A couple questions.....what's a quick advance kit? And what is the benefit of having your timing all in at 2000 rather than later, like 2500 or 3000? Just asking for educational purposes.

 

Oh yes, I remember when it was called "super" also. I didn't know that's what you were referring to.

As far as the 460, I can advance it more than 18*, but if I do then my max mechanical advance goes higher than 36*. So I put it at 18* based on not being able to limit my mechanical advance any lower.

Regarding the 400, max idle timing without pinging is 14* (probably because of the cheap gas I'm using). I can advance the mechanical timing more than it is now because after setting the idle timing down to 14*, now my mechanical timing is down to 32*. So should I bump the mechanical timing up to 34* or 36*?

And I have no idea what the answer to your question is regarding what advance I'm at before it pings because my total mechanical advance isn't all in until 3500. You guys are saying that 3500 is way too late and I should bring it in sooner by changing springs.....correct? With the Bronco 400 I can bring it in sooner without too much worry because I'm not towing with it. My only concern about bringing the timing in sooner on my 460 is will that make it ping when I'm pulling my trailer with the pedal on the floor wide open? If it won't ping in that scenario with the timing being all in at 3000, then I'm more than willing to swap springs and bring it in sooner. I'm just scared to because I lost an engine in the past and don't want it to happen again.

 

34-36 works fine on lots of engines. considering the octane issue it might be a bit much for you but it might not. if you're in the low 30's I'd run with it .

When I asked where it is when it stops pinging I mean what is your total timing when you check it after the test drive , this would be the most you can shoot for at the moment.

You could lighten the springs and get it in earlier to see what happens. probably it would be okay and if so it would get you a little better performance .

Detonation can occur without you hearing it so you're right to be concerned. but in all the years I've been using the peak method to set timing I've never had an problem, I just make sure I'm on the safe side of optimum .

 

Just an opinion here with all this topic at hand, however what brought my attention reading is the 9.5-10:1 CR on the new build -

Even with open chamber factory cast iron heads - just my opinion though I think you should also run premium grade pump gas as mentioned by 440 six pack regardless of the curve settings....

You really want the fuel inside every cylinder to cycle a 'complete burn' much faster for optimal performance while doing any higher compression engine a favor....

Sure there are other ways to tweak a high CR to run on regular pump gas with adjusting valve timing a little, ceramic coat chambers, run aluminum heads, adjust ignition timing and curve, etc. - however there is no substitute when it comes to a quicker fuel burn on any fresh engine gas running build past 9.0+ CR to optimize the POWERRRRRRRRR.

Back in 1988, I had a serious decision to make reference to my 1970 Thunderbird at 160,000 original miles as I fully committed to rebuilding the 429 in it, just how exactly was the dilemma -
- Continue to make it an everyday driver and get dished pistons for it and lower the compression which will still run pretty rad on pump gas
- Or not make it an everyday driver anymore while spending more money on obtaining another clunker 'affordable' vehicle (72 Dodge Dart - 225 L6) and make it an everyday driver running on pump gas and save money in the long run as I did all the math (a 10+ year commitment to pay for itself in comparison)

I estimated based on 15 MPG for the Dart, with the same yearly average expenses of parts and oil costs with the Thunderbird, as my T-Bird in the 5 years of ownership (1984-1988) prior to the engine rebuild was 11.47 mpg and cents per mile in that span was only like .2342c but that was still high in cost compared to other vehicles.....I got the Dodge Dart for free but had a hole in the block (#5 rod went thru it) and got lucky 2 years later when someone abandoned a 69 Dart in the lemon lot and the back seat had a complete torn down slant 6 engine in pieces waiting to be machined and I snagged the entire engine before they impounded the car to the junkyard and got an estimate of $1200 total cost for a new running slant 6 engine (with premium parts and extensive machine work)...

So committing to an extra $1200 for basically a new car plus saving an estimate 3.5 MPG on pump gas was the base for not making my 70 Thunderbird an everyday driver anymore (and turned out I would have broken the break even point in just 7.5 years rather than 10+ years in total cost) as I exceeded my expectations with the Dart in the comparison when I averaged 16.72 MPG from 1992 thru 2016.

