Did you do this yet ?

 

6 by 8--So yesterday was one of those days where I just had to take a step back, walk away, regroup and get back at it later. We’ll see what happens later today, but my goal is to get the voltage reading on the coil and advance the timing and take vacuum readings. Speaking of the coil, I realized last night that my question about the coil was foolish, but I wasn’t going to get out of bed just to edit my question. I just wasn’t thinking when I asked that question. I realized the high voltage output happens through the coil wire, not the + and – coil terminals. Like I said, it wasn’t my day yesterday. I guess we all have those days.

To answer your question, yes I did feel the power loss when I dropped the timing down. It feels more sluggish than it did with more advanced timing.

Question about the coil…you made a comment stating that you hope I’m only seeing 12v at the coil. So what does the voltage at the coil have to do with timing, pinging, etc….??? Does it have an effect on it? I didn’t think it would have anything to do with it, but I could be wrong.

To answer your question…yes the cheap gas I’m using is 87 octane, but the supreme is only 91 octane. That’s the best we can get in Washington.

Yes, when my idle timing was at 14* it was pinging at 2000 rpms. That’s pretty much when it starts. What does that tell you? Is that a sign of something?

My gut feeling is to wait to dial in my timing until I am able to use the supreme. Otherwise, isn’t this all for nothing? Won’t I have to start over with all of this once I am using supreme gas? Your thoughts? I’ve been driving the Bronco to work everyday this week trying to use the gas. I’m almost on a ¼ tank, so it will be a few more days until I’m ready to put supreme in it.

Regarding my truck……So I wanted to verify a statement you made and make sure I understand you correctly, because if I get this wrong I could have another engine meltdown. You stated, “With regard to the weight of your truck, it should not have any bearing on your ignition timing and pinging”. So let me make sure I get this right. If I dial in my timing curve on my truck to come all in at (for example) 2500 rpm and there’s no pinging at WOT, then when I hook up my 8200lb trailer and pull a 6% hill at WOT in the hot summer weather, you’re saying I’m not going to have any issues with pinging? Am I understanding you correctly? It was my understanding that weight has a lot to do with how soon you want your timing curve to come in at. Am I wrong??? I’m currently using the two heavy springs and it comes in at 3500 rpm right now with the idle timing set at 18*. But if I can get the timing curve to come in sooner, like 2500 or 3000 rpm without pinging, I’m hoping it will give me more power. I can’t get the 3500 rpm peak down any more than it is because I’m already using the black bushing (18*) and that’s the smallest numerical bushing they offer. So if I change the springs to allow my timing to come in sooner, I won’t be able to change the peak rpm of the mechanical advance.

Matthewq4b--Regarding the vacuum advance canister….I finally got an email back from Summit Racing today and they stated that they (MSD) don’t make an adjustable vacuum advance canister for my distributor. So I’m going to have to try searching for one like you suggested. But I’m going to wait on that until I’m able to figure out the timing curve when I’m running supreme gas.

 

LOL, that's funny.

You are overdosing on information overload I reckon, but yes, we do indeed have days like that.

Excellent ! Now you know what ''too retarded'' timing feels like.

Or we could say, not enough advance timing, or, in this case, not enough octane for the engine's design.

Basically you have now 'felt' the effect of a few degrees change in timing,hence that's why people say, ''keep advancing during WOT tests and back off 2* when there's pinging'', coz that's maximising the available power.

Your current dizzy/coil combo does not need a resistor wire, but if a resistor wire was in the circuit, 12v instead of 14v feeding the coil, would give you the same effect as the retarded timing you just experienced.

Timing and pinging has an effect on engine power.

The timing curve is part of the ignition system, but so too is the dizzy, coil, HT leads, and spark plugs, and that's why I mentioned testing the coil voltage.

One can test plugs and HT leads too !!

The 4 increase in octane will be fully appreciated and understood when you compare the 'final' future curve to today's curve.

YOUR timing curve, as plotted, told me that pinging would be observed at +/- 2,000 rpms. Cool huh ?!

You already know what it's a sign of !! (I.E. Nothing new, it simply confirms what we know already.)

Your gut feel is spot on about dialling in the curve now, and more importantly, it means that you are understanding what you are learning.

