MIKE- its here, its here

[bigd65]

It finally came , i got the CRANE vacuum advance can and the the springs, im going outside to put it on now.

Well after i read your article, THEN i am going out to put it on.

[swervin ervin]

Great.

[bigd65]

Well its in and guess what i still have the spark knock. it is set the same way that DAMON ,on your article, says to set it , i even have the advance lock out plate on and on the 2nd to last notch, where most of it is locked out. the initial is et at 10 and when i hook the vacuum advance to manifold it jumps straight up if not it is close to straight up. i would say it would be about the same maybe a little more than the length of the timing mark itself. the advance can is set 10 turns counter clockwise from fully set position. also i have one blue and one silver spring, maybe i need 2 blue springs ?. come on Mike help a brotha out here.

[swervin ervin]

If you followed the article to the letter, there is no way it should have a spark knock.

Did you scroll all the way to the bottom and go by my HEI Tips. I used both blue springs in my old distributor. The one blue and one silver wouldn't work for me either. The blue/silver setup I feel works good for lighter cars, but with these heavy trucks, I couldn't get it to work for me either. Use both blue springs.

[bigd65]

That was what i was gonna try tomarow, had to do the family thing and went to the movies.

anyway, i thought i would try the way Damon said to first but that i read the instruction for the third time, it even says will probably need both blue for heavy vehicles(RV,TRUCKS,ETC...)

another question, with the initial timing set at 10* with the vacuum advance disconnected ,at 10* what should the timing jump to when i hook up the vacuum advance.

[swervin ervin]

OK, first. The bottom part of the article on my site was wrote by me. This is what I did to my old stock distributor. I'm the one who says to use both blue springs, not Damon.

Now, if you set the lock out where I have a arrow pointing to, you should have around 16 degrees vacuum advance. This is where you need it if you still have a working EGR. I think you don't have one, right? If you don't have a EGR, you need to lock out all the vacuum advance you can, which will leave you with around 12 degrees. It just hit me what was wrong with your setup besides the springs.

So, first thing I would do tomorrow if I were you is first, move the lock out to the maximum lock out setting, which is all the way over to the last notch, not the second to last. Then check the timing and see how much vacuum advance you have. Should be around 12 degrees.

Test drive it. It may be fixed and not spark knock, without changing the silver spring to the blue. If it works this way, leave the springs with one silver and one blue. This will be best for performance. If not, swap out the silver spring for the other blue and try again.

I think the lockout will fix it. If it doesn't fix it, the blue spring should for sure.

Timing is an experiment. No two settings are the same for everyone. Even on the same type vehicles. Your truck is heavier than mine being a long bed. Timing is affected by weight, as is torque, stall speed of the converter, etc.

There is no one setting for total mechanical advance. It's a game of try and see. Every engine, tranny, rear gear, truck, etc. will be different. There is a close setting though. Then it's once again, try it and see what happens. Only true way to find out if it works, as in helps performance is to time it, as in on the strip. But you and I don't drag our trucks or have access to the strip, so it's a seat of the pants test.

Most all SBC's run best in the 32-36 degree range of total mechanical advance. A stock GM HEI has 20 degrees built in with the weights. So, with this in mind, it means you need 12-16 degrees initial advance. Vacuum advance is not for performance, but for economy and good manners on the street. Now, the rate of the advance is what makes or breaks performance. You want it to come in as fast as it can but without detonation (spark knock). The faster, the better. It's best if it starts right off idle (in the 800 rpm range) and is full in by 2800 or so. This is where the one silver and one blue springs are supposed to operate. Both blue springs will start around 800-900, and be full in at around 3200. I tried a silver/blue and it wouldn't work for me. I guess maybe with my EGR working, I don't know. It may work for you.