Here was the serious decision I eventually committed to over the 429 by NOT making it an everyday driver anymore with a fresh rebuild :
- I got D0VE-C Heads that are 72cc CLOSED CHAMBERED !!!!! (and REALLY wanted to utilize them to the fullest)
- I really wanted to commit to TRW FORGED Flattops (11:1 CR) and did so (L2366) x 8 each
- Idle-5500 rated 270-280 advertised duration RV cam
- However I fully committed to suck it up and run at least 50% 100 octane low lead AVGAS which was going to be much more expensive.....
- Only two places I can purchase the 100 Octane AVGAS is airports or bulk plants - and neither place will allow to dispense fuel from the gas pump, so it was fill up the jerry cans (6 containers in the trunk that hold 32 gallons) and dispense yourself.

Well, I tried the 50% mix method and it still did not perform as well especially driving on hot days and driving up significant grades.... kept pinging, and or pre-detonation no matter how I adjusted ignition timing to try to find that optimal area.

I really sucked it up and finally fully committed to running straight 100 octane instead - which gave me an additional 1.2 MPG increase while all the pinging and pre-detonation was FULLY ELIMINATED. (13.6 to 14.7 MPG range straight 100 octane) vs 12.3 to 13.4 MPG range running 50 pct premium pump gas)
....and at one period when pump gas and 100 Octane AVGAS was only a .59c price difference per US Gallon, my cents per mile by running straight AVGAS was actually LOWER than running 50 percent pump gas bar none as those days are now long gone !

I have yet ever had anyone pass me going uphill on any 6% to 11% grade since running straight 100 Octane AVGAS as it just holds the power (4 BTDC with 4 degree crank advance), and my car is 5390 lbs with fuel tank full...still runs remarkably smooth at 113,000+ rebuilt miles.

I also learned that 100 Octane fuel burns 0.03 seconds faster than pump gas designed for lower compression vehicles.

Had a young kid walk up to my 70 Thunderbird and asked me if I ran AVGAS in it and I asked him why did he think I would do such a thing, as he replied because your car smells just like my dad's airplane !

When I rebuilt my 1970 390 Ford engine in 2006, I committed to 8.6:1 CR to run on 87 octane pump gas with hardened exhaust valve seats...
...and committed with 8.4:1 CR when I rebuilt my 1973 460 in 2010 to run on 87 octane pump gas as well - I did not want to commit to an extra .30c per gallon cost in fuel comparison if wanting over 9:1 CR for an everyday driver or occasional winter emergency vehicle as cold as it gets in my area.... there is a lot of engine idling to keep warm during sub zero temps and these powerplant big block engines are not designed for fuel mileage anyway - and wintertime there is even less fuel mileage so that's why I committed to the mid 8's CR on these two rebuilds - my math told me it was not economically viable in the long run to pay 10% to 20% extra for premium fuel with a higher CR as my yearly local commuting gasoline costs for all vehicles the past 5 years range between $3200 to $3600 (and that is without any extensive out of town regional traveling).

Like I first mentioned, this is just an opinion upon a extensive perspective as I account for every cent for fuel and parts in each of my vehicles that I own since 1985 and keep on file, and personally just feel in my experience with any higher compression gas engine is to run a higher octane fuel that is optimal enough and designed for that particular compression range - and commit to pay extra fuel cost for it.






,

 

If your engine was previously 8.5, say, and it's now at 9.5, you'd want a cooler spark plug. One down in the heat range.

You haven't mentioned the actual timing curve.

If you plot the timing readings on a graph at 500rpm intervals, and connect the dots from 14* to 32*, the line should be linear. (Like on the MSD instructions.)

If so, you can trust the dizzy.

When you change springs, you can plot the curve again, so you can see what change the springs made.

Total timing of +/- 34* to 36* was the basis for the OE spec engines.

Your engine with a higher CR, assuming the internal goodies were spec'd to increase efficiency, would require less than 34* to 36*.

