Locked out distributor

Running a locked msd pro billet on my 12.5-1 493 . I have a digital 6 w start retard, but still get starter kickback and hard starting from time to time. Very annoying to say the least, but once started it runs awesome. Contemplating swapping distributor for a non locked version, or perhaps wire a start switch so I can get engine cranking first and then hit ignition. Built as a race car that wants to do some street cruising as well. Any thoughts?

I also found my MSD start retard very un-reliable. I was told it has to do with where the rotor lands when it stops, but I couldn't risk breaking the starter and went back to my usual.

Somtimes mine would work, somtimes it wouldn't....Hated it.

What setting does the retard default to?

Reasons to lock the distributor:
1. one less thing to fail
2. fewer questions
3. less maintenance
4. don't understand what an advance curve does
5. bought it that way

The best spark setting for mixed use is not, ever, a single position. Beyond a certain RPM, and assuming WOT, a single setting is very close.

Time to finally make the switch to a Holley Sniper. Then you'll have EFI, plus data logging and a fully adjustable timing curve including start retard built in.

Unlock the distributor and put the correct curve in it. Locking the timing out is wrong.

Somtimes mine would work, somtimes it wouldn't....Hated it.

Same!

Bought it that way thinking I had a start retard and it wouldn’t be an issue. Wrong!
MSD digital 6 manual says it retards timing 20 degrees. I guess I also planned for this car to be race only, but now
I’m getting some street use out of it.

Maybe when budget allows ..

I now have a Pertronix ignition and it has a start retard built in. I have not tried it. If what they say is true of the rotor stopping in the wrong spot, then this box probably would not be any different, but again I have not tried it. I always thought it was because mine was added on after the fact instead of built in.

Reasons to lock the distributor:
-Better Idle
-Easier to set total timing
-One less thing to go wrong
-Some cars really like it locked better than a curve.

Set the initial, idle timing, at or close to 14 to 16 BTDC and total of 34 to 36 BTDC and let us know how that works for you
I use the Mr. Gasket 96B springs (I hope that is the correct part number, maybe I should go look at some on the shelf, it is for GM distributors )

re- check the timing delay and fix that or [ unlock it.] ... with 12-1 comp ratio it will need a lot of starter to turn that. . i have used them both ways. a second switch will let you spin it over but, i have seen them hang up as soon as you flip the power on too... i would put in a curve...

That curve wouldn't even idle in my Hemi. Funny how everyone thinks the same curve works on every engine. Its just a starting point, and you need to work on it to see how the engine responds Each engine likes what it likes, and total and idle will be different engine to engine. We are finding our stroker wedge engines like right around 38* and my buddies 440 that went 6.19 last night has to have 40* in it....

Whats nice about a locked distributor is the idle generally will get better with more timing. To low of idle timing, and the engine will start and stall very quickly, never really getting a strong idle. I find most of my engines like at least 20* in them. Hemis really like 25 at idle. Wedge we find 18 is usually fine. I like to close up the curve as much as possible to where its almost hard to start.

I use a stock disributor to trigger a 6AL. I put the lightweight Mr. Gasket 925B springs in it. Essentially they act like a start retard as once fired it has all 36° of total timing. Works great!

Agreed, let the engine tell you what it wants.

The issue with locked timing is you have no idea what your total timing is. Unless you set total at WOT. Then the curve won’t be correct if you don’t account for box retard.

Big lumpy cams in a carbureted deal get locked.

You put the MSD distributor in it with the big bushing and light springs. And still have to make it idle at 1000 for it to stay running. Try to slow it down and the timing backs down, slowing it down even more until it won't run. Or it stalls when you drop it in gear. So you wind the idle up to keep it spinning fast enough to keep some timing in it so it will stay running.

Make a bushing or whatever, to get enough timing in it to idle and it ends up at 25, at least. Well I'm only running 34 and it's all in at 1500. Nothing happens below 3000 in my world, so why bother.

I've done the light springs, make a big bushing, drill the throttle blades, fiddle around with it, and every time I put a few more degrees of base timing in it, it likes it. So...Lock it, set it at 34 or whatever. It will idle at 800 in gear. Response will be sharp and crisp and it sounds happy. Every time.

And I've gone back and tried it the other way because "it's not supposed to be locked and it should have a curve". And the engine tells me "gimme timing".

