Thanks to the guys for the info on setting the timing! I hooked up a tach and set the timing to 32 deg at 3400 rpm. needless to say the car revs up alot better and smoother:hurray: But i still have an issue with the carb i'm guessing. I still cannot get the car to idle well at like 800 rpm as i would like. The lowest I can release the throttle is to about 1300 rpm but even it gets real lopey and the engine shakes excessively. I have no vacuum leaks present. There is only like the 3places where it could leak from and i already plugged em just to be sure.
So the jist of it all is that I cant get it to idle normally
It runs rough at the lower rpm if not shuts off.
before it shuts off on its own, it will let out a small backfire thru the carb.:(

heres some info on the motor

350 out a 81 Z28 camaro that ran good before i pulled it.
I junked the carb, intake, timing chain and hei dist.

I installed new headgaskets along with all the other gaskets
I installed a new timing chain
I installed a new edelbrock peformer intake
I installed a new holley 4160 4bbl 600 cfm vacuum sec elec choke
I have not tampered with the carb besides the idle screws
I installed a new hei dist from ebay for $65 bucks
The cam is stock, The cam is stock:yes:
The fuel being used is 87 oct that it is being drawn from fuel can just to make it a point that i'm using fresh clean fuel. it is also being run thru a new fram filter.
Timing at 32 @3400 rpm with vac advance disconnected
timing chain was installed dead on, not advanced or retarded

With a vac guage connected, the needle sweeps back and forth wildy which is on par with it running rough. I'll be honest, when I did the valve adjustment. I got lost more than a few times and i have a feeling some of the valves might be a bit too tight. Anyone have some good instructions on adjusting valves? anyone have info on adjusting tips for the holley 4160?(ie adjusting or checking float level etc) or any other guidance or info? Thanks guys :hurray:
http://i78.photobucket.com/albums/j99/daminature/nowrunning003.jpg
http://i78.photobucket.com/albums/j99/daminature/montecARPICS011.jpg

there are a bunch of different ways to adjust the valves, the two ways that work best for me are, do it while it's running (stock cams) or on aftermarket cams I warm it up and roll the motor over and wait for an exhaust to open all the way, then adjust the intake, same thing wait for an intake to open and then adjust the exhaust, make sure to keep track though, this method take awhile but it works.

The first thing I would do is put the light back on it and rev it well past 3400 to see where total timing actually comes in. Many stock distributors don't reach total until near or past 5K rpm and many aftermarket distributors come out of the box with 4k+ curves. Once that you've established where the peak occurs, set total to 36º. For adjusting hydraulics, (assuming stamped steel rockers) I use clips (available at any speed shop) over the rockers and set the idle as low as possible. The lower idle reduces the amount of oil spurting and also makes it easier to hear the individual valves. Back off the adjusting nut until it clacks, turn it in until it just stops, and then give it another 1/2 turn. The idle might drop when you first tighten it but should should come back in a few seconds. If not, loosen it until it does.

you have a blue sharpe stuck in the choke:D

you have a blue sharpe stuck in the choke:D

removed the blue sharpe....nope didnt do a thing:D

The first thing I would do is put the light back on it and rev it well past 3400 to see where total timing actually comes in. Many stock distributors don't reach total until near or past 5K rpm and many aftermarket distributors come out of the box with 4k+ curves. Once that you've established where the peak occurs, set total to 36º. For adjusting hydraulics, (assuming stamped steel rockers) I use clips (available at any speed shop) over the rockers and set the idle as low as possible. The lower idle reduces the amount of oil spurting and also makes it easier to hear the individual valves. Back off the adjusting nut until it clacks, turn it in until it just stops, and then give it another 1/2 turn. The idle might drop when you first tighten it but should should come back in a few seconds. If not, loosen it until it does.

thanks i'll give this a shot. You know whats a damn shame is that i do great valve adjustments on diesel engines and the S54 BMW M3 motor and I cant do the damn valve adjustment on a chevy 350:noway::D

FYI,dont just set timing for total because that often leaves the initial/base timing retarded resulting in power loos,wasted fuel,and poor throttle resp.

Most sbc/bbc street perf motor's like approx 36-38 total all in by approx 2800-3k rpm so the 32 deg total your running is retarded by 4-6 deg which is substantial.

That's not to mention if for example the dist has 24 deg mech and your total maxes out at 32 deg then 32 deg total - 24 deg mech in dist = a retartded 8 deg initilal when the motor need 18 deg initial with a perf cam,thats running the initial 10 deg retarded which is bad killing your motor power/trq,est off idle and at low speed.