More to follow.

 

Since I'm running a MSD 6a ignition box, im pretty sure the coil is getting 14v. But I'll find out later tonight.

 

With regard to 1 above :

You're beating yourself to death with 'what if' scenarios.

Once the 1/4 tank of 87 crap has been used, and you have the 91 mojo filling the tank, you are then going to set, and verify, the timing curve.

The engine, and only the engine, will tell you, in engine talk, what it does or does not like.

The 'all in' timing will be what it will be, and the speed at which the curve advances, will also be what it will be.

Let's say, as a pure example, that your timing ends up at a total of 34* all in at 2,600 rpms. So be it !

Running an engine at WOT, means running an engine 'fully loaded'.

Driving up a 6* hill with a heavy trailer will be close (?) to fully loaded.

Therefore, no pinging at WOT should also mean no pinging during a towing load.

Funnily enough, I was going to tell you to test your truck with the trailer after your final dial in.

With regard to 2 above :

No, you are using one heavy and one medium spring aren't you ?

I sense confusion.

Your current timing is 14* + 18* = 32*, all in at 3,500 rpms.

You might go to say 16* + 18* = 34*, with the 91 mojo.

The 18* is static. (It's also quite sh$t that MSD offers such a small choice of limiters. A 14 and 16 would be very useful.)

Using 34*, this will be ''all in'' at 2,500rpms or 2,800rpms or whatever.

So yes, you can drop the 'peak'.

With regard to 3, which isn't above, LOL :

 

Actually no, back to 1 quickly :

I towed a big heavy trailer with a racing car on it a few years back on a warm day, but on flat roads.

The weight could well have been +/- 8,200 lbs.

I drove at WOT several times, and no pinging at all.

The only thing I noticed was a huge drop in acceleration speed. LOL

Ok, point 3 :

You had mentioned that pistons were destroyed by a broken dizzy spring.

I don't think I've fully digested that one yet !

Let's say that that engine also had a curve of 14* + 18* = 32*.

The timing could never exceed 32* (ignoring vacuum advance that is) because the limiter sets the limit.

A broken spring would simply effect the speed at which the 32* is achieved.

Pulling a trailer up a hill implies that your rpms would have been at least at 3,000, which is +/- your all in level (limit), and engine vacuum would have been low to zero, thus not advancing timing by much or by zero.

Hmmm, enough said.

 

It's been a decade or so since I last talked about, or considered, an MSD 6A.

I think at the time I decided that it wasn't really needed on a street engine, but I can't remember for sure.

If you have it installed, fair enough.

 

I am running the 6a box because the 8477 distributor requires the use of an ignition box. Yes, my Bronco (and truck) both have factory ignition boxes, but I had another MSD 6a box laying around so I used it. Besides, they're better than the factory unit.

Ok here's the results of the vacuum and voltage tests. First the vacuum.....10° = 17", 20° = 19.5=, 25° = 20".

Now for the voltage test. Battery = 12.66v (engine off), 14.06v (engine running). But the results of the coil voltage have me really confused. It registered .55 volts. I touched the red cable of the multimeter to the positive terminal on the coil and the black cable to the negative side of the coil. Yes you read that right, it registered .55 volts. This doesn't seem accurate? Does this have any to do with the use of the MSD ignition box?

 

Regarding the answers to #1 & #2, I wasn't talking about the Bronco, I was talking about the truck. I have 2 heavy springs in the 460 (truck) and 1 heavy and 1 light spring in the 400 (Bronco).

 

Ok Fist off you measure the oil voltage from the Coil + to chassis ground or the battery Neg . NOT the coil -, the coil -/neg is the trigger for collapsing the field and is open when the engine is not running on basically all electronic ignition systems to prevent coil overheating.. The basic stuff and not sure why any would suggest measuring to coil- and unless they had zero clue what they are doing.

Also if you set up your advance curve with no pinging with no load then load the truck up and start pulling a hill in hot weather you very well could get pinging, As you load an engine up you starting increasing combustion pressures and in turn temperatures, this is equivalent to increasing the compression ratio.

