Moparts

When Should The Distributor Be Locked Out?

Posted By: cjs69mope

When Should The Distributor Be Locked Out? - 08/14/12 05:21 PM

Trying to find the best tune for my Motor
493 stroker with 250/260 @.020 and 630 int and ex lift solid roller .
When is it recommended to lock out the advance , Eng seems to like a lot of advance , currant set up is initial timing @ 24 and 10 to 12 deg mechanical all in by 2000 rpm. This is a 4 speed heavy b-body car.
Wondering if i should just do away with the mechanical advance and just set it to 34 or 36 deg locked down?
What advantage or disadvantage would this cause?
Thank you in advance for all advice
Cj.
Posted By: RemCharger

Re: When Should The Distributor Be Locked Out? - 08/14/12 05:56 PM

Looks like you have a streetish cam, probably no need for you, from my exp. anyway.
My 12.5 383 with 275@.050 needs lots just to run, but I still eneded up putting 6* back into the dist. locked out can be hard on pistons/pins/bearings, esp on street gas.
Posted By: Triple Threat

Re: When Should The Distributor Be Locked Out? - 08/14/12 05:59 PM

My 390" small block 263/268 @.050 cam

I have 16* cranking, 25* at idle, 34* all in by 2500.
Posted By: Thumperdart

Re: When Should The Distributor Be Locked Out? - 08/14/12 06:46 PM

My 12.1 comp. 470 is locked out at 34 degrees and have no issues but, I run two bad-ass gel batteries which seems to help..........
Posted By: sshemi

Re: When Should The Distributor Be Locked Out? - 08/14/12 06:51 PM

I see it like this, whenever you have an auto start retard and there is no chanse of detonation i would lock it.
Easier to tune carb and more vac for power brakes and should probably run a little cooler.
Posted By: Thumperdart

Re: When Should The Distributor Be Locked Out? - 08/14/12 07:07 PM

Quote:

I see it like this, whenever you have an auto start retard and there is no chanse of detonation i would lock it.
Easier to tune carb and more vac for power brakes and should probably run a little cooler.

The start retard made it harder to start and created more problems so I tossed it..........that was years ago.
Posted By: sshemi

Re: When Should The Distributor Be Locked Out? - 08/14/12 07:19 PM

Yeah i have used mallory boxes before that have worked very well but now i have a msd digital 6 box and the start retard doesnt work any good at all.
Posted By: Thumperdart

Re: When Should The Distributor Be Locked Out? - 08/14/12 07:30 PM

I just use the 6200 msd box.............not even a rev limiter so I added the seperate retard and that`s how it was RETARDED........would kick back and was hit and miss at best.
Posted By: radar

Re: When Should The Distributor Be Locked Out? - 08/14/12 07:32 PM

I moved the cranking to a seperate button and the key just unlocks my steering and turns on the ignition. I flip my key on, fill the float bowls, turn it off, crank it till it is spinning and hit the key again. Mine is 22* initial 34* total/ msd pro-billet. It doesn't kick back but when it's hot it cranks real slow with the key on.

If you have a high stall or big pressure bleeding cam it might be a lockout canidate?
Posted By: MR_P_BODY

Re: When Should The Distributor Be Locked Out? - 08/14/12 07:45 PM

If you get to a point where your only at about 5*
in the advance then go ahead and lock it out... but
a good curve is better IF you need it but it has to
be tuned in for your set up
Posted By: pleasantk

Re: When Should The Distributor Be Locked Out? - 08/16/12 06:48 PM

Just went through this with my new motor in the spring. It seemed the more initial I gave it the more it wanted (MSD).Finally locked it out at 36 and it was good except for hot starts. A friend suggested removing just one of the springs so it was retarded while starting and is all in at idle. Has worked gat all summer and is easy to check timing and no problems with hot starts. No retard box needed, no hacking into wiring and free to try!
Posted By: mopar dave

Re: When Should The Distributor Be Locked Out? - 08/16/12 06:58 PM

rule of thumb that ICE uses is cam duration 270*@50 or more lock it out.
Posted By: mshred

Re: When Should The Distributor Be Locked Out? - 08/17/12 04:27 AM

Quote:

Looks like you have a streetish cam, probably no need for you, from my exp. anyway.
My 12.5 383 with [Email]275@.050[/Email] needs lots just to run, but I still eneded up putting 6* back into the dist. locked out can be hard on pistons/pins/bearings, esp on street gas.



When you say that locking out is hard on bottom end parts, is that upon initial start up only? or at lower rpm's as well? Lower octane compounds these problems?

My cam is 240/248 at .050". Used to have the MP electric dizzy, swapped in a lean burn one locked out to 36 total. I have a Mallory hyfire 685 box, and I have all ten degrees of programmable start retard on currently, and the car starts fine. Two things that changed though was the car idles smoother (not sure the science of this) and it seems at lower rpms at part throttle acceleration that the car sometimes has a very slight surge.

My main reason for locking it out was for when i run the nitrous
Posted By: HEMIFRED

Re: When Should The Distributor Be Locked Out? - 08/17/12 05:13 AM

Quote:

Quote:

I see it like this, whenever you have an auto start retard and there is no chanse of detonation i would lock it.
Easier to tune carb and more vac for power brakes and should probably run a little cooler.

The start retard made it harder to start and created more problems so I tossed it..........that was years ago.



JUNKED MINE REAL QUICK

We seem to forget that Direct Connection solved hard starts by incorporating a second pick up set at an amount of advance for starting purposes. Once it fires flip the toggle and the other pick up goes to full advance .

here's the prototype for a s/b

Attached picture 7338601-SDC14188.jpgz.jpg
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