If your running any kind of aftermarket perf cam that 8 deg inital your running if the dist actually has approx 24 deg mech adv is extreemly retartded (10 deg retarded for initial timing) which will cause idle issues and idle mix adj issues. Thats because the retarded initial timing makes you have to inc/adj the ilde speed screw so far to obtain a decent idle that the prim throttle blades are puched past/out of the idle circut rendering the idle mix scews inoperative/inactive.

So if running a perf cam set the initial timing to 18 deg,make sure idle is low like 600-650 rpm when setting initiaql to ensure the mech adv doesnt upset initial timing adj. Also unhook/plug vac adv when setting/checking initial & total timing.

For street motor also make sure your running a vac adv hooke to full intake vacuum all the time thats fully activated at idle for a better idle due to additonal timing and shraper throttle resp when comming off idle & when at part throttle cruise.

You must get the ign timing adj correctly before trying to go after carb issues becasue many times its the timing being too retartded like in your case thats causing what seem to bew car issues when in fact its retarded timing causing the problem.

After setting initial to 18 make sure to rev motor to 3k and above that to 4500-5k to see if the total goes past 36-38. If its 36-38 2800-3k rpm and stay there above thsat rmp your good to go. But if the total is over 38 at 3k rm and above you need to have the mech adv in the dist recurved for 18 deg max in by 2800-3k rpm.

If you find total is over 38 deg over 3k rpm dont just retartd the toal,thats because the initialtiming is retarded 1 deg for every deg you retard the total to get it back down where it belongs and then your right back where you started.

Then 18 inital + 18 mech in dist = 36 total which is good.

After initial is set to 18 deg you will have to reduce the idle speed & re-adj the idle mix screws due to the additonal 10 deg initial timing you just dialed in & re-attach the vac adv hose to full intake vacuum.

Then install a vac adv (hooked to full vacuum all the time) which is fully acvtivated at ilde that gives you an additional 12-14 deg if you dont already have one thats correct for your setup.

Your motor will really wake up with this proper ign timing curve from where its currently at being approx 10 deg (= -) retarded on the initial timing.

Take the time to get this right and you will be rewarded with a great running street perf motor.

Scott

i might have missed it, but do you have the vacuum advance hooked up?
if not, put it to full manifold vacuum. the extra timing will at least allow it to idle at a decent speed so you can do a valve adjustment while it's running- which can be a fun experience....
just get it to where it idles- even if it's at 1100 rpm. as long as it idles, you can adjust the valves.
pull off one valve cover, and use a piece of cardboard as a shield to keep oil from splashing all over the exhaust- the box from your valve cover gaskets is about the right size and works awesome. just jam it between the valve springs and the outer valve cover rail.
fire the motor up, and starting at the back or front, loosen up each rocker until it just starts to clatter, and then tighten it back up until it just stops clattering. do each valve on that side just like that, then shut it off. it should only take a couple of minutes per side. now, go back thru and tighten each rocker another 1/2 turn, and put the valve cover back on and do the procedure on the other side.
there, after 10 minutes of work, your valves are perfectly adjusted, and hopefully you didn't get too much oil all over the place.
now you can screw around with the timing- stock mild cams like a ton of timing, so put it at 36-38 degrees total, and use an adjustable vacuum advance can to get the initial where it wants to be to idle the best.
now, you can play with the carb, then go back to the timing, then back to the carb, and back to the timing again. eventually, it will stop getting better, and it will be ideally set until the weather changes..

removed the blue sharpe....nope didnt do a thing:D

Have you tried a red sharpe? Most SBCs run better with red.:D

It was probably a mistake to toss a working HEI in favor of an unknown version. The factory put a lot of R&D into matching up the distributor parameters with the engine and car. Take a look in an original GM factory manual and see how many variations of distributor setup they ran. It was not a short list.

But be that as it may, now the problem is to make this setup work. I would recommend a read through the "ignition 101" thread for some general background. Note that the total ignition is the most critical to not break something in the motor, so I cannot go along with Scott's recommended procedure. You really need to set the total. Then hopefully your initial is ok, because if it is not you will have to modify the distributor to reduce the mechanical advance to adjust the initial.

You will also need to verify the vacuum advance is a proper match. It may be worthwhile to see if you can swap your old can onto the new distributor if you still have it. I wound up doing exactly that to great benefit when I got bit by the "new distributor" bug myself ;-)

How much total advance you have in the distribtor??? Your distribtor may have too much advance travel in it cause the timming fall back too much and will not idle lower enough.

