The worn plate would be under the pertronix you have in there.....I also have a piston stop you can borrow , I drive through san jose everyday..
I might take you up on that, however, i'd like to have one in my tool kit to use at a later time on my pick up. Thanks for offering though. Is the thread size 14mm for the plugs?
The 350 one might fit but better to find another 340 version. If you climb under the car you should be able to get a good look at the rubber to look for cracking. First thing to do is find out if it has slipped or not. You never did answer my question about if the vacuum advance was connected when you were checking the timing.
Yes I answered earlier. i should have been more clear. I removed the hose from the carburetor side and plugged it with a screw to disable the vacuum advance.
No sweat...if you want to borrow it just let me know. I still have a hard time believing the balancer slipped that much, You can get fairly close by just removing the spark plug and turn the motor by hand and use a dowel to " feel " tdc. You will at least know if the balancer has moved. I still think your just way off, besides if the mark while running is on the passenger side it would be just wayyy retarded. Could just be the clamp didn't hold and the distributor moved on it's own. Try moving it while running and see if it speeds up while bring it back over to the drivers side and timing tab.
IT WOULD BE PRETTY EASY TO USE A KNOWN GOOD ADJUSTABLE LIGHT TO TELL YOU EXACTLY WHAT THE TIMING IS READING? Unless your using a dial back light how is the mark ever gong to be at zero at idle? o No:
should i block off all possible vacuum ports in order to get a more precise timing reading? ---------- Post added at 10:26 AM ---------- Previous post was at 10:25 AM ---------- previous times that ive checked the timing without a dial back knob, i was able to line up the lines pretty close. i'm going to invest in a dail-back knob though.
according to this pdf http://www.teambuick.com/reference/library/67_chassis/files/69-a.pdf timing is to be set 2 1/2* before top dead center. However my balancer mark is WAY off. So, i'll be using this guide as my instructions. But if the balancer is that off, how accurate of an efficiency can i get in the engine? this guide shows how to time with a vacuum gauge, i think i will try it also http://automotivemileposts.com/garage/v2n8.html im slowly beginning to understand the whole timing, advance adjustments.
You don't understand at all. That is not the right way to adjust your timing. All you need is a dial back timing light and the instructions in my Power Timing thread. You set the total timing, and that is it. It isn't rocket science, and it never ceases to amaze me how confused people are about this simple adjustment. It's the sole reason I wrote that Power Timing thread.
steps to follow 1-hook up dial back light to number 1 cyl and power and ground 2-make sure wires are clear of all moving parts 3-disconnect vacuum adv hose if in use 4- start car and idle 5-point light at balancer/timing tab 6-adj light dial till mark on balancer lines up with 0* on timing tab 7-this is your intial timing at idle 8- rev up car and watch mark move and adj lamp again to reach 0* on pointer again 9- thiis is your total mechanical advance 10-easy peasy lemon squeeezy Any other way is innacurate and a waste of time Good luck
at what point in this process do i rotate the distributor clockwise or counter clockwise? i get that dialing back the timing light will tell me what degree advanced or retarded the timing is. But how do i know what timing is correct? o No: ---------- Post added at 09:01 PM ---------- Previous post was at 07:59 PM ---------- so what am i doing wrong? according to your post, i'd rev up the car to where the advance stalls using the timing light and then clamp the distributor down? I have a bone stock 340 nothing special other than the accel pointless conversion.
I think we're getting a bit carried away here. Let's go back to basics and look at this logically and (hopefully) scientifically. You're original complaint is that the timing mark appears to be X degrees off, though the engine is running well. We're gather you're definitely using cylinder #1 for the timing light trigger. First thing to do is verify Top Dead Center position of of #1 piston using a piston stop as was described in post 19 and then look at the balancer to see where the balancer's TDC timing slot aligns in respect to the factory timing mark when #1 is truly at top dead center. Do this first and do nothing else if the balancer's slot does not closely line up with the factory timing mark. If physically finding #1 at TDC is confusing, report back with questions. Devon
ha way to reign everything in :TU: i'm getting the car out of storage tomorrow, got my piston stop in the mail already so i will find TDC tomorrow and report back. 1 question before i get to it, the TDC that i determine tomorrow is not necessarily the compression or the exhaust. It's just straight up TDC of the entire stroke. It shouldn't matter which stroke, correct? FYI the car does not run as good as it should, it has a noticeable shake to it especially at stop lights, but no pinging
Yes, you got it right. The piston comes up to the top on both the compression stroke and the exhaust stroke, so the groove on the balancer should meet the zero line on the timing indicator every time #1 is at the top. It's the job of the camshaft to take care of the valves between compression & exhaust strokes, which is why the camshaft rotates 360 when the crankshaft rotates 720. Get that check done and we'll go from there. To hell with "power timing" until you take that first step. Devon
alright the results are in The piston stop method proved that the harmonic balancer is still pretty accurate within a centimeter (i think my shaky ass hands had some to do with the mark not dead center) Now when i checked the timing after verifying the balancer at idle, with advance connected to carb, i had to bring the Dail on the Timing light to 20* in order for the lines (balancer to tab) to match up. With the car revving at 2500 rpm the dial was up to 60* (im sure this is totally inefficient and inappropriate for the car) This had the engine making a loud slapping noise from the engine bay. I did not adjust the distributor here to get it to 20*. This is the car as it has been. -------------------- (the following is me messing around but still need some good direction from the board) I adjusted the distributor to 2* BTDC (with vacuum advance plugged and disconnected) and it smoothed the engine out considerably, but it still has a noticeable shake to it but eliminated the slapping noise. The rpm's at this point read below 400rpm in park at idle o No: I plugged in a vacuum gauge at the ported carb port and it read below 5 lbs of vacuum. When i revved the car up pretty high, it was able to reach 17-18 lbs of pressure. -------------------- At this point, i have cinched the distributor down at 2* BTDC. the car starts and shuts off normally, although there is still that shake. So what do i need to change here? what reading should my timing light be set to? what did i do wrong here and what should i re-do? thanks guys!
