Locking Out Advance

BlueOval Ralph · 07-03-2012, 06:52 PM

Lazy mans way just start cranking the engine then turn ign on.

Quote:

Originally Posted by Phillip marvetz

You might want to find a ignition box that will retard the timing when cranking to start also.

FSA1673 · 07-03-2012, 09:13 PM

I have a MSD digital 6 plus box with a 20 degree start retard option. That should help with the starting. I want to run 36 degrees timing. I welded it in the full advance position but I now think my distributor may be out of phase causing some ignition issues.

Can you check the phase of the distributor by turning the motor over by hand? I have an old MSD HEI cap with the center cut out and a fully degreed ATI balancer. With the engine running it is showing I have 36 degrees with the light. But when I turn the engine to 36 degrees by hand the rotor and the cap do not line up perfectly. They are rougly 15 degrees off.

Any thoughts?

R. Thorne · 07-03-2012, 10:16 PM

MSD makes an adjustable rotor you might consider. Don't know if it will fit an oem distributor, though.

Ed Wright · 07-03-2012, 10:28 PM

Might try turning the distributor until the rotor is aligned with the cap correctly, then useing a hand held vacuum pump on the vacuum advance until the timing light shows 36 degrees. Make a note of the vacuum required to get 36 degrees. Shut it down, pull the vacuum advance, pull that much vacuum on it, and tack weld it in that position. Put it back on the distributor and recheck the timing and rotor/cap indexing. If it checks out, pull the vacuum advance back off, finish weld it, and cut the vacuum chamber off if you want. Might be worth a try.

Mark Yacavone · 07-03-2012, 11:10 PM

Turn the damper until the rotor starts to move..then turn it the other way until it moves again. .See how many degrees of slop you have in the chain and other clearances.
You DID say it was Pontiac, right ? LOL

07-04-2012, 11:31 AM

When I had my G/SA car. I used to take the stock HEI unit and weld up half the advance slot, then use the lightest spring. The car always started well, and total timing would be in around 1500. Simple modification, cheap, and very effective. 455's don't need a bunch of timing anyway.

Ed Wright · 07-04-2012, 11:37 AM

Back when we used points ( I still had brown hair, and all of it) I used no springs. Start it, small whack of the throttle and it was at full advance. Drag of points pulled it back at start up.

FSA1673 · 07-04-2012, 11:50 AM

I already locked out the vacuum advance when I built the car and cut off the canister. But that is a good idea if I still had it, very clever.

I used to run mechanical advance in the ditributor with light springs but I installed a MSD digital 6 plus box and wanted to try the timing locked out, to see if there was any performance advantage, and then later try the high gear timing retard. Box has a 20 degree start retard function so starting should not be an issue with 36 degrees

I will check the slack in the chain but I do not think there is much if any there. Will see tonight.

Will buying and MSD distributor fix all this? I liked the idea of the HEI with the terminals further apart rather than the MSD unit which are closer. But it is not firing properly with the rotor being out of phase.

Combo is 1971 Pontiac 455 HO if that makes any difference.

R. Thorne · 07-06-2012, 01:33 PM

Another option, fabricate a bracket for a threaded rod, bend rod to attach to the advance plate and mount to the original mounting holes for the vacuum advance, adjust for proper phase as Ed suggested and double nut it in position. Ron.

07-03-2012, 09:13 PM	#2
FSA1673 Junior Member Join Date: Jan 2010 Posts: 83 Likes: 0 Liked 12 Times in 6 Posts	Re: Locking Out Advance I have a MSD digital 6 plus box with a 20 degree start retard option. That should help with the starting. I want to run 36 degrees timing. I welded it in the full advance position but I now think my distributor may be out of phase causing some ignition issues. Can you check the phase of the distributor by turning the motor over by hand? I have an old MSD HEI cap with the center cut out and a fully degreed ATI balancer. With the engine running it is showing I have 36 degrees with the light. But when I turn the engine to 36 degrees by hand the rotor and the cap do not line up perfectly. They are rougly 15 degrees off. Any thoughts?

07-03-2012, 10:16 PM	#3
R. Thorne Member Join Date: May 2009 Posts: 183 Likes: 73 Liked 101 Times in 34 Posts	Re: Locking Out Advance MSD makes an adjustable rotor you might consider. Don't know if it will fit an oem distributor, though.

07-03-2012, 10:28 PM	#4
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Locking Out Advance Might try turning the distributor until the rotor is aligned with the cap correctly, then useing a hand held vacuum pump on the vacuum advance until the timing light shows 36 degrees. Make a note of the vacuum required to get 36 degrees. Shut it down, pull the vacuum advance, pull that much vacuum on it, and tack weld it in that position. Put it back on the distributor and recheck the timing and rotor/cap indexing. If it checks out, pull the vacuum advance back off, finish weld it, and cut the vacuum chamber off if you want. Might be worth a try. __________________ Ed Wright 4156 SS/JA

07-03-2012, 11:10 PM	#5
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,821 Likes: 2,910 Liked 5,132 Times in 1,957 Posts	Re: Locking Out Advance Turn the damper until the rotor starts to move..then turn it the other way until it moves again. .See how many degrees of slop you have in the chain and other clearances. You DID say it was Pontiac, right ? LOL __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

07-04-2012, 11:31 AM	#6
Todd Hoven Guest Posts: n/a	Re: Locking Out Advance When I had my G/SA car. I used to take the stock HEI unit and weld up half the advance slot, then use the lightest spring. The car always started well, and total timing would be in around 1500. Simple modification, cheap, and very effective. 455's don't need a bunch of timing anyway.

07-04-2012, 11:37 AM	#7
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Locking Out Advance Back when we used points ( I still had brown hair, and all of it) I used no springs. Start it, small whack of the throttle and it was at full advance. Drag of points pulled it back at start up. __________________ Ed Wright 4156 SS/JA

07-04-2012, 11:50 AM	#8
FSA1673 Junior Member Join Date: Jan 2010 Posts: 83 Likes: 0 Liked 12 Times in 6 Posts	Re: Locking Out Advance I already locked out the vacuum advance when I built the car and cut off the canister. But that is a good idea if I still had it, very clever. I used to run mechanical advance in the ditributor with light springs but I installed a MSD digital 6 plus box and wanted to try the timing locked out, to see if there was any performance advantage, and then later try the high gear timing retard. Box has a 20 degree start retard function so starting should not be an issue with 36 degrees I will check the slack in the chain but I do not think there is much if any there. Will see tonight. Will buying and MSD distributor fix all this? I liked the idea of the HEI with the terminals further apart rather than the MSD unit which are closer. But it is not firing properly with the rotor being out of phase. Combo is 1971 Pontiac 455 HO if that makes any difference.

07-06-2012, 01:33 PM	#9
R. Thorne Member Join Date: May 2009 Posts: 183 Likes: 73 Liked 101 Times in 34 Posts	Re: Locking Out Advance Another option, fabricate a bracket for a threaded rod, bend rod to attach to the advance plate and mount to the original mounting holes for the vacuum advance, adjust for proper phase as Ed suggested and double nut it in position. Ron.