 

AKsilvereagle—You make a valid point for using higher octane gas vs lower octane after. Reading your detailed explanation….thank you for that by the way….I might just commit to using supreme fuel for reasons you explained. Another reason I might commit to using it is this: in my experience with my 460, I get 3 mpg better fuel mileage using the Conoco supreme with no ethanol (91 octane) than I do with the cheap gas (87 octane) that has ethanol. And you’re right; the supreme performs better than the cheap stuff. And here’s one of the biggest reason….the ethanol eats rubber lines and gasket material.

Honestly, I think I just experienced the evil of ethanol just this week (but the jury is still out because I haven’t got the replacement part yet). When I rebuilt the 400 in my Bronco, I put an electric fuel pump on it with a Holley fuel pressure regulator. Well just the other day I just happened to notice my fuel pressure gauge was reading 3 psi instead of the 5.5 psi where I had it set. So I tried to adjust the fuel pressure higher and it would not go higher. And on top of that the fuel pressure was dropping as it was running. And on top of that, when I shut off the engine the fuel would completely drain out of my fuel filter in a matter of a minute or two. I am only assuming that maybe the diaphragm went bad in the fuel pressure regulator and isn’t holding pressure???? If this is the case, I’m willing to bet the ethanol in the gas destroyed the diaphragm in the regulator. So I ordered a new diaphragm ($8) and it will be here Friday. When I get it installed, it will give me the answer. The point is…with our experience with cheap gas vs supreme gas, I know you’re right about using the better gas. It’s just hard to pay higher prices for gas that is only expected to skyrocket higher (right now supreme is $4.09 per gallon and expected to go higher). But when I sit back and think about it and take into consideration everyone’s comments advocating for using the supreme gas, I’d probably be saving money in the long run by using the more expensive gas and have less mechanical issues…..Ok, with that said, I think you (and everyone else) convinced me…..LOL.

So if I start using the supreme gas, I assume I can probably advance my idle timing back up to 18* or somewhere in that neighborhood without pinging issues???

6 by 8—I’m using the Autolite 25 spark plugs. Is that a factory heat range plug? If not, which Autolite plug would be one heat range colder?

I don’t know what the timing curve is because I didn’t check it at 500 rpm intervals. When I was setting up the timing on the distributor, I was focused on total mechanical timing so I logged the timing at 3000 rpms and higher so I could figure out which bushing and springs to use. I supposed I need to check total curve. I don’t have a dial back timing light (nor do I know how to use one), so I had my son sit in the driver’s seat and rev the engine to the desired rpms by watching the tach.

So do I understand you correctly that you’re advising to keep it at 32* mechanical timing because I have higher compression pistons? Am I correct to assume that higher compression engines don’t react well 34*- 36* of timing???? Can you elaborate?

 

High compression engines can run great on 36 , but only if the required octane is used.

Your32 is probably fine, I'd run it a bit and see. ignition timing is an exact science but there are way too many variables to put exact numbers on it without experimenting. you'll probably never get it perfect, neither did the factory.

 

Time to do your timing curve !!

Be patient with your son, and ask him to hold the rpms steady at 1,000, then 1,500 etc up to 3,500. (3,500rpms at present)

It takes a bit of practice, but once he has rpms steady, he can give you a thumbs up while keeping his eye on the tach.

Basically, good communication between the two of you will make it a quick 'n easy task.

The starting point on your graph will be the timing number at the idle rpms.

Ensure no vacuum advance is connected during this time, and make sure it is plugged.

If your son is smart, he will ask you for a bribe prior to helping you. LOL

If the curve is not linear, then there's a good chance that the dizzy is faulty and needs to be returned.

If it is linear, you can then focus on idle and all in timing settings, and the speed with which timing comes in.

A faulty dizzy can advance timing way too quickly, or not really advance at all, so it's best to ascertain the curve accurately initially.

You said you don't get pinging at 14* idle, but you do at 18* idle.
I assume that's 32* and 36* respectively.
No comment on that until your timing curve is confirmed to be working correctly.

I also assume that your pinging was observed at W.O.T.
W.O.T. drops vacuum to zero so it wouldn't matter if ported or manifold vacuum advance was connected.

If your pinging was at partial throttle, rather test at W.O.T. first.

