Benefits of using a start retard and pinning the distributor?

[Yellow Truck]

Chris - what I'm really looking for is a good explanation of how timing really needs to behave when compared to engine load and speed characteristics.

I recently read an article that claimed you need more advance at cruise when the engine is essentially running lean (high vacuum and mostly closed throttle relying on the idle circuit for fuel) than you do at WOT where you are getting lots of fuel and flame front moves more quickly.

It really got me thinking that I don't really know much about how spark timing, fuel density, engine speed and vacuum all interact.

[cjshaker]

FWIW - I haven't had any issues with MSD parts.  I use their pickups instead of Ford type if I run a Duraspark type distributor.

I wish I knew what has caused me to replace 4 MSD pickups in as many years. Box wired directly to the battery with a cut-off switch, pickup wires shielded and routed away from any heat or electrical interference areas. It always comes soon after I notice a momentary blip on my Autometer tach, where the needle drops for a split second like there was a single misfire. Whenever I see that happen, I know it's coming soon. Last time was after the FE Reunion; car ran perfect at the Reunion, but I noticed a blip on the return road on one of the last runs I made. Next time the car was used was at a UMTR race just 2 weeks later, went to fire it up to pull it out of the trailer, and nothing. Same scenario every time. It's getting really old. I have two MSD billet distributors, both do the same thing, although the distributor should have no bearing on the pickup surviving. I have to carry a spare distributor AND a second spare pickup (a backup to my backup )
Not trying to derail the thread...

[Yellow Truck]

FWIW - I haven't had any issues with MSD parts.  I use their pickups instead of Ford type if I run a Duraspark type distributor.

I wish I knew what has caused me to replace 4 MSD pickups in as many years. Box wired directly to the battery with a cut-off switch, pickup wires shielded and routed away from any heat or electrical interference areas. It always comes soon after I notice a momentary blip on my Autometer tach, where the needle drops for a split second like there was a single misfire. Whenever I see that happen, I know it's coming soon. Last time was after the FE Reunion; car ran perfect at the Reunion, but I noticed a blip on the return road on one of the last runs I made. Next time the car was used was at a UMTR race just 2 weeks later, went to fire it up to pull it out of the trailer, and nothing. Same scenario every time. It's getting really old. I have two MSD billet distributors, both do the same thing, although the distributor should have no bearing on the pickup surviving. I have to carry a spare distributor AND a second spare pickup (a backup to my backup )
Not trying to derail the thread...

I never got more than 15 minutes of run time on my MSD billet distributor, but what made me absolutely give up was the insane conversations I had with their support people. First the told me it was bad, but they couldn't send it back because the shaft had been drilled for the gear, and they didn't have any shafts. When I asked them to just send me a new one, they told me they didn't have any new ones in stock. Then suddenly there was nothing wrong with the one I sent in, it had never failed, and they sent it back. It ran for 4 minutes before it failed. I sent it back and I had another series of insane conversations before I gave up and returned it.

[6667fan]

If you keep the MSD you have the option of decreasing the initial and getting back to the total you want via replacing the bushings in the distributor. If you bought it new there would be included a small bag with springs and bushings. Some engines/battery combos can struggle with 26 degrees of initial timing when it comes to hot starting. I run 18/14 in my combo but have very good heads which allow for less total than some hi-po FEs.

JB

[Yellow Truck]

If you keep the MSD you have the option of decreasing the initial and getting back to the total you want via replacing the bushings in the distributor. If you bought it new there would be included a small bag with springs and bushings. Some engines/battery combos can struggle with 26 degrees of initial timing when it comes to hot starting. I run 18/14 in my combo but have very good heads which allow for less total than some hi-po FEs.

JB

I hear you. I returned the MSD long ago. Only being able to drive a couple of miles on each distributor was a little inefficient. The Ford Duraspark provide similar options. I was able to get the initial it liked (around 26) and total of 34. We had to modify the plate a little to stop it at 34 because with initial of 26 it put total out around 39.

The question I'm really asking is - what is the use of initial vs total in getting optimal engine performance? The idea of pinning the distributor to the total timing and adding start retard is what got me thinking, and made me realize I didn't really understand what the engine needs under different load/rpm conditions.

[351crules]

i lock out the distributor out as well....

[GerryP]

You are at the point where you need to just go ahead and do it.  See what happens.  If the engine is not happy, then put it back to where it was.  That is how tuning works.  Simple, no?

[Yellow Truck]

You are at the point where you need to just go ahead and do it.  See what happens.  If the engine is not happy, then put it back to where it was.  That is how tuning works.  Simple, no?

I would say yes and no. Since some things are basically free, and some require buying expensive parts, the former are the yes, the latter are the no.

[frnkeore]

I also like to lock the ignition at total advance. I've near understood why you need any "curve" on the ignition, in a race application. They don't run worth a darn at lower speeds, anyway.

If you have enough overlap on the cam, it will also turn over and start easy, if not you need more cam

[GerryP]

...I've near understood why you need any "curve" on the ignition, in a race application. They don't run worth a darn at lower speeds, anyway.
...

You don't.  It's a foolish waste of time to set one up.

[Yellow Truck]

Just for context, I am looking at it for a 4WD pickup truck with a 445 with 234 and 240 durations at .050. Clearly not a racing application.

[plovett]

Oops.  Wrong thread.

paulie