Justin86camaro

ok i have an 8 inch summit harmonic balancer on my 350. i have installed a mr. gasket scale in what i believe to be the right location for the reading. i have the current timing set at 16 degrees advance at idle, when i touch the gas the car bogs down and stumbles. when i set it my ear and by feel it runs good but is reading at about 36 degrees advance at idle ( no centrifical, or vacuum added) now i don't know what the problem is but i know something isnt right. could my timing pointer be in the wrong position? i know the balancer is correct and has not slipped. any suggestions?

rjt76

Is the pointer in the 2:00 position?
Rotate the motor by hand with the plug out of #1 cylinder. Put somthing in there like a coat hanger and have someone rotate the engine by hand and when the coat hanger is at the top of its stroke where is the mark on the balancer? It had better line up with the zero on the pointer. If not this is your problem.
Once this is verified that infact the timing is correct you may have some other issues to work out like accelerator pump shot. Valve timing ect....

Justin86camaro

this was my first thought that the damper had slipped. i can't fit anything into my plug hole because it is a straight plug and my header is in the way. i'm at a stand still until i can think of something. i do believe my balancer is in the 2.00 position. i put an aftermarket pointer on that looks as if its in the 2.00 position and would go no other way. i thought that could be the problem but i just don't see how else it could go

BadAssNovas.com

Are you sure your original timing pointer was not at 12:00 instead of 2:00?

sofakingdom

iTrader: (1)

Give the engine what it wants.

If it runs terrible with it set at the wrong "number", then dinking with the "number" somehow, isn't going to make it run right.

Just give the engine what it wants.

Screw the "numbers". All they're good for, is for putting it back to where it runs right, in case you disturb it. And even that, is only of value if the balancer doesn't slip.... which is not somethin g that can be counted on in the real world.

Justin86camaro

i do agree in seting it for what runs right. i would just like to know my total advance numbers and then be able to tune it for later mods. i'm still working on it today. i the balancer is reading top dead center on the compression stroke. when i set the timing at anything under 20 degrees it runs rough. now this is all first time for me but by thinking the cam to the cranks 720 for a complete cycle, the cam turns 360 degrees then there should only be 45 degrees of available advance timing on the compression stroke right? i just don't understand how it could run better at a high spark advance at idle, then if the vacuum advance and the mechanical advance (24 total in dist) add on to that would'nt it put the timing in the intake stroke? now with this said i am thinking something must not be reading right. i've used two craftsman timing lights, an offbrand advance light and a mac tools light. i honestly don't think all of them are off?! has anyone had any kind of trouble like this before or have any suggestions, i am open and willing to try anything to get a better understanding of this!?!?!

sofakingdom

iTrader: (1)

Your numbers and engine theory understanding are seriously flawed.

Ignition timing is specified in crank degrees.

Spark is supposed to occur at the end of the compression stroke. This stroke (like the other 3) is 180° long... 4 strokes, 720° total, each stroke is ½ of a crank revolution. Therefore, a typical "street" timing curve with about 36° of "total" timing ("static" plus "centrifugal", or their computer-assisted equivalents) plus 12 - 15° of "vacuum advance", will produce a maximum advance under any possible conditions of around 50°. Well under the 180° duration of the compression stroke.

If the "number" is really that important to you, then the first thing you should do, is to find TDC by some mechanical means of piston observation. Until you have positively established that, ANY indication from a timing light is meaningless... except to get the engine to run its best, take a reading, write it down, and restore the timing to that "number" whatever it might be, whenever you disturb it. Just sticking a piece of tape on some random damper at some random point and comparing to some random stationary "mark" or "tab" and then complaining about the resulting random "number" that you read off of it, regardless of from how many timing lights you read it, is intellectual nonsense.

The engine DOES NOT whup out a timing light, read the "number" that whatever setup is stuck on the front of it happens to produce, and decide accordingly how it's going to run. The "number" is of no intrinsic value.

Justin86camaro

i see how you are right. i was just trying to make things complicated and look at them too closely. i've still been trying to get this motor right. today i set the mechanical advance up again using all different springs. the car would idle at 14 degrees advance initial, and at 47 degrees initial no mechanical or vacuum on either. i don't understand this, the car don't seem to pull hard until about 4500 rpm. the cam in the car is the edelbrock performer plus, duration 204/214 lift 420/442, 112 lobe seperation. the distributor is the accel 59107 model with a accel super hei coil. now i don't think this could affect anything but could the module be doing any of this, doesnt that just replace the points with a transistor, to tell the coil when to fire? back to work again

five7kid

iTrader: (14)

Still need to get this clarified. Are you talking about a Mr. Gasket timing tab that bolts on using a couple of timing cover bolts?

