[Wildwestshow]

i have a timing problem with my chevy 350 small block quadrajet carb headers hei distributor new plug wires new spark plugs

ok my problem is my motor will not run smooth when it is time 8 degrees before top dead center its 99 percent stock except headers it lugs when i put it in gear and if i try to put it at 8 degrees it has no power but at say 16 it has a little increase in power but not what it should and runs great but its 16 degrees before tdc?? and wont run smooth any lower i beleive a 350 calls for 8 btdc but it only runs at 12 any lower nothing

[Greg T]

Limit the amount of travel in the mechanical advance weights to about 18* and set the initial at 18* with the vac advance unplugged and the idle at about 650 rpm. Also, use some lighter springs on the mech advance to bring it all in sooner. Then, plug the vac advance into full manifold vac. Should run like a scared rabbit.

[Wildwestshow]

ok i will try that tomorow does orielys or napa sell a kit for it and what kind should i get?

[Custom10]

A good kit that may help you:

http://www.cranecams.com/pdf/Page607.pdf

One thing that it will not address is the mechanical limit, this you will need to set with some type of travel stop on the rotor plate but I am not sure exacly which HEI you have.

The vacuum advance will need to be limited as well, the plate is in the kit. If you go 18 base, + 18 mech as gregT said, the vaccum adv should be limited to 12, this will require that you set the limiter plate near the last notch on the big side. That would bring your total timing to 48.

You can start with say one heavy spring and one medium/light spring and see if you can get your base + mech to be all in at about 3000rpm with the vacuum adv can disconnected. At idle with the vacuum can connect to manifold vac you should have just over 30 deg BTDC if the mechanical is not coming in as well which is something you want to avoid, the springs will determine this and having one heavy one in there should keep it out below 800-900 rpm.

2 more of my cents

[Mohocomo]

Chevy makes 3 dist's with 3 different timing setting. Depending on which dist you have maked the difference in initial timing. I do not like to curve a stock motor, I curve one to match an after market camshaft and remove the vacume all together so it always runs at the max curve in the powerband of the camshaft. If you do not have an after market camshft in it, using both the soft springs can still cause it to still bounce. May need a med on one side and soft on the other if you choose to try a kit.

[Wildwestshow]

mono what ur saying is since my motor has no aftermarket cam in it would u recomend just buying a new hei dist?

[Mohocomo]

No, there maybe other issues. Have you checked the mark on the balancer? I have seen them slip and be off big time, so 8 maybe 16 or 5 etc.. in reality. Have you put a vacuum gage on the motor to see what the vacuume is while changing the timing? Have you checked the timing at 3k rpm's? If you have is it in the ball park of what it should be(36)? If not you will have to make a new mark on the balancer which is a job but can be done. How did you adjust the carb? Headers usually run a little diffenrent on adjustment screws then stock manifolds, usually a round and a half more. If you have the floats set on the carb. screw the adj screw in until the motor missing slightly back it out 2 to 3 and half rounds for headers and 1.5 for stock manifolds, start at 2.5 Do both sides the same way. Of course if you screw the screws in and there is no change in the motor that is an issue as well. I find it hard to beleive timing would cause an miss, maybe kill the motor or make it slugish but not miss. Have you checked the plugs? On the porcelain portion of the plug what color is it? It should be paper bag brown if it is black it maybe because you did not back the screws out enough. Drive it for a day or two and see if they clean up. Also check the heat range on them while you at it. Also take a can of wd40 and spray the intake and around carb while motor is running, if it dies then you have a leak. I also had a fuel pump one time drove me crazy because it caused the motor to miss at idle, like to have never found it. Good luck

[Mohocomo]

Sorry on the miss, I am reading 2 threads and the other is missing.

[Wildwestshow]

alright my 350 is now at 8 * btdc now the problem is while im in park i get good throttle response but when i put it in gear if i tap the gas instead of responding like a motor should it almost dies and lugs out and another thing if my vacumn advance is hooked up while idleing it brings my timing mark up but if i take it off it shows 8* any ideals im thinking carb on both problems like i said before i have a quadrajet not sure of cfm or anything else just electric choke and 4 barrel all i know about it tomorow im going to place the motor on tdc and take on the left side valve covers and see if my rocker arm is flat and to adjust my valves thats the only ideals i have about the lack of response while in gear