Anything of mine, or anyone else's who spends the money and lets me, gets a crank trigger and a distributor that just spins the rotor around the cap. Easy, effective, simple.

What do you consider a big, lumpy cam? Asking because I’m not sure how to understand how to determine that.

My 499 840 hp idled at 650 with instant throttle response in gear, timing all in at idle, but was maybe 10 degrees starting so it wouldn’t kick back. 7320 dominator. No little stuff in this engine, I could put in in gear, get out and walk around and it would just sit there. By the way it’s an engine not a motor, a motor is electric.
Forgot to add total was 37, never moved it to see if it was better anywhere else.

How you going to learn if you don't test, especially testing at a good track

Thanks for all the great responses. Here’s a little more info:

493 w 12.5-1, Indy -1 heads, Indy single plane, Cam is 268@.050 roller and 1150 Dominator . 5200 8” converter and 4.10 and 295/65 Drag radial. The MSD digital 6 doesn’t have a start retard adjustment , it is supposed to retard timing 20 degrees when the retard function is chosen. It’s either on or off.

I’m seeing pros and cons, and the one pro for sure is that it idles great and very crisp throttle response w locked full timing.

For me the main con is the occasional hard start.

Does anyone have success with the two switch start deal?
How about a higher torque starter? Currently using a summit mopar mini starter

Yes I have success with the two switch deal. Sometimes when hot it still rolls over slow but once rolling throw the ignition switch. Thought about wrapping the starter to keep it from heat soaking. Stock 90's started can't remember which one..

Hundreds of millions of engines made with curves since the Model T (manual advance).
Too bad they didn't realize you don't need it.

Whether you believe in it or not, physics is always there.

All I use to do was to set the timing so it would idle then set it for total timing.. the engine
only had 2 speeds.. idle and WOT.. it would idle at 900rpm and I could drive it in the pits..
as soon as the engine started it was 200 rpm below where the curve would come in.. from there
it was 35*

turn off the start retard and you problems will go away. I've been down that path before.

That was where Kenny said to set it from all the dyno pulls. When I go to the track I concentrate on winning the next round, if I had time I would fiddle with it but the big thing is reaction time and the number. If I felt it needed anything I would look into it. The one thing I learned in all these years is the winners don’t fiddle with the car on race day the ones who do are on the trailer.

Comparing a custom, modern street/strip performance application to vehicles built for the masses is the most retarded thing I've seen on here. Pun intended.

Agree, poor comparison using OEM engines needs vs built street/race engines even if the "physics" does'nt change.

Locked out, start retard, crank trigger.

280 @ .050 580 inch Hemi, never an issue.

I was running a locked-out MSD Pro-billet distributor on my RB. I swapped it out with one of the recently released Progressive Ignition bluetooth programmable distributors. With some guidance from AndyF, I ended up with my own custom ignition table that lets the motor crank at a low timing setting, but as soon as it starts the timing goes to 34* by 750 rpm.

The reason I switched was to add the adjustable vacuum advance to my set-up. Now, at cruising RPM I have 44* total. Attached is an example of one of the tables I tried before settling on what I just described. It's for illustrative purposes only. The numbers in the left colum are MAP readings, which account for atmospheric pressure.

Essentially, it gives me start retard, locked-out timing and vacuum advance. It also lets me see what the timing is doing in real time and make changes on my cell phone. So far everything is working flawlessly.

This could all be resolved by a simple test with an in-cylinder pressure transducer. It's been done, by F1, Ferrari, Mercedes, and every auto manufacturer.

I'm not dealing with OEM spec engines much. An engine that operates primarily at part throttle from idle to 3000 RPM is a different animal from a race deal that's either on or off. Or even a race deal with tags that idles around on the street some on a Saturday night.

Big, lumpy cam = >240*-245* @ .050. <10" vacuum. Usually a roller of some type.

An electronic means of retarding timing when starting, high gear retards, pulling timing at the hit on a big power, suck track deal, are all great ideas to be able to do. But some of us are doing the KISS with just a 7AL with a crank trigger and a carb deal. So basically I don't need a curve. Also, race cars should have separate start and ignition switches to be able to spin the engine with the ignition off anyway. Easy to do, even if you're still using a stock ignition switch.