So going by this, make the changes I said to do to the lock out. Leave the springs with one silver/one blue. Set your initial at 16 degrees. Test drive it. If it spark knocks, lower the intitial to 15. Try it again. Knocks, try it at 14. Keep going until it quits or until your reach 12 degrees. If it still knocks at 12, change the spring to the other blue. Now raise the initial back up to 16 degrees. Do the same steps as before. Don't go past 12 degrees though. What you are concerned with here is not the initial amount of the timing, but the total. Never concern yourself with the initial. You want the most you can run and not spark knock. On the initial, all you are after is no spark knock at cruise and easy starting, especially in hot weather. All this my fly out the window next summer. Then it's back to the drawing board.


Try these stesps exactly how I've outlined them here. You will get it. Don't panic because this is not a quick process.

Mike

[bigd65]

OK, thats what i am going to dofirst thing the morning.

what is confusing me is you say start at 16* is that with the vacuum advance hooked up or 16* set at the distributer, no vacuum advance hooked.

that just seems like a lot of advance. believe me, i know you know a hell of alot more about timing than i do, but it just seems like a lot of initial. I AM GOING TO DO THIS IN THE MORNING AND I WILL POST THE RESULTS.

THANX MIKE

[swervin ervin]

Jeff,

it's 16 initial. Initial is no vacuum advance. Remove the vacuum hose and plug it to set. Then hook the vacuum advance back up when done.

As far as being too much, I have a total of 35 degrees mechanical advance. My MSD distributor has 21 in the distributor and 14 initial. I was running 36, i.e. 15 initial, but backed it off 1 degree this past summer. Any engine can take more timing in colder weather. This is why they ice the intake between runs, to cool the intake charge. Drag racers absolutely love cool dry weather.

It's all got to do with compression ratio. The more CR you have, the less initial you will probably be able to run. If I remember right, your CR is around 9:1 or so, Mine is about the same and it does great at the above settings. But I do have a EGR, which helps to cool the combustion chambers somewhat, hence the reason you can run more vacuum advance with a EGR.

Good luck and please report back tomorrow.

Mike

[bigd65]

WELL, here is an update.

i even went back to basics and started the exact same way DAMON said to do it and that is start at 16* (with vacuum advance disconnected and drive and decrease till the spark knock is gone or untill i get to 12*. if the spark knock is still there, then go to both blue springs ( that may have been you MIKE) anyways im at two blue springs. the vacuum advance is completely locked out, well at least at the last whole. the rod barely moves now maybe 1/4 or less. everything is maxed out and the timing is at 10* and i still have the spark knock. i am still wondering if the coil may be the problem. as i said it is advertised at 54,000 volts as the stock is 38,000 if im correct. that is the only other thing i can imagine. everything else is new, pick up, module (MSD) everything. this thing is reeeaaaallllllllyyyyyyy getting on my nerves. i think i am starting to understand more of what i am doing with it, but the knock will not go away

[swervin ervin]

Well, damned if I know what to tell you. Do you think the carb is too lean?

I don't think the coil will cause spark knock. You have problems somewhere else for sure. There is no way you should have spark knock with this much vacuum advance locked out. Did you test drive it with the vacuum advance hose removed and plugged? Have you checked to see how much total advance you are getting, not counting vacuum? How much vacuum advance do you have now?

Something is wrong for sure. Only other thing I know to tell you is check the carb to make sure it's not running lean. Make sure you don't have any vacuum leaks, which of course will cause it to run lean.

If all else fails, and you can't get it to quit spark knocking, and everything is the way it's supposed to be setup, it may be time to try another distributor. Something just isn't right here. There is just no way this thing should be doing this. Only other thing I could think of for a remote chance is carbon buildup on the piston tops. You could try some top engine cleaner, or some tranny fluid poured real slow in the carb. It will smoke like a freight train, but if anything is in there it will clean it out. I've done it before and it does work to clean out the combustion chambers.

Mike

[ElGracho]

I've followed this conversation all the way through and might have another idea what's wrong. I think you may not be accurately able to find out what your timing is. I think this is either due to a harmonic balancer that has "slipped" (the outside ring moved relative to the inside) or your timing pointer isn't right for the mark on the balancer. I've heard of this happening and even seen a balancer that had "slipped" but never had it happen to me. Just another idea.