With regard to running a total timing of 32* (ignoring vacuum advanced timing), I meant that it depends on the engine.

A modern OE V8 can run at as low as 24*, (ignoring computers) and that's because of the combustion chamber shape, deck height, cam choice, etc.

Basically, the better combustion efficiency requires less timing.

If your higher compression pistons created a zero deck height, and assuming the cam specs work with the new setup, then yes, you could stay at 32* instead of 36*, say, because the combustion would be more efficient.

I hope that makes sense.

'Too hot' spark plugs, a lean gas mix, can cause pinging too, just for info.

Wow !! Was a broken dizzy spring really the cause of three destroyed pistons ?

If it really was too much advance, then the noise of the pinging should have awakened the dead !!

(I wanted to say that either your truck is seriously incredibly loud, or that you're deaf (LOL). But I won't say it.)

What's the part number of your existing MSD dizzy, and what coil is in the engine ?

With regard to 87 versus 91 octane, my highly mechanical technical comment is this : I'd rather push my truck than feed it 'cheap gas'.

The higher octane level would definitely allow you to return to 18/36 timing.

I'll look up the Autolites later.

 

Read the tips of your 25's and see if they are too hot or too cold or close enough.

If too hot, try Autolite 24's.

Then read those tips, and if still too hot, try 23's.

 

If the fuel and engine will tolerate it, the earlier centrifugal timing gives a little low rpm torque boost. The kits used to be popular, featured weaker springs and some included heavier weights. I put mine in and while I said all in by 2,000, if memory serves me correctly, it's all in earlier, but I just make sure I'm checking timing total above 2,000 as by then, more rpm does not increase advance on the marks. I also do not even check timing at idle as the weaker springs and heavier weights and I recall limiters that decrease the range of timing change with the centrifugal advance, so even at idle, there's some extra advance in it and OEM book specs are meaningless. My balancer is scribe marked up to about 50* now. When I installed the kit 30+ yrs ago, I would tweak, then try it out to check for preignition, then tweak more. It might take more but I'm happy where it is.

Example:

Distributor Advance HEI Curve Kit BK 7354448 | Buy Online - NAPA Auto Parts (napaonline.com)

When setting, adjusting timing the vacuum advance is disabled, it's only intended for light throttle light load cruising. If there is a pinging at part throttle that goes away with a heavier foot, there are vacuum cans that you can adjust some vacuum advance out of.

 

440 Sixpack—I think you guys have convinced me to run supreme with no ethanol from now on. I get better mileage, better performance, more timing, and there’s no ethanol to destroy parts. It’s more expensive up front to pay for the higher cost of gas, but in the long run it’s cheaper. I guess it just took you guys to talk some logic to me that I already knew.

6 by 8—Sounds like creating a timing curve chart would be very informative. Seems simple enough to do. I will have to work on getting that done. And my son asking for a bribe would just backfire in his face, and he knows it. But I’m sure it won’t stop him from trying…..LOL.

I get pinging at part throttle with the idle timing set any higher than 14*. And yes you are correct; 32* & 36* respectively.

Regarding the plugs and lean gas mix causing pinging…..I haven’t pulled the plugs yet after the rebuild to inspect them. Still need to do that. But I was running an Edelbrock 750 on it up until a couple days ago when I swapped it out for an Edelbrock 600 that I took off one of my 67 Cougars. So now that I have the smaller carb on there, I need to start over with reading the plugs. But maybe it will still give me a clue as to whether the plugs are too hot or not even though I changed carbs. And when I install the headers, I’m going to buy a dual Air/Fuel gauge and have an O2 sensor in each header so I can more accurately monitor the a/f mixture. I’m hoping to do that next month. Gotta save the money for the gauge and new mufflers.

Yes, a broken spring allowed the distributor to advance way too much and it melted my pistons because of the timing. This was confirmed when I sent the distributor back to the engine builder I purchased it from who did the recurve. When he tore it apart he found the broken spring. So a .10 cent spring caused a couple thousand dollars of damage. That should tell you how my luck goes. If it wasn’t for bad luck, I wouldn’t have any luck at all…LOL.