Having the thing fall back 15* or 20* from total timing usually ends up making you open the carb to make it idle. Now you've upset the throttle blade/transfer slot relationship or drilled holes in the blades. Either way, you're doing stuff to the carb you wouldn't have if it had the timing in it. I typically set the throttle/transfer slot relationship by eye, install the carb and keep my fingers off the idle speed screws for all but fine adjustments. If it won't idle, I fix the reason for it. Maybe a little air bleed somewhere.

Big roller, 800 RPM in gear without having my foot on the gas. Plugs a little hotter than most run, Sit and idle like that all day if I want.

So you go from touting OEM "solutions" to that of multi-million dollar race teams?!

I knew there was a reason I had you on ignore...

Thanks for the explanation.

Here’s what I’ve done so far just to try some if the ideas that have been suggested:

I switched the digital 6 setting back to standard (no start retard) and starter kicked back when I tried starting.

Wired ignition on a toggle, spun engine w key switch , then added ignition on and...kick back

Went back to start retard on box, spun engine w key, added ignition on and...it started no kick back

Took car out for a nice spin around town, and parked it for 20 minutes. Tried to restart w spin engine first method and it fired up again. I’ve had similar results w just normal key and ignition on at same time, using start retard. Would still get occasional starter kick back. I don’t want to get too excited about two consecutive starts without kickback. Time will tell if the 2 switch method is the winner.

Has anyone tried a higher torque starter to deal w this issue?

No, someone I know.

Please continue to make yourself ridiculous.

Removed duplicate post.

There are really 2 very different answers to "locked: Y/N?".
1. is the position of the piston when the spark kernel begins to expand away from the ignition source. In addition to compensating for the time in milliseconds balancing piston accelerating away from TDC to advancing flame front (which dies out after perhaps 3,000 RPM), the remainder is based on the cylinder pressure (combustion, not CCP), A:F mixture, droplet size, fuel chemical characteristics, VE, and how many intermediate stages of combustion take place (before final conversion to water and CO2), and boost.
2. is how many of these are relevant to a maximum effort engine that only needs to start, idle (more or less), stage, launch and WOT. Sometimes this answer is so close to "only 1" that the exceptions are more trouble than they're worth. I've never seen an engine with idle quality exactly the same with 15° and 40° spark; the idle speed may not differ significantly but the spark position can be selected by choosing the LOUDEST position.

Tony, I have a slightly used MSD starter saver sitting in my cabinet that you can have if you want to try it. I don't need it anymore since I went digital. I assume this is the same module that you are currently using? Maybe yours is flaky so swapping in another one might eliminate that variable. No guarantees that this isn't also flaky. I never fully tested it. We used it a few times on the dyno but couldn't confirm that it was really working so we switched over to the method of spinning the engine before hitting the switch. Eventually we just went digital and EFI and built the start retard right into the map. Shoot me a PM if you want this MSD module.

That looks good to me. That table gives you everything you wanted. The programmable distributor is another option for Tony if he doesn't want to move all the way to EFI at the moment. Glad to hear that solution is working for you.

Friend of mine just did the same and his timing moved from 38* to 42* . Doesn't drag the starter any more and the engine just does everything better now. He has a chevy with a 505. Too many plug ins and things to go wrong. Fires immediately now. Runs on E85.

Thank you Andy, I might take you up on that. I’m currently using the digital 6 which has a built in start retard. I actually sent the box in to msd because I thought it was faulty. They tested the box and said it was fine. Embarrassingly enough, I bought a new digital 6 while that box was being serviced. (I was ancy and wanted get back on the road). The new box did the same thing!!..worked some of the time.
Hit me up anyone who is interested in a good deal on a like new digital 6 box w clean bill of health from MsD. (Can’t make any promises on the start retard function!!)

The 2 switch start seems to be working at the moment , but I’ll keep you posted. Thanks again, Andy

I ended up making a stock Mopar low deck electronic distributer work very well in my old pump gas Duster by shortening up the advance slots so it had right at 18 crankshaft degrees of mechanical advance, which is nine distributor degrees, all in by 1200 RPM. It would start well and idle at 850 RPM in gear with 16 degrees BTDC, a fairly big solid roller cam (260@.050 int. with 266@.050 on the exhaust lobes installed at 106 ILC) ground on a 108 LSA.
That car and motor made me very happy, made some money at the track and had a lot of fun with it on the street

I don't doubt it, Cab. Id probably be fine w an advance curve too, but I need a guru like yourself to get it all dialed in!

