I've never set my timing before. How do I do it? Should I buy a timing light?

 

DaddyO ........... STEP AWAY FROM THE CAR :nono:

 

Give him a break! :)

You plug posi to posi on the alt, ground to a good ground source. The pickup goes to the #1 wire. Use an adjustable timing light, fire at the harmonic balancer. You should get a strobe somewhere on the markings on the light.

It's pretty straightforward.

-Steve

 

Yes, timing is a VERY important part of engine performance, therefore, you should own (or borrow) a decent timing light.

1) Clean your harmonic balancer so you can see the mark (good idea to use some "white out" on it to enhance.
2) Also, clean the timing tab and become familiar w/ where 12 degrees Before Top Dead Center (BTC) is (the most common initial timing point for Small Block Chevy's)
3) Connect the inductive pickup (clip) on #1 (most-forward on driver's side) spark plug wire (careful around headers, if equipped). Connect the pos (+) clip to the bat (+) post on alternator (Heavy gauge red wire will also be connected at this point) Connect neg (-) to good ground (Master cyclinder is usually a good point)
4) Disconnect the vacuum line that runs from your carb to the vacuum advance unit on your distributor and plug it (a pencil or golf tee works well)
5) Loosen (a turn or two) the distributor hold-down bolt (9/16" wrench)
6) Mark the distributor w/ a reference point, so you can go back in case it gets worse and you can't get it to run correctly
7) Start car and let warm-up to operating temp
8) Set idle to car specs (see sticker under hood) probably in the 700-800 RPM range.
9) Aim timing gun at timing tab and see if timing mark is at the 12 degree mark. Turn distributor counter-clockwise to advance, clockwise to retard.
10) Tighten dist hold-down bolt and reconnect vacuum line.

I've recently installed an LT1, which does not allow for timing adjustments, so I mayhave forgotten something...please feel-free to correct/clarify anything I've stated.

:cheers:

Dr.

 

OK, 1 more dumb question....do I adjust the distributor while the car is running?

 

Yes, with the car running, twist the distributor to advance or retard the timing.
If you are using an adjustable timing light, such as the Sears $60 one, set it to 0 and you should see your timing mark on the timing tab. As said before clean off the tab and bump the starter a couple times to get the timing mark rotate around so you can see it. It should be a straight cut across the balancer. Clean it up, fill the notch with white out or chalk (the liquid white out pen works great). With a non adjustable timing light your look at the number where the mark hits the tab. Works great but most tabs only go to 12, My car I have set to 16 btdc. With the adjustable timing light if you move the **** to 16 and the timing mark lines up with 0 on the tab, then your timing is set to 16. One other tool makes the job easier. You should pick up a 9/16 distrbutor wrench, about $6 at most auto parts stores. It is a box wrench with a 90 deg bend. Fits under the distributor to get to the nut. I had to rebend the wrench slightly to get around the vac. advance. One last thing, make sure you remove the rubber vac line to the advance and plug it before you check or adjust the timing. A golf Tee work great for this.

 

Yes, at idle speed. Don't be afriad to ask questions,even basic ones. the more you ask the more you'll be able to do on your own. if you have a 71 then you'll be able to do just about anything to it with help from this forum and tools.
Good luck
PS Sears Craftsman adjustable light is very good and they're having a 10% sale for craftsman club members till 10/3/03.
Gary

 

One point of safety here, DO NOT grab the top of the distributor cap when you try to rotate the distributor unless you like that tingly feely you get as voltage surges through your body. All it takes is one bad plug wire to give you that wide eye, hair standing straight up on end look! :lol: :crazy: Be sure to either grab the distributor base or the vacumn advance canister to move the distributor. You won't need to rotate the distributor much, maybe a 1/2" in either direction.

 

Try a little more advance than stock.
Don't be concerned w/ "dumb" questions, you gotta start somewhere & then

Suggest Increase Power.

:cool:

 

Thanks to everyone for the help!

 

Heres another safety tip. BE CAREFUL!!! Timing lights have wires that will get sucked into the belts and fan if you are not careful. Also watch out for hot exhaust maniflolds as stated above. Anytime you are working on a running engine just be aware of rotating parts and keep the kids away from the inside and outside of the car. You don't want jr. in the car and find the shift lever while its running :eek: :eek:

 

Good advice above, and here is my advice as a clutz who hasn't been doing this for the past 40 years: Be very careful loosening the distributor hold down bolts. You want the distributor to be loose enuf to turn, but not so loose that it turns freely. (Good advice above to mark the original position of the distributor!!) It can be a little tricky as a one man job because you are leaning forward and holding the timing light with one hand (Watch out for the fan and belts!!!) and turning the distributor very gently with the other hand. Then when the timing is where you want it, you have to tighten it down without twisting it, which would change the timing.. You will be able to hear the difference in your engine idle speed and "quality" as you turn the distributor and change the timing. Fun stuff! :) MJ

Also, the instructions that come with the timing light will tell you to attach it to your car battery..... Well, they don't realize our batterys are far away behind the drivers seat. You can use a jumper cable to reach the battery (like I used to do when I followed those instructions to the letter) or much easier just hook it on to the alternator which is much closer.


[Modified by MNJack, 9:07 AM 9/27/2003]

 

DaddyO,
These are all excellent suggestions to learn how to tune the vette. Here are two more:
1. Join the local Corvette club and ask help in learning about engines and tuning.
2. Go to the local library and scour the books on engine tuning, building etc and spend time reading.

Good luck and if you are comfortable doing something = don't until you are.

 

Hey Guys,

I want to thank all of you as well for these replies. I am also learning how to set timing. I have been able to do alot automotively over the years but now I MUST learn how to adjust carburetors and set timing.

I need to verify one thing said earlier in this post:

Are you ADVANCING the timing when you turn the distributor COUNTER CLOCKWISE???

Counterclockwise????

Is this right??

Thanks!!

Bob

 

There are those who stand on the outside and arrogantly cast doubt and there are those who venture into unknown territory and discover their true potential. Good for you DaddyO!

 

Another thing you should purchase is the 1971 Chassis Service Manual. They're on ebay right now, $9 used, $25 for a new copy. It provides procedures for maintenance and adjustments (timing, dwell, idle etc) as well as all specs for your car.
Good Luck. :chevy

 

Yes that is correct. Counter-clockwise to advance.

Pete


[Modified by Pete79L82, 11:44 AM 9/27/2003]

 

Loosen the nut at the base of the distributor and as you hold the timing light flashing at the harmonic balancer and watch the marks on the indicator and the balancer till you match up the specs and the mark. Watch your hands and keep the light away from the fan and the belts, shut off the engin and tighten the nut a little bit. don't overtighten the nut and your set.

 

I know this has already been clarified, but just to add: Since the rotor beneath the distributor cap spins CLOCKWISE, to get to a terminal post sooner (ADVANCING), you would turn the cap COUNTER-CLOCKWISE.

Think of the rotor as a hand of a clock...if you want to advance time, you would turn the clock COUNTER-CLOCKWISE (Assuming the hand of the clock is FIXED, as is the rotor, and could not be turned manually)

Hope this doesn't confuse it any... :confused:

Dr. :cheers:


[Modified by DR'76, 8:49 PM 9/27/2003]

 

Yes, it does confuse the topic. If you are going to "advance" the time, you move the Big Hand ahead of where it is now. Hence, clockwise. :crazy: