box with a 25 degree retard start (which I will use).

I was wanting to cleanup the idle a little and looking for abit more low speed throttle response.

Is there any other issues with running locked out timing on the street other than starting?

Thanks in advance. :)
 
#2 ·
I just locked out the timing on my Camaro. same box and Pro Billet dist. I have 14:1 compression, and at least in my shop, it has no problems starting. I use a summit mini starter. I guess if the engine were real hot it may, but not so far. I run 37-38*. It idles MUCH better, I can't see any drawbacks. You do not have a vacuum advance, right?
 
#3 ·
Same box, same distributor, MSD crank trigger...locked at 37 degrees.
No problems starting...hot or cold. No start retard box either.
 
#4 ·
jbird said:
You do not have a vacuum advance, right?
Jay,

Correct, no vacuum advance.

I wasn't sure weather I would need the start retard hooked up or not, I figured I have it, might as well use it.

I don't have near the compression that you do, only 10:1. I'm also using a Tilton mini started with a 1000 cold cranking amp battery.

I was going to shoot for about 37 to 38 degrees locked.

Also..............if I do decide to lock the timing, I do away with the springs and weights right?
 
#5 ·
No Issues With Mine Locked Out At 38 Degrees. Msd 6al And Dist. And Timing Computer And Retard Control.
 
#6 ·
71454Chevelle said:
Jay,

Correct, no vacuum advance.

I wasn't sure weather I would need the start retard hooked up or not, I figured I have it, might as well use it.

I don't have near the compression that you do, only 10:1. I'm also using a Tilton mini started with a 1000 cold cranking amp battery.

I was going to shoot for about 37 to 38 degrees locked.

Also..............if I do decide to lock the timing, I do away with the springs and weights right?
Yes, look in your documentation for the instructions. It's an easy deal, but you do have to remove and reinstall the dist. gear. Not a big deal at all.
 
#8 ·
mines locked out as well, my start retard only retards 10* but i do use it.

2 possible drawbacks i noticed when i locked it out. The thing is harder to start when its cold and been sitting a while but not a big deal. The other thing is that if my battery doesn't have a pretty good charge it will just crank and never fire. Its not like other motors were if the battery is low and is cranking slow it will just fire right before the battery gives out. I got stuck in the staging lanes cause my bottle heater was on and took too much juice:clonk: . But it looks like you have a better battery so go for it, ill never run a curved distributer again.
 
#9 ·
I have mine locked out as well, 34 degrees. Idle quality & throttle response are great. No real issues with cold starts even though I have a retard box that kicked the bucket after only one year of service :(
 
#11 ·
I locked mine out, and the whole deal just became so much more stable, idled better, everything better except maybe gas milage. It is a breeze to put the timming light on it now. Just try it with a solid roller from a dragster motor with the weights jumping all over the place. Impossible to time.
 
#12 ·
I locked mine out one day at the track (MSD HEI Pro Billet) when I noticed it was about 15 mph slow. Turned out the weights were binding up so I just locked it out at 36*. Been running great for over 5 years since. The car idles rock steady now also. Throttle response didn't really improve, but I think it's in the carb. Oh, no starting probs either.... Kragen battery and Delco starter.
 
#14 ·
Pro67Chevy said:
I don't understand how a car idles at 36*. How is that possible?
Very simple and does so well.
Is your vacuum advance plugged into a manifold vacuum source? Almost the same results...with the engine at idle.
 
#15 ·
Car is not running yet but it will have no vac advance. I knew it bumped it a few degrees but I didn't realize it was that much. Maybe locked-out timing is worth playing with when I'm done.

And there is no pinging? I will be running 94 octane with 10.7 comp. closed chamber heads and small dome pistons.
 
#16 ·
i locked my timing out cause of how hi it idols. When i had a curve it was set at 21* initial, 38* in by 2500. The problem was that my car idoled at about 1250rpm out of gear and about 800 in gear and would usually die. this turned out to be that when it was in neutral the distributer would already start to advance cause the light springs, drop it in gear advance went away and the idol came crashing down. It may have just been older springs but i still won't go back

Locked it out and now idols at 1150 in neutral and 1100 in gear and no more 2footin it at stop lights.

No detonation since with this loose of a converter the thing can never be under much of a load until maybe 3500 anyways.

I think locked out is great if you have enough cam, but on a mild cammed motor i would imagine all advance could cause problems.
 
#19 ·
ProdigyCustoms said:
I run it locked at 39 on my 404CI street racer. Starts fine, no overheat issues even with a Meziere pump, filled to the bottom of the freeze plugs, and just a 28" fan with no shroud on a generic Griffin radiator
I think you could run a pretty good size lawn sprinkler system with one of those Mezeire pumps! Those things do pump some water!:D
 
#20 ·
i had my 468 locked at 34 deg. ran good and had good idle. how ever it seemed to lose some top end? didnt jive with my cam i suppose. hooked the vac back up. now for a related question...........dosnt vac drop off at high rpms retarding timing and enabling higher rpm? does locked timing counter act this process? just a thought.......could be wrong and propably depends on cam



thanks fellas
 
#21 ·
If you have a vacuum canister on your distributor, when your at highway speeds a carb vacuum line pulls more timing into your distributor. Its usually stamped at the diaphram the amount it will add. Because you are at light load you can add timing to help milage. This is how I understand it , I'm just a rookie and am working on a street strip 55 chevy. My concern with being locked at say 36 degrees would be not having the extra 15 or 20 degrees from the vacuum can? I'm going to have to find out because my new Pro-Systems carb has no vacuum ports .
 
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