Oh boy, I got tons of good info in here. Thanks for all these replies. I took a break from working on the motor and decided to start with install of my SS guages. My back was starting to kill me after spending so much time under the hood. Its raining cats and dogs right now so I wont be able to apply any of this new found knowledge to till sunday. I will report back with the new findings.
Goals for this sunday,
REadjust valves
set total timing with vac disconnected @3500 rpm

we'll see what happens

Al,FYI,dont set timing for total only because in many cases that leaves the initial/base timing retarded when running a perf cam which needs approx 18 deg initial/base timing.

Also,the total timing gets checked at 2800-3k rpm and not 3,500 like you mentioned,thats having the total come in way too late IMHO,it will feel very soggy esp along with retarded base timing if that's the case,it will be a slug untill you get it wound up.

For example,if the dist has approx 24 deg mach in it then if you set the total to 36 you get 36 total - 24 deg mech in dist = 12 deg initial/base timing which is substantially retarded.

Most aftermaqrket perf cams like approx 18 deg base timing so in this example you would end up with the base timing being approx 6 deg retarded. Thats because you would have only 12 deg base timing when 18 deg base timing is required with perf cam leaves the base timing substantially retarded.

You need to idle the motor low to 600-650 rpm with vac avd unhooked/pluged to chk/set base timing to avoid having mech adv in dist partially activated upsetting base timing adj.

Then set base timing to 18 deg and then check the total at 3k rpm and then above 3k rpm to ensure it doesnt go over 36-38 deg max at or above 3k rpm.

If the total timing is approx 36-38 deg at 3k rpm and doesnt go any higher above 3k rpm your good to go,re-attach vac adv to full intake vac all the time (not ported)and then reset idle speed & idle mixture.

But if the total is over 38 max at 3k or above rpm DONT RETARD TOTAL TIMING TO GET IT BACK DOWN TO 36-38 DEG WHICH IS THE OLD SHOOL/LAZY WAY TO DO IT WHICH IS NOT CORRECT FOR STREET MOTOR,ONLY A STRIP/RACE MOTOR. THAT'S BECAUSE FOR EVERY DEG YOU RETARTD THE TOTAL TIMING YOUR ALSO RETARDING THE INITAL TIMING THAT SAME AMOUNT OF DEGREE'S WHICH IS NOT GOOD AT ALL. YOU WILL END UP LOOSING POWER,WILL HAVE POOR THROTTLE RESP OFF IDLE & AT LOW ENGINE SPEED AND THE MOTOR WILL USE MORE FUEL TOO WITH RETARDED BASE TIMING.

In this case leave the base timing at 18 deg to keep full perf of motor and pull the dist to have the mech adv recurved /reduced for approx 18 deg all in my 2800-3k rpm.

Then 18 initial + 18 deg mech (in by2800- 3krpm) will = 36 total @ 2800-3k rpm and your good to go.

You also need a vac adv for street motor that fully activated at approx 2" below the lowest idle vacuum(chk with auto transin gear) that will give you 12-14 deg additional advance that hooked to full intake vacuum all the time but not ported vacuum that goes away at idle which is not good for a motor with a perf cam.

Note:,You stated your using 87 fuel ,it will likely ping on 97 running a good perf ign curve and you will need to move upto 91 orm93 fuel so be listening for ping when you test drive the car.

Also,you stated you set the timing chain dead on,well i know in approx 1980/81 gm used crank gears on SBC that were something like 2-4 deg retartded for emissions reasons. This hurt performance so keep that in mind in case you have any tuning issues down the road as that has messed up some people in the past because it's a fairly unknown issue for your avg hot rodder that causes some tuning & performance problems.

I think i had seen one of our resident engine builing experts like Mike-wolfplace/BillK/Carl @ CNC machine or Gary from GOFAST mention something about this in the past too so give them a shout if you want to get more info on that.

Scott

Scott,

Give him/it a break on the whole "you MUST have at least 18* initial" thing. Alfred stated in the very first posting "stock cam, stock cam". So we know we are not talking about a performance cam. Further I think we would all rather he leave some throttle response and performance on the table rather than overdo it and end up with too much advance and the potential for preignition or even worse detonation.

He was going to try and set the total at a higher RPM to make sure it really was all in. Sure optimally he would probably like to see it all in by 3000 RPM but what if his curve is off and it is NOT all in by 3000?

Really rather than just setting it at 3500 RPM so we can pick on you for choosing the wrong RPM, Alfred you should run a check to see where ignition advance maxes out. Then set total timing there. And if that should be above 3000 RPM, then consider making changes to the mechanical advance in the distributor. Typically this means softer springs or heavier weights.

And, Alfred, if this setup leaves you with too little initial, well that is something else to work on. But at least it won't break anything either.

