Shawn Mac
Member
My problem is the timing for a stock 1976 360 with 4 barrel. Is btdc above the zero line or below? How many degrees does each notch mean? All answers will help. Thank You
New to mopars and with stupid questions!
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Above or below is ambiguous at best; advance is ccw of the zero,which if the index is on the passenger side of the engine,I suppose could be "below".
Each division is 2 degrees
There are long hash marks at the 10 degree points, and the in-betweeners are shorter.
Welcome to FABO
Be careful when setting the timing using base or idle-timing.
With a stock D (Distributor) you generally cannot arbitrarily add much timing at the bottom without having too much at higher rpms, which can damage the engine.
The whole point of having adjustable timing in the D is to have the proper advance after about 3600 rpm. But if you set it there, starting becomes difficult, and the engine may suffer detonation at lower rpms. So some form of advance reduction for idle, was invented to satisfy the engine's requirements at both ends, and the mechanical advance D was born.
You can play around with it all you want, so long as you do not exceed ~36* at ~3600, AND so long as she doesn't detonate under load. Detonation breaks parts and must be avoided at ALL costs
More is not always better, unless maybe you had a Chebby,lol.
36*@3600 is not written in stone, but is a generically safe target. Every engine, and every combo, seems to have it's own personality. So some might allow timing to be perhaps 2* either way from 36* and or may allow the timing a little earlier. Just don't get carried away
Each division is 2 degrees
There are long hash marks at the 10 degree points, and the in-betweeners are shorter.
Welcome to FABO
Be careful when setting the timing using base or idle-timing.
With a stock D (Distributor) you generally cannot arbitrarily add much timing at the bottom without having too much at higher rpms, which can damage the engine.
The whole point of having adjustable timing in the D is to have the proper advance after about 3600 rpm. But if you set it there, starting becomes difficult, and the engine may suffer detonation at lower rpms. So some form of advance reduction for idle, was invented to satisfy the engine's requirements at both ends, and the mechanical advance D was born.
You can play around with it all you want, so long as you do not exceed ~36* at ~3600, AND so long as she doesn't detonate under load. Detonation breaks parts and must be avoided at ALL costs
More is not always better, unless maybe you had a Chebby,lol.
36*@3600 is not written in stone, but is a generically safe target. Every engine, and every combo, seems to have it's own personality. So some might allow timing to be perhaps 2* either way from 36* and or may allow the timing a little earlier. Just don't get carried away
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I always thought each notch was for out running Chevy's!
Welcome to FABO
Welcome to FABO
Shawn Mac
Member
Thank you for the info. It has a new HEI dizzy. So I'm looking to be around the third line on top of the zero at idle?
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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MAYBE
What you really want to do, is, with the vacuum advance defeated, rev it up while watching the advance march , until the advance stops moving, and is "all-in";then make sure it's not more than 36*, (34* is safer for a newbe). Adjust the timing to 34/36 at that "all-in" rpm, and return the engine to idle. Now whatever the idle timing is is your NEW base-timing.
Now if you want to experiment with more base-timing, you will first have to reduce the centrifugal timing inside the D, so as not to exceed that All-in timing of 34/36@~3600rpm
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Or 52*’s max with the vacuum advance hooked up.
Shawn Mac
Member
Watching the advance. Explain please.
Well, you'll want a timing light hooked up, when you rotate the distributor you will see the timing mark on the balance move in relation to the stationary marks on the timing cover.
Make sense?
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Watching the timing is done by aiming your timing lite at the marks,pulling the trigger and with your free hand reving up the engine. The timing marks will advance steadily until they disappear well past 10*. You will need either a "dial-back" lite to read where the advance ends up; or you will need to continue the calibration marks on the balancer, or apply a timing tape to the balancer, to be able to use a conventional lite. Any method is good, and I prefer the timing tape.
Shawn Mac
Member
Make sense? Yes, thank you. So, say at 1000 rpm I should turn dizzy to 34 degrees above the zero mark? I do not want to sound stupid, But I AM! I have a new Innova 5568 timing light coming Monday if I can figure out how to use it.
Do you have a timing light? If so, disconnect the vacuum hose from the distributor, loosen the hold down bolt just enough so you can turn the distributor with a little force. Then start the engine, as you advance the distributor the idle will speed up. Your base initial timing is the timing at idle (at normal rpm) and the advance is the timing at 3500+ rpm. With a OEM distributor it is usually about 10 degrees initial and 34 degrees advance.
A performance timing would be usually around 16 initial and 34-36 advance. With a stock distributor 16 degrees is not always possible. I would suggest one of these.... How to limit mechanical advance in a mopar distributor, tuning for street, strip or all out racing, cure that rich stinky idle, win races
You can buy timing tapes cheap off amazon or at an auto parts store. They come in a sheet for different size harmonic balancers. The 7.25 one is missing, so that must be the size I used on my 75 360 engine that is in my car. You can measure yours to find the diameter. They don’t stay on very well, so clean the surface with acetone or lacquer thinner or something like that.
