NOOB with a TIMING light gun

-
BIG-B-Barracuda

BIG-B-Barracuda

Well-Known Member
Joined
Dec 25, 2011
Messages
1,171
Reaction score
87
Location
CALIFORNIA
just finished timing my car, here is what i did...

1968 plymouth barracuda - stock 440 mugnum off of a 1973 ( i think 90% sure) dodge charger. no points, electric ignition stock distributor.

went to SEARS bought a 60 dollar gun. (pretty good gun actually)
got home let it cool down, loosened the distributor.
disconnected the vacuum advance and plugged them both.
set the timing at 16-17. hooked the vacuum back on and checked timing at 2500/3000 timing was at around 36-37....total
tuned and messed with the fuel to air ratio a bit.... runs way better..! but not sure if correct way to do things

:burnout:
something could be wrong since i havent done this before...

someone tell me if i did this right, my first time. haha

:blob:
 
You need to check total with the vacuum can disconnected. Total on a big block should be around 34* - 36* or so with the vacuum can disconnected.
 
if i understand correctly,

with the vacuum still disconnected and plugged and both ends
idle car at 2500/3000 and set total timing at 34/36?

after setting the initial how do you set the total, wont it change the initial timing?

again i am sorry but i am trying to understand this from a step by step point of view since it is my first time.

like a new born with a ...... calculator?
 
Here is a video about timing not about brand X, pretty good info here, probably the most complete video regarding timing.

[ame]https://youtu.be/e-k2fdTZP7o[/ame]
 
Full mechanical is what you need to be setting it at. 2500 RPM. and 34-36 degrees. lock it there with the nut, and then idle it down. You more "take note" of your idle base timing opposed to trying to fine tune by it. They kind of idle where they idle unless something is off and making it abnormally high (say over 14-15?)
only then...do you hook the vac advance back up.
 
The vacuum can is disregarded when setting timing. Whatever it adds when vacuum is applied is NOT a part of total timing. Total timing by definition is initial plus mechanical. Period.
 
When you are setting total, you need to make sure it doesn't KEEP advancing. I NEVER assume "it's all in." Get it where you "think" it is at 25-3000, and then while watching the marks, "blip" the throttle to make sure it doesn't move.
 
Factory distributor springs usually consist of one fairly light spring and one heavy spring with a slot that pretty much acts as a stop until the higher RPM. Unless your distributor has been worked on you should put in two light springs and then restrict the slots as needed to achieve the "mechanical" advance of all in at 2500-3000. Then check it at cruise RPM with the vacuum connected to see what your "total" timing is. I will let the conflict over wording settle itself....
 
okay understood,

i should start the process off by disconnecting vacuum and idling to 2500/3000 and setting mechanical timing at 34-36 and then let it idle back down connect the vacuum back on and check the timing there? should be at 14-16?
 
mguner said:
Factory distributor springs usually consist of one fairly light spring and one heavy spring with a slot that pretty much acts as a stop until the higher RPM. Unless your distributor has been worked on you should put in two light springs and then restrict the slots as needed to achieve the "mechanical" advance of all in at 2500-3000. Then check it at cruise RPM with the vacuum connected to see what your "total" timing is. I will let the conflict over wording settle itself....
Click to expand...

thank you. :cheers:
 
I couldn't figure her out guys.
I got home let her cool down and disconnected the vacuum advance plugged them idled her at 2500/3000 and timed her at 35-36 tighten her down then hooked the vacuum back on and something didn't seem right was idling high.

I mean total is se at 36 now and followed the video but something just feels off.
 
In general, the more spark advance the better (mileage & power), until you get pinging. Modern cars (~1995+) use a knock sensor and keep advancing the spark until they sense pinging, then back off 2 deg and advance again. At least, the Holley Commander 950 works that way. That lets them work optimally with most any gas.
 
Sounds like the port you put it on is the manifold vacuum? If not your throttle plates are so far open the ported slot is exposed as well as the fuel transfer slots..... If it is manifold vacuum and you like the way it runs other wise just back down the idle stop screw and readjust your idle mixture settings.
 
the left is vacuum and the right is manifold correct?

okay understood ill try once more when i get off of work and get home.

thanks for everything !
 