Justin86camaro

yes i have the scale with the red adjustable pointer. i am using this with an 8 inch balancer which has a scale from 0-60 engraved, i have the pointer on zero. i have checked it since the original post and does line up dead on top dead center. there is only one position for the mr gasket scale to bolt up i just did'nt realize it at first. would the module have anything to do with this problem?

rgarcia63

If your absolutely sure that rotation timing, marks, pointers and tabs are in alignment, then the problem is elsewhere and no, spark is not involved.

Have you read your spark plugs to see if the AFR is right? I know these are not the ideal conditions for reading spark plugs, but it might be running lean and need more timing.

It's best to use the manuals recommended test equipment, you can use newer tools once it's verified that there's no difference in the results.

BTW are those lights the dial back digital type, those will read more advanced than actual on multispark/ignition amplifier boxes i.e. MSD.

Justin86camaro

yes i honestly don't see anything mechanically wrong. i took my module to be tested at the autoparts store. it failed so i'm putting a new one in today or tomorrow whenever i can get the part. i'm going to put the accel 35361 performance module in. hopefully that takes care of everything. i still don't quite understand why the module would make the car do that. the timing light reads off the spark in the wire then reads the damper. but i will install the module asap then time it and see what happens. oh yeah and i don't have any kind of msd box of anykind, just the super hei coil and 59107 dist.

rgarcia63

I actually expected it to be something mechanical.
This is interesting, keep posting - Thanks RJ

Justin86camaro

i'm getting really frustrated with this. i put a new module in because the old one tested bad, but still seemed to work fine. i put the accel 35361 module in and it is doing the same as before. i did'nt expect the module to fix it. i just don't understand why the car runs great at such a high timing reading. could it be a carb problem. possibly be tuned so badly that it needs that much spark advance to run good? i don't know and right now am geting really mad at it. it also bogs when you touch the gas in low gear and sometimes cuts off

rgarcia63

Questions:
Did you recently install the balancer, why?
What else did you do? gears & chain?

Justin86camaro

i jumped the gun and quickly assumed the stock balancer had slipped so i replaced it with a summit performance replacement. after i installed it i still had the same problem. the balancer marks lined up perfectly. i then pulled the #1 plug and verified that the mark was dead on. and it was. its almost as if the timing light is bad, but i've tried two craftsman lights, a mac tools, and an off brand. they all gave the same reading. the cars runs alot better at 40-50 degrees initial advance from the reading i'm getting. i just don't understand it the car pulls decently throughout the rpm range, when it hits about 4500-5000 it pulls even harder until i shift at 5500. it also bogs in low gear when i touch the gas, i think it could need a little more advance but my reading has got to be flawed somewhere. plus 45 degrees in the max advance for each cylinder. any more the rotor would be on the next cap terminal. oh yea and i have not pulled the timing cover or chain.

Justin86camaro

anyone have any clues or guidlines i can use to help solve this problem?

rgarcia63

Justin the statement you just made;
Indicates that you're specifying distributor degrees, if so the statement is correct.

In your original post you stated;
which indicates you're specifying crankshaft degrees, if so this statement is also correct. (Sofakingdom pointed this out to you.)

But, you can't use one number for both because the crankshaft rotates twice for every camshaft rotation i.e. 36 crankshaft degrees equals 18 distributor degrees.
FYI
Because the vacuum advance control unit is part of the distributor 8° of maximum vacuum advance produces 16 degrees of ignition advance in relationship to the crankshaft.

The only thing that I can think of other than mechanical timing like cam, crank, and piston relationship is that it actually needs more timing to burn all the fuel at idle which to me would indicate a lean condition, yes, lean mixtures do take longer to burn.

If you want to rule out mechanical timing, you can make a piston stop from an old spark plug by hollowing it out and putting a threaded rod through the center of it to reach the center of the cylinder and lock it down with a nut on either side of the spark plug body and install it as you would a spark plug, then use the "Best way to set TDC" procedure thread currently under discussion.
https://www.thirdgen.org/forums/tech...y-set-tdc.html
One you verify that the crank, timing pointer, or stock timing tab are all in alignment when the piston is at true TDC, then the timing gear dots should align at 6&12, or 12&12 O'clock depending on whether the piston is at the compression, or exhaust TDC.

I'm all tapped out - Good luck and please post any new findings, or the fix - RG

Justin86camaro

alright thanks i'm taking it to school today to look at it some more. there are three ase master techs there maybe between everyone we can come up with something. thanks for your help

Rodsride87

The original timing for the 87 CCC ESC was at 12 o'clock... few years ago I did an engine swap to a 350 and new balancer with the timing tap NOW at 2 o,clock! However the timing is now looking way off because of GM's electronic timing delay to show the timing at 12 o'clock! The engine runs great but i'm doing timing adjustments just based on feel and sound... so far so good! this week i'm figuring out where to put the timing tape to finally sort this out!

OrangeBird

iTrader: (1)

You may want to look at the dates of the posts you respond to, this thread has been cold & dead since 2006, and in the 16 years since I'll bet he's got it sorted.......