You will need to raise the idle speed using the screw on the driver side of the carb where the throttle cable goes. Once at the correct idle speed the vacuum readings will be higher. I also like to set the idle mixture screws on the fron tof the carb so that I get max vacuum at idle in gear. I do this with the wheels blocked. It is a good idea to find out your total timing, so check that and let us know. I find these engines like to idle at 8-12 degrees but the key is not having too much total timing.
when i attempted to bring the idle up closer to 560 (as the book describes) it sounded like the engine was running down the freeway. I almost had to screw the all the way in for the rpms to get close to 560. So you adjust your carb mixture screw with the car in drive until the vacuum gets it highest reading?
It sounds like your idle mixture is off if you have to use a lot of pre-load on the idle screw to get the speed up. How I do the idle mixture screws is this: -Remove and plug the line to the vacuum advance -Put the vacuum gauge onto a line that gets vacuum at idle -block all 4 wheels well and set e-brake -Screw the two idle mixture screws in till they LIGHTLY seat. These are on the front bottom of the carb -Screw them out 2 full 360 degree turns -Start the car and set the idle speed to spec -Put the car in drive and watch the vacuum gauge. -Try screwing the idle mixture screws out half a turn each -If the vacuum reading goes up then screw them out another half turn -If the vacuum reading goes down then screw them both in a full turn (this puts you at 1.5 turns out) -Keep track of this with a note pad so you know how many screws out you are at. -Fine tune it till you get a qaurter turn and still getting more vacuum -Re-set idle speed as needed Some people just set the mixture screws when idling in park but I like to set them when under load in gear, it works better for me.
thanks for the steps. Thats basically what i've been doing to the carb, except while in park. But i think the timing had to do alot with everything not being in sync. so according to your previous post, i should advance the timing 8-10*? then rev to 2500rpm and check the total timing with the vacuum advance disconnected and plugged?
I wrote this article for my club newsletter. Here is part of it I can't make it any simpler than this. Setting up your total timing is easy with an advance timing light. Use the lowest tension springs available. This will make the job quicker and easier. Remember to disconnect and plug the vacuum advance. Clean the timing tab of any oil and or grease, and highlight the balancer mark with white paint to make it more visible. Also loosen the distributor hold down bolt just enough, so that you can rotate the distributor by hand. To begin, turn the knob to the degree setting that corresponds to the amount of total timing you want. When you point the light at the balancer, realize that the balancer mark will appear below the 0 on the timing tab. Slowly open the throttle. As you rev the engine, the balancer mark will move upwards. Increase the engine RPM until the mark stops moving up. That RPM will depend on spring tension. The total timing will equal what you have the timing light advance knob set to, when the balancer mark is aligned with the 0 of the timing tab. If the mark stops moving upwards, and it is above the 0 on the tab, it means you have more advance than you want. Turn the distributor clockwise to retard the timing, and try again. If the mark stops moving, and is below the 0 on the tab, it means you have less advance than you want. In this case, turn the distributor counter clockwise, and try again. Again, you want the mark to stop moving up when it is aligned with the 0. It may take several tries to get it correct. Move the distributor in small increments. Remember, the distributor is driven at one half crank speed, so one degree of distributor rotation, will equal two degrees at the crank. When you are finished, tighten the distributor hold down carefully, and recheck your timing. Change the weight springs to ones that bring your total timing in, at the RPM you want. For street cars, 2500-3000 RPM is best.
