How much timing advance is too much?

[Fern]

Everything I read says 35* of total timing on a 440 is max. But can you go over that  if it dosent start to detonate?
Can you advance the timing until you start to hear it ping and then stop there?
I ask because if I set my initial timing at 15* it gets up to about 39* all in. If i set initial lower to stay at 35*(all in) I cant get the car to start. I know its the distributer's curve, but dont want to buy a new one.

[71383bee]

Depends on the motor and all of the parameters of the components.

34 to 36 total is typical. The thing is with vacuum advance it's not uncommon to get above 40 at part throttle.

You can have the distributor recurved for your application.  I had mine done by Joe White. He's on Facebook and runs a distributor rebuild business. I had 2 small block dizzy's done and he did an outstanding job. It's worth looking into.


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[torredcuda]

All you need to do is weld the slots in the advance plate to shorten them thus limiting the amount of advance, there are also plates you can buy for this.

http://4secondsflat.com/Mopar%20Mechanical%20timing%20limiter%20plate.htm

[usraptor]

Like 71383Bee stated, it depends.  I don't remember off the top of my head what my initial timing is on my built stroker 440/512; I think it's  16 or 18 degrees, but I know my total timing is 36 degrees.  Are you still running points or  have you upgraded to an electronic dist?  Several retailers sell them and you can get them for under $200 if you shop around.  My understanding (I may be wrong) is that your timing will go over 36 degrees with the vacuum advance but as long as you total timing is 36 degrees or less with the vacuum advance disconnected, you are fine.  Here is an excellent article that explains how to set the timing.  If you do a forum search I think Chryco also has a post on it if I remember correctly.
http://tvmoparclub.com/files/tech/Mopar%20Timing.pdf

[RUNCHARGER]

36 total is usually where they are happiest. Limiting advance so you have more initial will make the engine "snappier" and usually idle better. Vacuum puts it into the 40's and 50's sometimes and will increase fuel mileage and burn the fuel better.

[MoparCarGuy]

I second the http://4secondsflat.com website. Owner is Don Gould.
Tons of technical info to help you with your timing.

[71383bee]

Bottom line is you need a recurve and there are several reliable sources that do it. I've used don too and he is very knowledgeable but he will try to sell you everything in his shop while on the phone with him.   

If you just need your dizzy done joe is a great source. For my 2 distributors it was 325.  My stock 73 looked like I pulled it from a dumpster and he completely disassembled it, cleaned it, installed new internals, and custom set the mechanical for 18 initial and 36 total. The second was a firecore I had from rev n ator that he pulled apart inspected and set it up for the same curve. It was worth every cent.

I consider myself pretty handy and knowledgeable in a lot of things on the car and I'm fairly confident I can do a distributor but there is more to just opening it up and welding up the advance slots or dropping in the  plate. I don't have a sun machine to set curve nor do I have boxes of distributor parts laying around to rebuild one with new internals. Plus the time and effort to completely disassemble and clean everything on it. With all that in mind for probably the most critical part to make the engine run your way ahead sending it to any of the experts for them to do.  That's just my 2 cents.


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[1 Wild R/T]

36 total is usually where they are happiest. Limiting advance so you have more initial will make the engine "snappier" and usually idle better. Vacuum puts it into the 40's and 50's sometimes and will increase fuel mileage and burn the fuel better.

Yup.... The key to those timing numbers with vacuum advance is the engine is under light load... Computer controlled timing sometimes pushes timing as far as 60 degrees.... But as soon as the throttle position or vacuum signal changes timing falls out...

If an engine has tight quench it might make more power with less timing but generally 36 degrees is a good starting point....

[Fern]

Thanks for all the replies. I might try and buy the plates from 4 seconds flat and do the recurve. I have a ignition box from them which works well.

[Scooter]

^^^ Lots of good advise up there, agree 34-36 all in mechanical advance is very typical. But unless you built the motor yourself & degree the cam you really cannot trust the timing mark indicators. That and the fact balancers on motors with a few miles on them have been known to slip makes the timing marks more of a guide than anything else. At the end of the day if the motor is running strong and you get no pinging or signs of detonation on the plugs you are probably fine.

[MoparLeo]

Just curious though. I don't know anything about what engine mods have been done or even what type of ignition, distributor etc... you have. Just makes recommendations more real when we know what we are making recommendations for. If nothing is wrong with your distributor, why start to monkey with it ? Do you have a back up in case it doesn't work ? Is this a new engine/car you just got and it had this "problem" or are you making changes and now it won't start with "normal" initial timing ?
How do you drive that you are worried about total advance so much ?
Just like going to the Doctor, the more info you give him the better quality diagnosis you will get. You don't want him to guess at what type or dose of medication he tells you to take if he doesn't have all your info. It might kill you...No ESP here.

[TGGodfrey]

IF you cant weld or don't feel like pulling the distributor a bunch of times, buy the plate from Bob Gould.  So much easier.  Set the plate in the 18* position and reassemble.  Set your timing to 34-36 and go drive it around.  Pull the plugs and set your timing based on the heat mark on the strap.  Every motor is different and setting timing without knowing what the plugs are saying is not really finishing the job. 

When checking your plugs, shut the motor down and coast into the driveway if possible safely.  Don't let the motor idle to much, it can throw off your reads.

[torredcuda]

You can also try different weight springs which affect how soon and quick the timing comes in, as Leo said every engine combo is different so start wit a recommended baseline and adjust from there.

[Fern]

Just curious though. I don't know anything about what engine mods have been done or even what type of ignition, distributor etc... you have. Just makes recommendations more real when we know what we are making recommendations for. If nothing is wrong with your distributor, why start to monkey with it ? Do you have a back up in case it doesn't work ? Is this a new engine/car you just got and it had this "problem" or are you making changes and now it won't start with "normal" initial timing ?
How do you drive that you are worried about total advance so much ?
Just like going to the Doctor, the more info you give him the better quality diagnosis you will get. You don't want him to guess at what type or dose of medication he tells you to take if he doesn't have all your info. It might kill you...No ESP here.

I was just checking what everyone thought about total timing. But your right every motor is different. I have low comp 440 with a Hughes whiplash cam. It did wake up the motor, but since the cam went in, it has always been hard to start. I checked the timing and it was 13* initial and 34* all in, no vacuum advance hooked up. I brought the initial timing up to 18* and it runns much better and starts great, but now im all in at 39*. My question is that ok or too high? Motor dosent ping or detonate and runs good. I dont have much experience with timing so I didnt know if it was ok or if it would cause problems down the line.
The reason the vacuum was disconnected is I didnt realize it was supposed to go up to 47+ with it connected. I might reconnect the vacuum and see how it runs? Again I dont have much experience here.
Thanks

[RUNCHARGER]

I think 39 is too high. It could be detonating lightly and you don't hear it.