I think Alfred has a good starting plan. He is going to start by finding what RPM full advance is and setting total timing to 36*. Then he will find out where initial is and take next steps from there.

That is once it stops raining :beers: <-- in the meantime B)

Ditto on that last post.Sounds like a broken record that skips over and over and over again.They should make a sticky post for that timing rant.My last count,that timing rant was posted 1,127,358,008 times.LOL

based on what you said about the vac gauge jumping all over, and not sure about the valve adjustment, that is where i would start first-its good to have the timing close, but i dont think its your imead. problem-also, if i read it right, you can not get it to idle down, another indication of a possible vac. leak, and a rough idle can be a tight valve
with the engine running you can loosen each rocker untill it taps, then tighten untill just quite, then 1/2 turn (the engine might act funny untill the lifter stableizes) its a messy way, but ok for stock cam, or you can do the thing when the ex valve just starts to open, adj the intake, and when the intake just start to close, do the ex-roll the pushrod untill you just feel pressure, then 1/2 turn(be carefuf, the socket can push down on the rocker, and give you a false feel, i pull the socket up a tiny bit)
after you get this done, see where your at with the vac.

I agree he needs to re-adj the valves 1st to ensure they are adj correctly,then he needs to get the base & total timing corrected because we already know thats not corrrect either which can cause issues too but 1st things 1st,the valve adj.

He could buy inexpensive rocker arm clips used to stop the oil when doing running valve adjustments or he could just mold some aluminum foil over the tops/ends of the rockers to stop the oil from going all over the place .

I also run some al foil along the complete lower /bottom sid of head molded over the where the gasket seat to catch avy oil that may start away from the head.

Using the clips and the foil on bottom of head usuall keep all the oiloff the motor and engine compartment when i have done running valve adj in the past.

Since he already stated he didnt have much experience with adj valves on these motors and thought they may be adj incorrectly the running adj is a good way for him to do it in this typ situation.

Just to add to some more info do one bank at a time and reinstall the v/cover before moving to the other bank to complete the valve adj so you have less running time with v/covers off .

And lastly,just like already stated by a fellow t/c'r back off 1 rocker at a time untill it ticks,then slowly tighten it back down just untill the ticking stops which is called "zero lash".

Then tighten the adj nut 1/4 turn which will make the motor miss/run rough for a30sec-1 min untill the lifter resets/stabilizes its self.

Then tighten the nut another 1/4 turn and wait for motor to even out again.

If its a stock cam or very mild cam give it 1 more 1/4 turn down for a total now of 3/4 trun down from the zero lash point mentioned above.

GM lists their chevy v8s with stock/mild hyd cams as requiring 1 full trun down from zero lash so you are fine with a 3/4 down from zero lash .

I have found at times you can still have a little ticking when only adj the valves 1/2 turn from zero lash and going the additional 1/4 turn from 1/2 to 3/4 turns down from zero lash can sometimes stop that little ticking that would maybe be there going only 1/2 turn down from zero lash.

If for any reason the motor doesnt even back out after a min or 2 after doing one of the 1/4 turn/tighten adj to the rocker nuts just back off the rocker that same 1/4 turn and then the motor should even back out. If that happens it could mean there is a bad lifter or maybe you adj it wrong or lost count on how far you were turning it down from zero lash. In that case back off the that same rocker again untill it clicks and then start the adj all over again
tightening the nut untill the rocker stops ticking/zero lash and try 3 1/4 turns steps again down from zero lash to see if it will work ok this time around. If yes great if not back off the last (3rd) 1/4 turn you made and hopefully the motor will even back out. But if not back it off 1 more 1/4 tunr and if it still doesnt even baqck out something is wrong. But hopefully all is ok with your cam/lifters and they will take the normal adjustments. I just wanted to tell you this info in case you had a problem like this when doing the adj and didnt know what to do at that point since you not used to doing valve ajd on these motors.


Scott

based on what you said about the vac gauge jumping all over, and not sure about the valve adjustment, that is where i would start first-its good to have the timing close, but i dont think its your imead. problem-also, if i read it right, you can not get it to idle down, another indication of a possible vac. leak, and a rough idle can be a tight valve
with the engine running you can loosen each rocker untill it taps, then tighten untill just quite, then 1/2 turn (the engine might act funny untill the lifter stableizes) its a messy way, but ok for stock cam, or you can do the thing when the ex valve just starts to open, adj the intake, and when the intake just start to close, do the ex-roll the pushrod untill you just feel pressure, then 1/2 turn(be carefuf, the socket can push down on the rocker, and give you a false feel, i pull the socket up a tiny bit)
after you get this done, see where your at with the vac.