I think there is a thread on here about how to get them to stick.
I think there is a thread on here about how to get them to stick.
I have no idea what the mechanical advancement is on a HEI distributor, but most factory distributors have anywhere from 18-24* mechanical advance.
Here is what I'd do and why:
Here is what I'd do and why:
- Set the timing to 10* before top dead center. the ZERO on the timing chain cover is top dead center. Assuming your car has the original timing cover, that would be the 10 "above" as you described it. the engine will pick up rpm's as you go above TDC.
- the reason why I say to do it like this, is you'll be all confused trying to find 34* full advancement because your timing mark will disappear on you, as your timing chain cover is only meant to set timing at idle. This will net you probably 30-34* full advancement, depending on the distributor. This won't be perfect timing, but the car should run and drive good at this timing (assuming it has stock camshaft).
- then, visit the "hillbilly timing tape" in the "search" right here on FABO, or buy some timing tape. You'll be able to dial it in to what the car want's and know where your at full advanced.
- IF it's not been touched, it's a lower compression motor. Sometimes they like 38-40* full advanced.
Most any and all timing marks are before top dead center, and if there is any on the ATDC side, there will be very few. A pic of your balancer in relation to the timing tab would do wonders here!
67Dart273
Well-Known Member
NO!!! 1000 RPM may not be enough to engage the mechanical advance fully ESPECIALLY the later model the distributor, because they have a "long slow" advance curve. And on that note you should consider checking/ recurving the distributor. In other words, "wind" the engine up to high RPM at least once to make sure it does not OVER advance
I realize you have an aftermarket distributor here, but nevertheless you want to be sure it does not over advance at higher RPM
On a side note, "dizzy" is a silly word. In your defense, I realize it has "come into some use."
As a clarification, you can use an adjustable timing light, or a timing tape, you don’t need both. Some find that the timing tape is easier to understand.
Shawn Mac
Member
Shawn Mac
Member
In regards to the pics I posted, any ideas which line to match up with balancer at idle? Thanks
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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So that looks like a 69 and older 318/340 cover, not a 360 cover, Now, the CCW advance marks are "UP"! And there was never a 360 balancer made to work with that cover!
And this cover seems to have long hashmarks at 4/6*BTDC; no matter. You will need the Dial-back lite OR, to mark the balancer. There is no other way..... for you.
EDIT
But if your engine is really a stock 360 and if those marks on the cover are on the DRIVER's side then STOP!! The stock 360 balancer and the 69 and older 318/340 cover in stock condition are NOT COMPATIBLE! One or the other will need to be changed out, or to be modified, from stock.
If you try to use the stock 360 balancer with the 318/340 cover, the TDC index will be 90 degrees off, and it will not start nor run
A stock 360 engine will need to have a stock-type 360-balancer installed. The stock 360 was engineered to have the timing synchronized on the passenger side, so the stock 360 will have the TDC indicator on the passenger side where the older 318/340 covers have nothing to sync to!. So You would be in trouble...... unless someone has made a new mark on the stock 360balancer,on the driver's side. In which case you will have to prove that it was put in the correct spot.
Second EDIT ; As 318willrun notes I got this backwards , so entire post does not apply , ignore it with apologies.
And this cover seems to have long hashmarks at 4/6*BTDC; no matter. You will need the Dial-back lite OR, to mark the balancer. There is no other way..... for you.
EDIT
But if your engine is really a stock 360 and if those marks on the cover are on the DRIVER's side then STOP!! The stock 360 balancer and the 69 and older 318/340 cover in stock condition are NOT COMPATIBLE! One or the other will need to be changed out, or to be modified, from stock.
If you try to use the stock 360 balancer with the 318/340 cover, the TDC index will be 90 degrees off, and it will not start nor run
A stock 360 engine will need to have a stock-type 360-balancer installed. The stock 360 was engineered to have the timing synchronized on the passenger side, so the stock 360 will have the TDC indicator on the passenger side where the older 318/340 covers have nothing to sync to!. So You would be in trouble...... unless someone has made a new mark on the stock 360balancer,on the driver's side. In which case you will have to prove that it was put in the correct spot.
Second EDIT ; As 318willrun notes I got this backwards , so entire post does not apply , ignore it with apologies.
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Shawn Mac
Member
Thanks! There is a long notch on the balancer. Just not in the pics.
Shawn Mac
Member
Here is another pic that I just took showing the line on the balancer that is filled with soap stone. Also, I did not notice til blowing up this pic that there are other smaller deg. marks on the balancer. My eyes are not what they used to be.
A/J, this is just wrong. That is the correct timing cover.
Shawn Mac You have the right idea. Advancing, or before top dead center, is up in the pictures. If you'd like, I'll make a video and post how to set ignition timing.
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Shawn Mac
Member
That would be GREAT! Would that be a youtube thing or would you post it here
I will upload it on youtube, and post it here. Got a couple things to do, then I should have it uploaded and posted right here on your thread in a couple of hours.
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