Worried about timing advance... Is this safe?

[drobertson]

A while ago I built my 318 with a mild cam. I had it running at 14 degrees and it ran ok. I then tried advancing it to 26 degrees at idle and it runs great at that. Is that safe for a mild engine?
I'm not even sure how much advance there is under load but it runs good.

The engine is 8.6:1 compression, and has a cam with .454/.454 lift and 272/272 duration on both intake and exhaust. Stock heads with 340 valve springs, and edelbrock performer intake. Long tube headers as well. Has a 500cfm eddy carb but will be fuel injected as soon as my efi kit comes in the mail.

I'm not hearing any pinging, but I was curious if 26 degrees initial advance is risking anything. (I set the initial advance with the vacuum hose disconnected from the distributor, and then after timing I hooked it back up. Vacuum for the distributor is coming from the ported vacuum.)

 

[dla4567]

It won't hurt anything at idle, and if your not getting any detonation (pinging), it will probably be fine. But, you should determine what the timing is at full advance. It only takes a couple of minutes. I don't remember what the timing on my 318 ended up being but I'm sure someone here will know about where it should be.

 

[drobertson]

It won't hurt anything at idle, and if your not getting any detonation (pinging), it will probably be fine. But, you should determine what the timing is at full advance. It only takes a couple of minutes. I don't remember what the timing on my 318 ended up being but I'm sure someone here will know about where it should be.

How do I find full advance? Like what is the procedure? Thanks.

 

[dla4567]

Hook up your timing light, just as you would to check advance at idle. (Disconnect vacuum advance and plug carb port.) Then, with light on timing marks, increase engine speed until timing stops advancing. This is your full mechanical timing advance. Also if you note the rpms, this is your all in point.

 

[91r/t]

Most I have seen a street Mopar like is 36 total advance. I know my springs in the distributor on my 383 are full advance at 3000 RPM so I rev to 3000 and check timing at that RPM.....That will give you full advance. My 318 70 duster likes 12-13 degrees at idle. It is easier to accomplish with a dial in timing light so you can set the light at 30 and work from there to see where you are fully advanced. Make sure to undo the vacuum hose on distributor and plug the port on carb if you have a vacuum advanced unit.

 

[Darthomas]

If you get it dialed in nice and lean for good mileage, it will kick back and not want to start when good-n-hot.
Anything beyond 15 degrees advanced is asking for one issue or another.

In stock stuff, 13-15 degrees is the sweet spot.

 

[62 Dart Convertible]

How do I find full advance? Like what is the procedure? Thanks.

Like said above, to get ignition fully advanced, disconnect vacuum advance unit and with timing light on marker increase revs until it does not advance further.

To read you total advance in degrees you either stick a timing tape on your harmonic balancer - https://www.summitracing.com/int/parts/dcc-4529070

or use a "dial back" timing light - https://www.summitracing.com/int/parts/sum-g1059

 

[drobertson]

If you get it dialed in nice and lean for good mileage, it will kick back and not want to start when good-n-hot.
Anything beyond 15 degrees advanced is asking for one issue or another.

In stock stuff, 13-15 degrees is the sweet spot.

Well it runs like $hit with less than 23 degrees initial advance. It starts just fine when the engine is hot or cold.

 

[drobertson]

So what do you guys think my full advance should be?

 

[62 Dart Convertible]

as 91r/t stated above, 36 total should be about right....

23 initial (assuming your advance is working as it should) sounds a little excessive (especially if a stock dizzy) but if you are not getting pinging, who is to say it's too much?! It's too much when performance starts going backwards, engine pings or is a prick to start.

You really should know your total.

Before doing anything, I'd recommend you check your balancer TDC mark is correct. To do it you'd need an adjustable piston stop (made from an old spark plug) that screws into no. 1 spark plug hole. Then rotate engine by hand both directions (pull all plugs out first to make it easier), and mark the balancer with a pen where it lines up with timing case 0 deg mark when piston contacts stop. The TDC line on the balancer should be exactly in the middle of your pen marks. If not, your balancer needs replacing.

 

[kjalltrac]

My 8.3 comp 440 with xe484 cam likes about 20 deg initial and 39 degr full.
you can easy do 32-36 deg

 

[eric383]

If you don't have pinging and starts ok when warm (no kickback) I wouldn't worry about how much timing you have into it. If you have a dial back timing light you would be able to check how much advance you have at 3000 rpm. That is assuming the balancer marks and pointer line up at TDC. Just my 2 cents worth.

 

[drobertson]

If you don't have pinging and starts ok when warm (no kickback) I wouldn't worry about how much timing you have into it. If you have a dial back timing light you would be able to check how much advance you have at 3000 rpm. That is assuming the balancer marks and pointer line up at TDC. Just my 2 cents worth.

My balancer is accurate. I confirmed it by pulling off the driver's side valve cover, and slowly rotate the engine by hand until valve overlap in cylinder 1. That's TDC.

 

[eric383]

That's always good to know. It's time to play with the timing and tune for driveability as opposed to factory specs.