What springs did you use so the advance to be all-in at 1200 but none at 850 (or very close to it, since otherwise the idle would be unstable with changing advance)?

Back then I used a pair(the thinnest, weakest set) of springs from a Mr. Gasket kit, I don't remember the kit number now though
Those springs would pull the advance weights back under 1100 RPM and be at full advance by 1300 RPM which made the motor start well and t was like having the distributor lock out almost.
It took me a while to figure out how much initial to set that motor up with so it would idle well and not kick back on the starter, it would start to kick back at 18 BTDC would really kick back at 20 BTDC 13 BTDC or less made it not idle well

You can maybe try contacting Joe White and have a custom mopar one set up to the curve you need. He does great work and many people have said very good things about his distributors. Joes mopar distributor restoration on facebook is where to find him. I had him do a cable drive electronic one for my 493 and am very happy with it

I've never done this, but these discussions usually make me think.

If a person was trying to thread that needle, get the engine to spin and fire at one RPM and timing setting, then have the ignition go to near total or total when it starts so the dumb thing will idle and respond... why not use distributor advance flyweight weights to adjust it?

Springs only give you a few options. Weight changes can be infinite. They do it with clutches.

Add a dab of spot weld with a MIG out on the heavy end of the weight. Get too much you can grind it off. Or drill and tap some machine screw holes and add screws and washers. More weight should bring advance in quicker. Keep the flyweights equal.

I would want to do this on a distributor machine. Probably be a PIA trying to do it on an engine.

TonyS451 I sent you a PM. easier to talk on phone than type it out.

Tony I fought with this a few years ago after changing to a digital 6 plus box from a old analog 6AL. Mine would kick back on the starter about 1 in 4 starts.

With the digital 6 box and HVC coil I had NO improvements just shorter cap and rotor life and shorter plug life on a indy headed 12:1 427cu in small block on e85.

I went back to the analog MSD 6AL stating issue went away, cap and rotor life improved, same ET and MPH. My personal opinion is the Digital 6 box is a POS.

Try something else

I guess every engine combo is different as to what it "likes".
My 451 (currently iron-head 10.3:1) doesn't fight the starter hot until 24 degrees initial.

So I ended up with one super-light spring, and one OEM heavy spring with loop in an OEM reluctor-pickup distributor.
This cranks at about 16 initial for easy starting, immediately goes to 27 at idle (1100-1200 rpm), then a slow increase to 35@4000 (as high as I've checked). The rotor tower is an 11/22 degree unit, so max advance is limited to 16+22 = 38

Since I drive it on the street, I also use vacuum advance, something like 15 extra degrees at a 15" Hg. cruise. Obviously not a factor at starting or WOT.

I've had a couple others say the say thing.. I do have a 6al sitting around... Did you also use the separate starter saver?

I use an Ice Ignition system with the volt booster. It is an inductive system and the booster keeps 16volts at the coil. It is a 7amp box with a two step and 10* start retard. I have a short curve in it, 30* at 1400rpm idle and all in at 36*@2500rpm. Works really nice like that. If i lock it out i sometimes get a kick back when hot and the timing retards with rpm about 3 or 4*, Its the nature of the beast when using only a distributor. Check yours, i bet it does the same at about 2500-4000rpm. Put a crank trigger on it and timing will be rock steady at any rpm and the timing has to be locked with this system. Hope this helps

What affects "fighting the starter":
CCP
Flywheel or converter weight (actually inertial mass)
Number of cylinders
Rod ratio

There is also another "RPM vs. spark position" in addition to centrifugal with vs. spring tension: tha shape of the weight. Examine a GM (easier to find) plot of engine speed vs curve and you'll notice that the curve is distorted (made non-linear) by the point where the weight’s concave radius contacts the center plate, which changes as the weights move. The weight normally acts against the gradually tapered side of the center plate. However, at very high RPM it continues to advance at a much slower rate, which may not be detected but may be enough to cause damage.

No I didn't, my combo did not care care, normally locked out at 34btc.