Yes my truck is kinda loud. It’s a 78 and all the door and window seals need replaced so you can imaging the wind noise I get. And on top of that I have exhaust/muffler noise and whatever else. So yeah, it’s hard to hear the engine over all the noise going on. Having a conversation with my wife in the truck is challenging because we have to talk loud just to hear each other. So it’s kind of a deterrent for conversations. But I won’t say that could be a blessing in disguise…..LOL

The distributor in the Bronco is a MSD 8477 and the distributor in the truck is 84771. The only difference is the distributor in the truck has a bronze cam gear because of the roller cam, hence the 1 at the end of the part number. The coil on both engines is a MSD Blaster 2.

Thanks for the Autolite plug numbers. I will definitely monitor the plugs.

Tbear853—So that quick advance kit seems to be the same thing as the bushing and spring kit that came with my MSD distributor. I didn’t realize that’s what it was called. And I always set timing with the vacuum advance disconnected. And I haven’t put my foot into it when I hear the pinging. I always back off because I don’t want to damage the engine.

 

If you're pinging at part throttle your vacuum advance might be pulling in too much . be sure you have it on the ported fitting.

Pinging at normal speeds isn't as devastating as it is under WOT but over time it will take it's toll.

 

It's on the ported fitting. I've never run it on the manifold vacuum fitting. It doesn't ping at part throttle with the timing set at 14*, just anything higher.

 

You're a braver man than me for putting that in writing ! LOL

If she ever reads that, she knows exactly who ''78 Ford F150 460'' is, and you could be in sh$t.

Now, in case she gets angry with ''6 by 8'' for laughing, my name is Mary-ann, I am 93 years old with long white hair and a beard, and I live in Antartica with my Mum.

Now that I've guaranteed my safety and well-being I feel safe to stay in your thread.

In fact, I feel so safe now, I'm happy to share a tip with you.

One of these days your truck will be nice 'n quiet in the cab, and you know what that means.

So, you could sit Mrs 78 Ford F150 460 in the back on the bed !

I know that sounds mean, but it isn't if you supply a cushion and a book to read.

However, there are considerations.

If you have a rear sliding window, she must sit on the driver's side.

Why ?

Coz it's a nuisance to turn the whole body to talk to you compared to the passenger side.

If the rear window is solid, ok, she could sit on the passenger side, but!, you run the risk of being glared at, but only if the book is crap or it's raining. (Or you forgot the cushion.)

Never sit her in the middle if you have decals, as this messes with the HP mojo, assuming the decals have been fitted correctly (I.E. centred)

Oops, nearly forgot, always keep your window closed when she is sitting behind you.

I got punched once and it scared the crap out of me.

I was going to say have a heart and give your son $10 for trying, but seeing as you're upgrading to premium, $1 would be fine.

Ok, with regard to the timing, carb, gas, plugs etc.

Change only one thing at a time, and only move onto the next change when you're happy with the change you just made.

Driving around after one change, and 'feeling' the difference, will assist your learning.

No comment about the timing until you've posted up your timing curve numbers.

At partial throttle, both manifold and ported timing should be the same, so no worries there.

When you get the chance, measure the voltage at the battery terminals when the engine is warmed up and running.

You should see +/- 14 volts.

Then measure the voltage at the coil terminals. You should see +/- what you saw at the battery.

If you see only +/- 12 volts, and the battery was +/- 14 volts, then you have to replace the OE ignition 'resistor' wire with normal wire.

With regard to the weight of your truck, it should not have any bearing on your ignition timing and pinging.

 

At part throttle, you are on the vacuum advance that is what is causing your detonation, too much vac advance.

Disconnect your vac advance and set up your mech first, And 32° with your build is pretty conservative.

14° base is really about as much as you want to run. Ideally, you should dial that back and increase the available mech advance. Also you want your total mech all in no later than 3000 rpm.

So increase your total available and dial in by advancing it till you get pinging on full throttle then back it off 2 or 3° (this is done with the vac advance disconnected) shoot for a base of 6-12° by adjusting your available mech.

Then you can dial in your vac advance.

Also, manifold vac is exactly the same as ported except at idle, where ported should have no vacuum signal.