Initial timing question??

-
Brooks James

Brooks James

VET, CPT, Huey Medevac Pilot
FABO Gold Member
Joined
Dec 12, 2020
Messages
5,537
Reaction score
3,712
Location
Fruitland Park Fl
I have an mp distributor I bought from another member and all I know about it is that it is set fo 36 degrees all in by 2600 rpm
How do I discover how much initial advance I have? Do I need a dial back timing light?
 
Initial timing is determined by your timing light! Total is determined the same way! If you have tape or marks on your balancer it is easy to see. Distributors have no set values inherent so to say. They have limits if done as such.
 
For me initial is at current idle! I want full advance as early as possible with total not exceeding 34/38. I do not use vacuum advance! This works for me but not the whole story!
 
Initial timing is where you set the timing not started, and at or near top dead center right before firing happens in the #1 cylinder. It is usually set by identifying when the piston is approaching TDC on #1, and is usually set at 12 degrees before TDC. When you start the car, the timing light should show -12 on the timing tab, and any acceleration will move the mark even further advanced until it stops moving. When it stops, your advance is “all in”, and with a tach or dwell meter, you can easily find out what RPM that is. And with an advance timing light, you can find out what degree that is by dialing it until the flash goes back to zero, and reading on the light at what degree that happened.
 
Damn, can someone make a mopar ignition timing set for dummies video and tag me on it. Something that takes into consideration that some of us are like new borns when talking about certain subjects. Haha

I feel like I don’t have this-
 
So because my total advance at 36 is where I want to start my concern would be not having to much initial making it hard to crank??
 
BIG-B-Barracuda said:
Damn, can someone make a mopar ignition timing set for dummies video and tag me on it. Something that takes into consideration that some of us are like new borns when talking about certain subjects. Haha

I feel like I don’t have this-
Click to expand...
Basic Concepts and Terms.
Start Here! Post 30 Performance timing

Step by Step
post 48 Performance timing

Same thing phrased another way.
Step by step total timing instructions

Some hi-po factory timing specs shown here
1968 340 timing
Seeing these timing curves may help some visualize how initial, mechanical advance, and maximum mechanical relate.
 
Last edited:
Why do folks make this so hard?

Give it all the advance your particular combo can handle without bucking on the starter to fire and idle good! Now you have initial!

Every combo needs something a bit different!

Check it with a light and tape and such if needed and record.

Next get a total with your light and tape for at whatever RPM it takes to get it there. Record it!

lastly limit your dizzy for such to 34/38. Through the best means!

And there are a lot options out there to do so depending on your dizzy unit.
 
Last edited:
That said for the majority of performance BB and SB from the 90’s back!

I have my damper marked for 36 total. With my combo, about 18/19 intitial.
 
Last edited:
Because that's too much initial for producing good power at idle - with exception of some high compression engines with aftermarket cams. Sometimes things just work out like that.
 
Initial timing is where you set it by the distributor being turned clockwise or counter clockwise while seeing the mark on the balancer to verify base timing

mechanical timing is what’s in the distributor this does not included the v can.

so say you have 14initial base timing and 18 in the distributor that’s a total of 32 degrees.

Without a timing light an easy way is to rotate the distributor when you hear the engine vacuum rising engines idle, keep going until she starts to lose vaccum and the idle lowers. Then go ahead drive the car once your hear it ping retarded the timing until you stop hearing it. That’s pretty much were you wanna be.

you can master it by different springs in the distributor taking out more timing in the distributor etc but it sounds like your not that far off.
 
1969383S said:
Why do folks make this so hard?

Give it all the advance your particular combo can handle without bucking on the starter to fire and idle good! Now you have initial!

Every combo needs something a bit different!

Check it with a light and tape and such if needed and record.

Next get a total with your light and tape for at whatever RPM it takes to get it there. Record it!

lastly limit your dizzy for such to 34/38.
Click to expand...

Yup. Guys like us were welding up and filing out distributor slots in auto shop in high school. Then there are some guys on here who are self professed geniuses and give all their advice straight out of manuals and using computer formulas.