Lots of great info and help here. But I think this post by forcd ind is working from the right end. get the valves right first, then start from there.

If you can find a old valve cover and cut the center out of it. This will help keep the oil from going all over the place when you adjust your valves with the motor running. :thumbsup:

Mike,i have done the old cut out v/cover thing in the past too which works ok as you already know but using the rocker clips or al foil crushed over opt ends of rockers along with al foil on bottom of the head works just as good or better at keeping the oil controlled . Then he wont have to waste time to find a doner v/cover,go through the hastle of cutting the center out of it to use it maybe this 1 time for a valve adj not to mention having to buy a set of 2 v/cover gaskets for 1 cover.

Just my 2 cents.

Scott

Sounds good..
I have had this old valve cover so long..I thought it a good idea...
Now I need a tall one...:beers:...

shaky vacuum gauge means you gotta re-adjust the valves... do this before you mess with the timing.

Sorry I didn't read all the other post but maybe you have a vacum leak??? Spray some carb cleaner on the intake mainifold gaskets and around the carb base while the car is running see if the idle changes. If it does you got a leak.

In spite of years of tinkering with this stuff I screwed up on the valves on my own, I tried to establish zero by turning the push rods and as the lifters where not suficently pumped up yet I was setting them too tight and the result was about what you have, vaccume jumping all over and as it ran it got worse (lifters pumped up). So I reset them via wiggling the rockers rather than twisting the push rod, runs superb!

UPDATE!!!

Hey guys I just wanted to get this thread back up to say thanks to all you guys for giving some help with this issue.

It been a few months and took a few because sometimes, life, cold weather and just motivation are needed to be in place in order to work on our cars. Anyhow heres what was going on with my car.

It turns out that my valves were set way to too tight which was causing my rough idle with back firing thru carb. Because of this I wasnt even able to set my timing since it was running so bad. So Shortly after adjusting the valves I started it up and it was a night and day difference to how it ran. I was even able to set the timing. However after about 5 mins it started shaking and then i heard a metallic clicking noise that was coming from the starter area. I had a hard time determining if it was the trans or the motor making the noise so I swapped my trans out with another known good trans only to have the same noise. I then pulled my oil pan and everything was ok down there. I then for no reason decided to pull #8 plug and to my surpise the elec was smashed shut....:confused: I shined a light in the combustion chamber and too my surprised the piston looked it had just been shot peened cleaned. I knew at the moment I had to take the head off. upon taking the head to my surprise I found what looks like some sort of an aluminum of very soft iron possible cotter pin or washer. The piston, cylinder, and head or valves did not have any visible damage. They just look clean:D. So since this is just a junk yard I just slapped it back on and started up again. The noise is gone, motor is running great, and it pulls a very steady 16 inches of vacuum. Currently i'm replacing the master cylinder and rear wheel cylinders since this thing has no brake pedal. Cant wait to drive it tomarrow after 8 years of sitting.

By the way, I'll be at Bob's big boy on friday if anyone wants to meet up.

Again thanks this forum and all the people who helped me out:hurray::beers:

Steve/461RAT/,i may have missed that he was running a stock cam BUT thats why i stated in my post to him 2x that fact that:

"If your running any kind of aftermarket perf cam that 8 deg inital your running if the dist actually has approx 24 deg mech adv is extreemly retartded "


So IF HE WAS RUNNING AN AFTERMARKET PERF CAM to try advancing the initial timing and if we was running a stock cam he could obviously ignor it.

Also,yes i beat this to death here in t/chevelle but 9 times out of 10 the motors in these 25-40 yr old muscle cars have been rblt and again 9 of 10 times aftermakret perf cams are installed of various lvl's.

Then on top of that at least 6-7 of 10 people that install aftermarket perf cams dont run near enough inital timing then write posts asking for help because they have rich running issues from low vacuum signal upsetting proper carb funtion at idle and just off idle at lower engine rpms.

Or they say the motor wont idle well or idle is unstable and throttle resp is poor as is low to mid range rpm perf of moroe is running hot which can at time be due to retarded inital timing.

Thats why i beat this stuff to death because many people are not aware you need to run 3x-4x more inital timing with aftermarket perf cams and the cams mfgs dont tell you that because they cant tell you to set ign timing other then stock gm setting due to epa issues with upsetting emmissions .

You guys may in fact be be well aware of this timing thing and dont need to hear it but there are many less experienced folks here in t/chevelle that do need to understand it so since it bothers yoo just dont read it since you already know whats going on.

Scott

Well said Scott, you have hepled many folks on this site, me being one of them by going into details with timing issues. Thanks for taking the time to do so.

Jesse