So if your timing is set to maximize horsepower it will lead to lead detonation if the timing is not dialed back for a buffer margin.. What has no pinging unloaded may hammer like a rivet gun when loaded. Anyone who says that you won't get detonation cause you do not when unloaded has no functional clue what the F they are talking about.

This is why I suggested setting this up on regular fuel as if you run premium it gives you that cushion for towing, and since it is a truck and will get used as a truck and not a street/strip car you are going to have make compromises and that tmeans leaving some potential power off the table to have that cushion for when loaded.

Ignore the ignition curve plotting it means nothing with out quantifiers and is completely useless. And this coming from a former Ford engineer who loves charts and graphs. But in this instance, it is of no use.

Also the coil is just a slave device and if it sound will have no impact on your timing or pinging, To check if it is sound you, will have to ohm it out.

 

Regarding the Bronco---Touch the black meter probe to the negative battery post, not to the negative post on the coil? Ok, I didn’t know that. So as you can tell, electrical is not my strength……LOL. So I did the test again and this time I touched the black meter probe to the negative battery post and the positive meter probe to the positive post on the coil and this time the reading was .66. Not sure what I’m doing wrong because I did what you said. Maybe my settings on the multi-meter are not correct? I set it the same as testing the battery. Look at the picture and tell me if the settings are correct. This is exactly how I had it set when I tested both the battery and the coil.

Regarding the truck---What you said about the pinging when loaded vs unloaded is what I’ve always experienced and come to understand and this is the exact reason I wanted to make sure I get this clarified 100% before I went ahead and adjusted the timing curve and then head out on my next camping trip towing my trailer and then lose the engine again. This is exactly what scares me with adjusting the timing curve to come in sooner.

So with that said, what is your opinion about leaving the black bushing in so it stops the mechanical advance at 36* (18* initial + 18* mechanical), but change the timing curve to be all in at 3000 rpm instead of 3500 rpm where it’s at now? Do you think I would have any issues with pinging under load towing my trailer? Would I gain any pulling power if I brought the curve in at 3000? FYI….I already use Conoco supreme gas w/no ethanol in my truck and I’m going to start using this same gas in my Bronco.

 

''Too may cooks spoil the broth'' as they say. I'm out.

 

Well you have your meter set to battery testing for one. You want it on the DC Volt setting just right of the OFF position at 1 O'clock. If you do not have the OP manual for your meter I suggest you go to the Innovas website, they should have it.
Oh hell here ya go .
https://csr.innova.com/Content/Manua...wnloadable.pdf


What happened to you before was a fluke and could happen to anyone. But there is having it come in earlier and having it all come in just off idle. Is what losing a spring could do.

You want your mech to advance all before 3000 rpm for a few reasons. It will take full advantage of the vac advance maximizing power and fuel efficiency at part throttle. It negates any chance of high RPM detonation (which is really destructive) and can be induced by the vac advance.. Think holes blown in pistons instead of just melted.

3000 RPM is actually considered late for full mech advance generally you want to see it all in by 2500-2800 RPM. But for trucks, it may be beneficial to push it back a bit to 3000 rpm.

And again not sure how many more times I need to say this, but need to get your mech all in before 3000rpm BEFORE doing anything else.

THEN you can adjust for your total. You are not going to have ANY idea what your total will be UNTIL you get the adavnce all in by 3000rpm.

And 18° base (initial) is way way too much, the max you should EVER run is 16° base and only if left no choice. Ideally you want to be in the 8-12° range. Also 36° total advance is going to be too much you likely are going to end up in the 32-34° range ONCE you get your mech all in by 3000 rpm.

So you need to get your mech advance in all by 300RPM "FIRST" THEN you can play with your total.

And again do this on regular fuel for the reasons previously noted and to reiterate. It will give you a buffer and allow the engine to operate on regular fuel or premium that is of say questionable quality.

Modern engine management control units can adjust parameters if they get batch a crap fuel your carb can't. And since you are NOT buying your fuel in pre-packaged 5-gallon cans or at a race track, you really have no idea what you are actually pumping into your tank from the local gas and go.
Did the tanker driver mix up reg premium at the distribution point?(it happens way more often than you think)
Did the refiner just get a bad batch?
Was reg used to flush premium piping after a shutdown and now the gas and go has mostly reg in their premium storage tanks?.
All of this can, does, and has happened, plus a pile more things that can lead to the local gas and go-getting a batch of crap premium.