Once the total advance has been set, you may need to adjust the idle screw up or down slightly.

Advancing the timing would probably result in a higher idle.
 
Not sure I read what carb you have but.... "Ported or timed" is on the passenger or right hand side.
vbpgimage.php
 
okay ill go home and time it at 35 and mess with the air to fuel and idle screw...

one more thing. i think i missed a step.

is it necessary to have the car at TDC before doing the timing?

if so how do i get it to TDC ? just turn the ignition (turn over) till i get it close enough?

i think thats what i did wrong...
 
Does your gun have a degree knob on it? If you want to check the accuracy of your timing marks you can do that. That would also require a TDC indicator tool or some pretty good dead reckoning by watching the valve train or having a finger in the spark plug hole... etc. If you trust your marks there is no need to mess with finding TDC. Some inductive pickup timing lights like my old Snap-On are sensitive to the direction the clamp goes around the #1 wire. If you don't get a clean signal try flipping it.
 
That is a great light, you should be good to go by just hooking the timing light up properly with the pickup on the #1 plug wire,

slightly loosen the bolt on the distributor hold down.
disconnect and plug the vacuum advance line at the distributor,
start the engine and let it warm up,
then bring the rpm's up to 3000 or so,

Point the timing light at the timing mark, and turn the dial clockwise until the timing mark on the harmonic balancer is aligned with TDC on the waterpump housing.

If you are between 32 and 34 you are done.

reduce the rpm's to their normal speed for idle, make any necessary SMALL adjustments to the idle speed and mixture screws.

Check the timing again at idle by using the dial to once again align the timing marks to determine the initial setting.

hook the vacuum advance back up, if the idle changes you may have a vacuum leak at the diaphragm in the advance canister.

Subtract the initial timing setting from the number you set the engine at at the 3000 rpm, this was you will be able to determine the total mechanical advance of your distributor.

shut down the engine and let the engine cool if necessary and tighten the distributor hold down.

restart the engine, double check that you did not move it off the initial timing setting and you should be good to go.

Test drive it, if there is any changes to be made from there they should be 1 or 2 degrees either way, which really should not be that significant.

Good Luck
 

Attachments

  • yoda-lightsaber.jpg
    28.2 KB · Views: 286
Ok. This has gotten pretty stupid. I am out.
 
Why are you out RRR?
The information is good and the picture is funny.
Noob is trying to learn.
I know it all seems like trivial information to you but remember Big is trying...
In my book, that is way better then those that give a crap, throw gas at it and wonder what the 'Red Light on the Dash' means.
I have been / and sometimes still am in his shoes and the people with the good information like you are the ones that get me / them through until the 'Light' comes on and they / I get it.
Please stick with him / me. That way, I can pass that stuff down to my boys and it will continue that way.
Thanks
 
Everybody seems to be caught up telling him to set total timing. That's not the correct way. Set initial timing FIRST, then look at total. If total needs adjusting, then do it. Usually on stock distributors, you set initial around 18-20 or so and limit total to 34-36. Nobody's said any of that here.
 
Or the pick a random RPM number to set total.

If the distributor is still advancing at 4K and you set it at 3K, is the total you set really the total?

You run RPM up until it stops advancing to set total... PERIOD!!!

This nugget is really good!
When you are setting total, you need to make sure it doesn't KEEP advancing. I NEVER assume "it's all in." Get it where you "think" it is at 25-3000, and then while watching the marks, "blip" the throttle to make sure it doesn't move.
Click to expand...
 
RustyRatRod said:
Everybody seems to be caught up telling him to set total timing. That's not the correct way. Set initial timing FIRST, then look at total. If total needs adjusting, then do it. Usually on stock distributors, you set initial around 18-20 or so and limit total to 34-36. Nobody's said any of that here.
Click to expand...

What he said ^^^^^
Also read this , it might shed some light on things http://www.mopar1.us/engine2.html
 
You must log in or register to reply here.
-

Back
Top