Locked timing

[OSDart]

What are the pros and cons of running locked timing on the street? Personally, I can't see starting a hot, 11-1 comp, bb with 34° timing without some kind of timing retard system.

 

[Canyon707]

its in race mode@ 34 degrees. A lot for street driving IMO

 

[OSDart]

Canyon707, I agree. 34° is probably too much for a street only cruiser. However, it's either good idle timing or WOT timing set around 30°-32°. This 493 big block with a fairly radical cam idles clean with timing set at 18° BTDC. The MSD Pro-Billet dist limits a 18° advance with the (largest) black bushing installed. That's a total of 36°. Way too much. If idle timing is set at 12°-14° idle quality suffers.

 

[lewtot184]

use a start retard or don't lock the timing.

 

[LemonWedge]

Why exactly do you guys think 36 is too much "for the street"? The right timing is the right timing, no matter where you are driving the car. I run 18 initial plus 18 mech. For 36 degrees total with no vacuum advance. My curve starts at 1200 & all in by 2600 ... plenty of street miles and on pump gas.

Wherever the motor runs best is where the timing should be. For most BB's that's between 34 & 36 total. Now, back to the OP, I would not advise locking out timing for a street car for a number of reasons. But that really has nothing to do with where the total should be.

 

[Zeppelin264]

I'm running 18 at idle, right off idle it jumps to 38 for cruise and then WOT is at 36.

Of course I'm punching in these numbers in the hand held and running a hall effect sensor for timing.

With the Holley EFI you can set cranking timing and then set idle, cruise and WOT to whatever you want for "locked". Works great!

 

[PurpleBeeper]

To OSDart, I think you've already figured out the "cons" (too much advance to start without a timing retard). Pros - to help an engine idle at a reasonable rpm that has a HUGE cam in it. I believe you can use the "lean burn" distributors which are timing locked from the factory if I remember correctly.

 

[OSDart]

A few engine specs: 4.350 bore, 10.85 CR, 4.15 stroke, Indy EZ1 cnc ported, duration 260@ .050, 108 LS, Holley 850 hp(Dominator 1050 for the strip), TTI 2", 3500 stall, 4.10 rear.
On 93 oct non-ethanol fuel, 18° idle timing is fine. Total 36° seems too much for street. Just doesn't sound or feel right.
Strip times are fairly good with the Dominator and a timing change. 6.80's with tire spin!

 

[Zeppelin264]

My old distributor was pinging at 34 degrees and when I inspected it closely it looked like the rotor was firing late and arching backwards. I would check rotor phasing for sure. Look at the cap/rotor and see if one edge is all burnt up while the rest of the cap/rotor looks fairly new. That could also causing a detonation situation.

 

[Dodge 330]

I run 36° on the street and never have an issue. I have the 925-B Mr. Gasket springs in a stock Mopar electronic distributor. It's pretty much all in at 850 RPM so the springs only serve to retard during startup. It is, for all intents and purposes, locked at 36° while running. 10.5:1 CR and starts instantly every time! I would recommend a mini starter if you don't have one. It still gets 11mpg with no vacuum advance. I've thought about hooking it up and doing a mileage run..

 

[OSDart]

I did notice a small amount of rust like substance on a couple

 

[OSDart]

Sorry bout that. Rust like substance under rotor. Nothing big.

 

[condor74]

I don't run a locked timing in my race car but I do have light enough distributor springs that it is all in by 900 rpm. I idle at 1000 or so with my 340. set at 34 degrees total.

 

[Endangered Species]

I don't run a locked timing in my race car but I do have light enough distributor springs that it is all in by 900 rpm. I idle at 1000 or so with my 340. set at 34 degrees total.

Same here. We unlocked our a few years ago, and put the MSD light springs in it.

I've hears too many stories about starter snouts getting ripped off because of kick back at 35 deg and high compression. Not worth it.

 

[mopar 3 B]

To OSDart, I think you've already figured out the "cons" (too much advance to start without a timing retard). Pros - to help an engine idle at a reasonable rpm that has a HUGE cam in it. I believe you can use the "lean burn" distributors which are timing locked from the factory if I remember correctly.

Also two triggers one for run and one for start.

 

[OSDart]

I've got the MSD 8546 set up with a light silver, light blue and black bushing. Idles at 950 rpm @ 18° timing. Advance starts around 1100 rpm and all in at 2125 rpm. Timing jumps to 39° @ 4000 rpm. I'd just like to limit the WOT timing to around 32°- 34°.