Me? I'd much rather go with the concrete, hands on experience like you describe. Setting timing until you get spark knock, or until the starter lugs....whichever comes first and then backing off about 2* is a great short cut without a light method.....and it works! Plus, fact is, on most street builds using stock compression, you cannot have too much timing to hurt anything. I've run them at 20 plus or minus initial with 41-43 total with 8:1 static and camshafts in the 230 @ .050 range. You almost cannot GET that to spark knock. Sometimes old school is the quickest fastest method to get what you need......but some people on here just have to show the whole damned world how smart they think they are.
 
Mattax said:
Because that's too much initial for producing good power at idle - with exception of some high compression engines with aftermarket cams. Sometimes things just work out like that.
Click to expand...

You are exactly correct! Every combo is different. My combo needs and wants this!

The procedure is a the same though! It works 95% of the time and oh so simple!
 
Last edited:
We could all spend hours on a Dyno and only learn what our car wants!

There is no total answer for each but basic theory to follow!
 
Thanks for all the replies!!
I “get” it now. I’ll be needing a timing light and a degree tape.!I’m thinking I might need to change the total advance though as I have read that magnums like ke 33-34 and it’s set up now for 36.
 
Brooks James said:
Thanks for all the replies!!
I “get” it now. I’ll be needing a timing light and a degree tape.!I’m thinking I might need to change the total advance though as I have read that magnums like ke 33-34 and it’s set up now for 36.
Click to expand...

Do not miss the big Picture!

You have no idea what your total is until you find what your motor likes for initial by adjusting dizzy position! Only then can you find the total at RPM! At that point you can limit or extend the total advance of your dizzy to achieve the 33-34 you seem to want! Varying the springs in the dizzy will determine how fast you get to the total.
 
Last edited:
1969383S said:
We could all spend hours on a Dyno and only learn what our car wants!

There is no total answer for each but basic theory to follow!
Click to expand...

Our auto shop instructor, who was retirement age our first year with him always said "give one all the advance it can stand, without spark knock or lugging the starter". Direct quote. I've found that works very well and 9 time out of ten it ends up right where all the calculations with a timing light and vacuum gauge will tell you. Other than "possibly" limiting total timing, that's really all you need to do. Now of course, racing for points or money, you're gonna wanna pull the tuning tools out, but you're still gonna be close the old way.
 
RustyRatRod said:
Our auto shop instructor, who was retirement age our first year with him always said "give one all the advance it can stand, without spark knock or lugging the starter". Direct quote. I've found that works very well and 9 time out of ten it ends up right where all the calculations with a timing light and vacuum gauge will tell you. Other than "possibly" limiting total timing, that's really all you need to do. Now of course, racing for points or money, you're gonna wanna pull the tuning tools out, but you're still gonna be close the old way.
Click to expand...


I should have put "Our" car in quotes! Every motor is just a tad different yes? The only true way is dyno each, Yes?
 
1969383S said:
I should have put "Our" car in quotes! Every motor is just a tad different yes? The only true way is dyno each, Yes?
Click to expand...

Absolutely, but who has a dyno in their back pocket all the time? lol
 
Brooks James said:
Thanks for all the replies!!
I “get” it now. I’ll be needing a timing light and a degree tape.!I’m thinking I might need to change the total advance though as I have read that magnums like ke 33-34 and it’s set up now for 36.
Click to expand...
Since its a MP distributor, then yes you can can use the DC/MP guidelines for a magnum as a starting point.
It's about things that change the time for combustion to build pressure.
Two points of caution.
a. There were two versions of the MP distributor with vacuum advances. They have different advance mechanism and therefore different curves.
You can identify which version it is by looking. Photos on the left show the Mallory made version. Digital Mavica image viewer
b. As a previously used distributor there's no guarentee its still the original settings.

Third, 33-34* at ______ rpm is critical to know. Pick an rpm or two and make it your reference point. DC/MP used 2600-2800 rpm on their older guidelines. I usually make a quick check at a higher rpm too.
Same goes if working at idle. Setting initial at 800 rpm is usually not the same as setting timing at 650 rpm. So always note the rpm a timing measurement is made.
 
You must log in or register to reply here.
-

Back
Top