Initial Timing Advice

[Squirrely Brother]

I’m sure I’m doing something wrong, but this is what I came up with.

650 rpm 10
1000 rpm 13
1500 rpm 21
2000 rpm 25
2500 rpm 26
3000 rpm 28
3500 rpm 28

Mechanical ??? Don’t understand
Vacuum 22 @ 2500

 

[Squirrely Brother]

Just to clarify, when I connected the vacuum can and checked timing at 2500 it was @ 22

 

[Squirrely Brother]

I messed up with a typo. The vacuumed timing was 25 @ 2500.

 

[Squirrely Brother]

I just placed a hand vacuum pump on the canister and there was zero vacuum. I’m assuming it’s broken, but I don’t understand when connected to manifold why does the idle change?

 

[Matt69olds]

https://www.indianachevelles.com/in...1-article-ignition-timing-total-timing-method

Read this.

 

[Squirrely Brother]

@Matt69olds Thank you. I ended setting timing at 36 @ 2500 with vacuum plugged in a gauge showing 21 hg. I went for a drive and it scooted up to 65 smoothly and pretty quick, but it seemed like there was more to give. I’m going bump it up to 38 @ 25000 to see how it goes. Probably going to order a Summit 850001R distributor since the vacuum advance seems squirrelly. Appreciate your’s and everyone’s assistance. Have a Happy Holiday.

 

[Ricko1966]

I’m sure I’m doing something wrong, but this is what I came up with.

650 rpm 10
1000 rpm 13
1500 rpm 21
2000 rpm 25
2500 rpm 26
3000 rpm 28
3500 rpm 28

Mechanical ??? Don’t understand
Vacuum 22 @ 2500

Was this done with the vacuum can disconnected? If so you've got 18 degrees centrifical, all in by 3000. Set your initial to 14. Vacuum advance disconnected and pligged find an area with two land marks 1/8 mile or so apart standing start record your mph when you pass mark no.2 bump timing 2 degrees record, bump timing 2 degrees record, bump timing 2 degrees record. Now you've just set total for 32,34,36,and 38 one of those will have the best mph that's what your motor wants.when your done there we"'ll play with the vacuum can. When your done there we"'ll play with weights and springs

 

[Squirrely Brother]

@Ricko1966 The vacuum was disconnected and plugged. I will do as you state. I’m going to sound like a dumbass here, but set the initial timing at 2500 rpm or what rpm please. I learn best by sight and repetition, so I appreciate your patience with me being 8up.

 

[Ricko1966]

@Ricko1966 The vacuum was disconnected and plugged. I will do as you state. I’m going to sound like a dumbass here, but set the initial timing at 2500 rpm or what rpm please. I learn best by sight and repetition, so I appreciate your patience with me being 8up.

Initial is at Idle with vac advance plugged. Make sure your idle is low enough that the weights aren't adding advance like 800 rpm or less. Don't buy a summit distributor. It's going to be a 1 size fits all and not dialed into your needs. GM made many,many, weights, springs, distributor cams and vacuum advance canisters for a reason. That reason is 1 size does not fit all.

 

[Ricko1966]

Just reread a bunch of your stuff your mechanical is all in at. 3000 not 2500 so you shouldn't be setting anything at 2500 it's all going to be at idle or 3000. You need to check your timing with vac advance disconnected and plugged at idle. Then reconnected the vacuum advance to manifold vacuum,not ported vacuum and see how much timing the vacuum advance adds at idle. Post your numbers on the vac advance, I think you were checking it wrong.

 

[Squirrely Brother]

@Ricko1966 I’ll post the vacuum number. The other numbers were with the can plugged and port capped. I just followed the link instructions from Matt until I heard back from you.

 

[Squirrely Brother]

@Ricko1966 At 650 rpm the timing shows 21 for plugged and unplugged vacuum.

 

[Squirrely Brother]

@Ricko1966 I need to note I needed to push the fulcrum on the carb to get it to idle at 650. It didn’t want to idle below 725. I understand now I did it wrong, but it did have decent power and acceleration without pinging @ 21.

 

[Ricko1966]

750 is fine You just don't want to be trying to figure out timing. Idling so fast that the weights. are messing with your readings.Nothing changes When You hook up the vac advance? Are you hooking it to manifold vacuum? If you got 18 centrifugal and 21.static that's 39 it's in the ball park.If your sure you are hooking to manifold vacuum and nothing changes sounds like your vacuum advance can is dead.Buy an adjustable one.Dial your timing in 2 degrees at a time like I told you then add as much advance as you need to get 46.This is still just getting things close, then we gotta get things right.

 

[Squirrely Brother]

@Ricko1966 It was manifold vacuum. The front drivers side port on the Edelbrock 1406. I’ll drive to Summit on Saturday morning to pick up an adjustable can then install and do as you’ve instructed. Is a Proform or Summit good to go? Both are adjustable by allen wrench. I can’t thank you enough, but wanted to let you know I sincerely do appreciate you taking time out to guide me.