So having a vehicle that actually tows and hauls and can ONLY run safely on premium fuel is an accident waiting to happen.

 

Matthewq4b--So the consensus between you, 6 by 8 and others is to get my mechanical timing all in no later than 3000 (and possibly earlier), regardless of what gas I’m using. I was in the process of working on this the other day when I went to change the heavy spring to the light spring when I discovered I already had a light spring installed (in the Bronco/400). So what I’m going to do is swap the other heavy spring to a medium (blue) spring so I’ll have a medium spring and a light spring. Then I’ll chart the timing curve and see what my timing comes in at. Then I’ll take it for a drive and see how it acts. Sound good? I’ll also get you guys the reading on the coil tonight, now that I know what setting to put my meter on. I guess the 3rd time is a charm. Thanks for your help with figuring out the settings on my meter.

It also sounds like I can safely adjust my mechanical timing in my truck/460 to come in earlier than it does now (which is 3500 rpm). 6 by 8 was saying he didn’t have any trouble towing heavy loads years ago with his timing coming in earlier so I’m going to, at the very least, swap a heavy spring and get it to come all in by 3000 rpm and see how it acts. I’m going to leave it there until after my camping trip in July, which is the next opportunity I will have to tow my trailer and see if I get any pinging. Just in case, to be on the safe side, I will bring the heavy spring I will be taking out with me on the trip just in case I get some pinging and need to swap the spring out. The setup I have now, I get no pinging pulling hills and the engine runs cool and I want the same results if I change springs. I have some pretty steep hills to pull (steeper than 6%) and it will be hot outside (July), so I want to be on the safe side. I’ve lost an engine once and I don’t want to do it again. But in the meantime, before my camping trip, I will do some highway runs at WOT and see what happens. My truck has a 4 speed with 5:13 gears so to do a WOT pull will be much easier if I can get it in 4th on the highway.

6 by 8—I know you and Matthewq4b have some conflicting info and differing opinions, but I am hoping you don’t bow out of this conversation. I’m learning a lot from everyone on here and your information is very valuable and very much appreciated. Thank you for all the help you’ve provided.

I am implementing both of your guys advice, but this has been a slow process due to having to work in between working on my Bronco. I’ve got several irons in the fire right now so I’m moving as fast as I can on this project. With all of your help, I’ll get this figured out.

 

Yes drop down the heavy spring down to a medium spring then check to see where the timing is all in at. You know your total is 18 and you are using the black bushing. The Black bushing gives you 18° of mech advance. I would swap it for the Green bushing this will give you 23° of mech advance.

You can then dial your base back to 8° and that will give you 31° of advance. Start from there on Reg fuel doing WOT runs to 3500 RPM on a hot engine from a rolling start.
Be sure the vac advance is disconnected when doing these runs.
Basically, you will let the vehicle idle in drive and roll along then mash the throttle to the floor and hold it there till the engine reaches 3500 rpm and listen for pinging while it does.
If you have no pinging on a run advance the dist one degree So your second run will be at 9° base 32° total. Third run at 10° base 33° total. etc etc. Keep doing this till you just get some pinging. Then back it off one degree. And do a WOT pull from a rolling start on one of the hills. And listen for pinging if you get light pinging your dist is set and you will be good to go on premium while pulling a load. Yes you are definitely leaving some performance off the table here no question, but the goal is to ensure your engine can survive while loaded and pulling a hill.
You can then verify this by pulling the hill with your trailer on a tank of premium. The same gig rolling start and pull the hill at WOT.
The rolling start is just there so you do not shock the drive line. form a standing start

Once the mech is dialed in you can set up your vac advance, all you want to be able to do is apply light throttle while at cruise/part throttle and have no pinning with the vac advance.

And you can not really use someones else build and expect your will behave the same in regards to timing. 2 identical engine builds will not behave the same unless they are installed in 2 identical vehicles and this includes things like weight and final drive ratios. All you can do is use similar builds to give you an idea of where things may end up.