what are some good base timing numbers with the vacum advance and without on a practically stock 68 350? the cam is stock and so is the bottom end and it has number 5 heads and headers and an exhaust can i get a base idea

 

There are so many variables with todays fuel and the older engines, I just time it by ear!
Put the gas in it you're going to run, [hopefully premium, with your compression]and drive about 25 miles. Loosen the distributor hold-down bolt 'til you can move the distributor with some pressure.
Advance it a little, and drive it like you stole it! Repeat until it pings, then back it off a little, until it stops.
Tighten the hold-down, adjust the idle, and you're done!
Did this with my suburban, mileage went to 18MPG and it'll run hot if I go from mid-range to regular fuel. [Wife forgot!!]

 

If you still have points make sure your dwell is @ 30 first. Setting timing to 10 - 12 degrees BTC would probably do it @ 1100rpm, then reduce rpm back to 800 for curb idle. Then set your air/fuel mixture. The timing should not be set with the vacuum advance connected.

 

thanks for the response and yes we are running premium and yea this is a father son project my dad likes to do it by ear i was just trying to get a baseline number

 

thanks for the response but it is converted to hei and our idle currently is 1100 but anything lower than that and she likes to die is that normal i mean we havent timed it yet but when you start her she starts on the first revolution and runs pretty well but below 1000 rpms she doesnt like to stay running all the time

 

Check to insure the resitor wire was removed when it was converted. Make sure your choke is not sticking after it warms up. Hook up a tach and adjust your air/ fuel mixture for the highest RPM and then reset your curb idle speed.

 

well we timed it to 12 btc because anything else and she ran so rough but now she runs smooth although the idle feels like there may be a cam we really dont know what was done to the block before we owned it and we have adjusted our air fuel and she is running smooth the funny thing is in park she runs at 1100 and in drive she runs smooth at anywhere from 900-1000 so id say shes running pretty good.

now our trans we got from a guy that swore it was rebuilt in a trade and we think it is shifting fine because if it wasnt we wouldnt be able to hit 55 mph without winding the motor out alot correct? because if it is shifting its shifting so smoothly we can barely feel it

 

Glad to hear your engine is running smooth now. Check for vacuum leaks and see if you can get the idle down below 1000 with the a/c on. Good deal on the trans!!!!

 

68 350 in a 1980 Cutlass Supreme with a turbo 400

Timing -
I started off at 14°, then to 16° back down to 12°.

Team, It feels like something is holding it back until I get to 2500-3000 RPM. Then it takes off, like changing gears.

I want that on takeoff sooner.

Thoughts?

"Rickman48" noted:
Advance it a little, and drive it like you stole it! Repeat until it pings, then back it off a little, until it stops.

This is the direction I plan to go.


"83calais"
rough idle, like a cam, me too! I do not have a cam.

I had rough idle. So I rebuilt the carb, 17058230.

Still, one of my idle screws, passenger side, when I adjust it, does not make a difference to the motor. The drivers side, when turning, does. Example, if I turn it in the motor will die.

I plan to take the carb apart and see where the blockage is.

Thoughts?

 

If you have an advance light, time for 36 total. One of my HEI's needed 12 initial, the other 23 initial to hit 36. The quickest the curves would come in, just over 3000 rpm with the lightest springs.

 

I am trying to follow....


1. Normal operating temperature

2. Plug distributor vacuum (corrected)

3. Set timing to 14° + - at 1000 RPM

4. Advanced timing light, set it to 36°

5. Slowly rev up motor to 2500-3000 RPMs

6. The light should light on “0” on the timing mark

Correct?

 

You don't plug the transmission vacuum, you disconnect and plug the distributor vacuum.

- Eric

 

 

How does it shift under full throttle ? you suerely should Feel it. if it had a shift kit, you would KNOW IT. shifting too smooth.... whats the fluid look like?? should be transparent pink, and toutch of brown, it may be slipping . been sitting that long, maybe sticky valve body.

 

The OP's have probably figured this out over 10 years ago.

 

Or not and the car's spent the decade under a tarp in the backyard, covered in leaves.

 

DOOR #1 DOOR #2 I pick what's behind DOOR #1.

 

I remember 22 years ago when the engine was torn down I had to replace 2 of the rocker arm bridges (aluminum, new are steel), but the NOISE this thing is making, ( and I can FEEL IT with my hand on the carb,)that generally preceeds it shutting down. then it will start right up and run like new ! (stethoscope picks up nothing). it is now has the timeing reset to 12 degrees ( USING" ORIGINAL MARK" ON BALANCER), NO DIFFERENCE WHATSOEVER. I took a NEW 600 Edelbrock off of one of my other projects, installed it, started right up idled beautiful, then started doing the same crap, the noise and Breaking up -- 5 psi fuel at all times, 17 vacuum, 12 degrees before top dead center, idles smooth at 900, .mech adv not sticking, vac adv working properly , used a smoke can to check for vacuum leaks, ...............................................I really do not want to be tearing this thing down , but that "rapping" is scaring me !!

 

I don't believe you realize you are not in the correct thread discussion to be talking about the issues on your vehicle?

 

Optimist.

 

OK, Where should it be ???

 

Probably in the thread you started.

 

OK, had not realized I added on to someone else thread. sorry about that. how do I locate my original post ? Thanks

 

I copied the post (above) verbatim & pasted it into the original thread over one week ago. That post is located here >>>>> Post #102
in your original post located here >>>>> 350 rocket making me crazy

 

Norm makes it easy for you, but in the future you can just use the drop-down menu under your screen name in the upper right-hand corner. Find "My Posts," click on it and it will list all the entries you've posted, starting with the most recent.

 

Thank YOU, WILL TRY THAT.

 

no more noise, but still runs badly