[swervin ervin]

Good idea Joe. Never thought of this, but it does happen. Thanks for bringing it up.

Only way to find out would be to of course, find true TDC. Jeff, do you know how to do this? It involves using a piston stop in the number one plug hole. Take all the plugs out to make the engine easier to rotate, then:

You screw the stop in the #1 plug hole, rotate the engine by hand, slowly in one direction until it makes contact with the stop. Don't go fast or you risk damage to the piston. When it makes contact, mark the balancer at the zero on the pointer. Now rotate the engine the other direction until it contacts the piston stop once again. Mark the balancer again at the zero on the pointer. TDC will be exactly center ways between these two marks. If it's exactly at the groove on the balancer, it's right on.


Jeff,

I know your nerves are shot with this crap, and believe me, I know how you feel, but we have to try all possibilites. Like I said eariler, there is no way you should be having spark knock after the mods above.

[85 K5]

Ya know mine's the same way. Crane kit - 2nd notch on lockout, nine turns out on cannister, initial 10 deg. Stock HEI and EGR. RV cam.

Spark knock happens in 4th gear, 1000 to 1800 rpm while cruising, uphill side of overpasses and such. Have good power, however.

Our differences are:
1. Thermostat - I have 190
2. RV cam versus ? 262?
3. Eddie 1904 jetting, maybe ours are leaner (been a while since I've read your Qjet tips)

Can any of these differences have an impact and if so how should we compensate? What about 1 blue and one stronger?

Other thoughts are quality of fuel - I think I might try some octane boost and see what happens. Also considering forking out the $60 for dial back timing light.

Thanks for letting me butt in!

[bigd65]

Mike you said something about the carb being to lean, i have checked it for leaks, no leaks, i even put .98 jets in the secondaries from the .95. it still does it. It damn sure aint lean on the idle cercuit cause i still cant get it to lean out any there. i get it set right where it is smooth idling (to make a long explanation short, i know how to adjust a carb) and it still burns my eyes. but that aint y problem at this point.

I'm thinking ELGRACHO maybe right about the H/B slipped, cause if something else would be wrong it would have the clatter all the time. i can set the timing marks at TDC and the clatter is gone.I get good milage, drivability, and performance. with it set where it is right now, it dont break the tires as easy, it stll will but not as easy. it sounds like it is too far advanced. i guess my next adventure is a H/B. well after i get a tranny for the daughters 89 ACURA INTEGRA. I KNOW ITS A RICER BUT SHE IS 17 AND YOU KIDS NOWADAYS, YOU CANT TELL THEM ANYTHING.

You asked if i drove it with the advance disconnected, yes and it still had the clatter.i think im gonna back track alittle today and with both blue springs keep backing the timing off till the clatter stops, then replace one of the silver springs and see what happens from there.
Then i will start with the advance can. do you think i should with it locked out on the second notch and still the 9 turns ?

I GUESS THE NEXT STEP WOULD BE A MATCH IN THE GAS TANK

[bigd65]

well it wasnt the tranny on my daughters car, just the CV axle shaft. i just replaced it, oh well its under warranty.

anyways, how about the 1 inch spacer i have under the carb, could this be the problem ?

[swervin ervin]

Jeff,

first thing I would do if were me would be to check the balancer to make sure it hasn't slipped as Joe said above. If the balancer checks out good, there is something wrong somewhere for sure. If it spark knocks with the vacuum advance not hooked up, you have something wrong beside timing settings.

I said this before, you can't diagnois timing troubles without a dial back light or at least some timing tape on the balancer. Also, Proform makes a real neat balancer cover which is laid off in degrees which is perfect for this. I have one on my truck. It's a real neat item to have. You need to figure out how much total mechanical advance you actually have. Guessing won't cut it.

Here's the one I have.