Hi everyone. I would like to post this information. I did something to my vacuumn advance module many years ago and I want to share it with you. This may astound you. As you know the vacumn advance mechancism means exactly what it says, it advances the timing.

I cut a notch on the opposite side of the factory vacumn slot of the distributor housing and installed the assembly on the opposite side of the housing.

Now when vacumn is applied to the newely positioned vacumn canister the timing is retarded. So when your climbing those big hills pulling alot of weight you don't hear those "tin-cans" rolling around under your hood and you will see the water temp drop.

I controlled the vacumn retard by a simple device you find at your local fish store. The clear plastic hoses for the filters and the brass valves they sell work just fine.

I rerouted the new lines to the dash for controlling the vacumn retard. A simple turn of the valve and you will hear those "tin-cans" disappear entirely.

I would like some feedback on this. I did make this and it does work.
Thanks. Ed.


http://www.camaros.net/showroom/data/500/at.jpg

From advice of my friend in the ignition system business, I mounted a "vacuum advance" from a turbo Buick, dual sensing. Then, the one hose from the front to full manifold vacuum, the other one, on the back, to ported vacuum. Now, the "advance" works as it should for acceleration, and retards the timing for severe loading, like pulling up a steep hill. No valves, no other cutting, no rattling, just bolt on, plumb, drive it.

And, lets call a "vacuum advance" what its real name is, it is a "load compensation device", (this is exactly why Ford called their early vacuum timed only distributors 'Load-A-Matic"). Yes, it is vacuum operated, yes, it changes the ignition timing, but, it is there to compensate for different loading of the engine, both for acceleration and constant rpm operation. Turbo load compensation devices have the ability to also retard timing for excessive loading as the turbo increases compression ratio on boost.

If yo hang around my friend long enough, you get a real world, full on education on how these things work, the right way.

Regards,

Milton

How do you release the vacuum from the can under normal driving conditions?

First let me welcome you to the site and commend you on your creativity, craftsmanship and having the ingenuity to make the modifications you describe. At that since you are asking for feedback, here's my .02...

I don't understand the need to vacuum retard the engine timing if the engine is properly tuned and timed to begin with, at least not in a street driven application. As I understand it manifold vacuum decreases when an engine is under heavy load such as taking off from a stop or pulling the car up a hill. It's only under light load when the throttle blades are near closed that manifold vacuum increases. Having a vacuum retard seems to be counter intuitive under those conditions. Maybe there is something I am missing...

No offense, but that design is totally backwards of what you actually WANT and NEED vacuum advance for. Your setup will advance the timing as vacuum decreases (IE pulling a load up a hill, accelerating, etc), and retard the timing when you are in a high vacuum situation (cruising, idling, etc). I would suspect that an engine setup this way would detonate its guts out pretty quickly in something like a truck, not to mention fuel economy would decrease considerably.

Hi everyone. I would like the opportunity to explain more on this concept I developed in the mid-seventys. Detonation can be a troublesome problem especially if you have a loud exhaust..."you can't hear the pinging". Back then it was nothing to have a car with a 10.5 to 1 compression ratio, but now its different these days.

Basically what I did was to feed the engine with as much inital timing it would take...until it failed to turn over, then I would back it down. I changed the springs and weights on the mechanical advance also to ..lighter springs and heaver weights.

A stop can be incorporated on the plate with a fine thread bolt mounted in the housing looking somewhat like this...---> L.... the arrow represents the fine thread bolt and the L reprensents a soldered bracket on the point-condenser plate...I left that part out of the drawing. With this fine adjustment you can "limit" how much play or distance the plate turns. The fine thread bolt has 2 nuts to lock it down.

You want a some ping once and a while when your under load but, not a constant ping.

Also using the same principal I was able to create a water injection system using a container filled with 60% alcohol 40% water. The tube was attached at the bottom of the can and was routed to the dash with the brass valve and back to the carb vacumn fitting. Whenever climbing a hill under a load,.. I released the valve and the mixture was applied.

Also I did this with the vacumn modulator on the tranny.

Reply to travis...You said.."Your setup will advance the timing as vacuum decreases"... If I get what your saying it will not advance the timing because when you turn on the valve the plate turns clockwise thus retarding the timing.

Reply to DJD...Thank you for allowing me to post my drawing and thoughts.

Replying to onovakind67..."How do you release the vacuum from the can under normal driving conditions?"..A turn of the valve which is mounted in the dash feeds vacumn to the dashpot.

Reply to The Devil's advocate.."If yo hang around my friend long enough, you get a real world, full on education on how these things work, the right way".

Tell your friend to log on and take a look.

Ed.

Replying to onovakind67..."How do you release the vacuum from the can under normal driving conditions?"..A turn of the valve which is mounted in the dash feeds vacumn to the dashpot.


What if there's high vacuum on the valve? How do you get low vacuum to the valve?

Along the lines of DJD..
I don't understand the need to vacuum retard the engine timing if the engine is properly tuned and timed to begin with.......Having a vacuum retard seems to be counter intuitive under those conditionsIt sound very much that the cent curve and total cent + intial is mis matched to the engine requirements, then compensated by moving the advance plate.

The total, intial cent hast to b tuned in before the vac advance is tuned in oir even considered. using a device to compensate a curve that is wrong in the 1st place can in the long term do serious damage to the engine.

He has already seen it, doesn't post here. He did this years ago, back in the very late 1960's, I asked him about an hour ago.

If, in fact, the curves are correct for the engine, you shouldn't need timing retarding. I only do the retard on the 2 tow vehicles I have to help with heating and the POSSIBILITY of detonation. With a stock type single stage cannister, I never had problems in the first place, and would think I still won't.

My friend, Dave Ray (IgnitionMan) says,

"Retarding the timing in an every day situation is only for those who can't seem to get the timing curves right in the first place, or, those who insist on listening to both those who just don't know, or, insist on using ported vacuum control for the load compensator. Except for those very heavy tow vehicles that are lugging a really large load up the Grapevine or other very steep grade, a timing retard isn't needed unless the compression ratio is being pumped up by blower, turbo or nitrous use".

Now, as far as I am concerned, he knows one heck of a lot more than others have shown, and has proven it to me, and a lot of others on this, and other boards, and, in his conversions. They work, and as far as I am aware, they don't use a retard feature for the vacuum advance. I know Dave to be the kind of person to cut and weld things together, like one distributor that fits a certain engine, with a different top on it from another engine, so one ignition system will fit, instead of just saying "it can't be done". I have been in his shop when he has done his Doctor Frankenstein act, making two into one, and they just plain work, correctly. All 26 of my Dave's conversions work perfectly, and the only two vehicles I have with the retard vacuum advance, are large cap HEI equipped.

Regards,

Milton

You want a some ping once and a while when your under load but, not a constant ping.



Please explain :confused:

Even with a moderately quiet exhaust system, if you are hearing some pinging then there is a bunch of pinging that you aren't hearing. Reading the plugs is the best way to determine this, as you will see "peppering" on the plugs porcelin.

My other concern with this design is that you have eliminated any "normal operating mode" vacuum advance, thus eliminating the fuel economy and driveability benefits that normal vacuum advance offers.

If I am understanding you correctly, essentially what you are doing is having the engine operate "normally" with a high amount of initial advance and mechanical advance, and then you activate the vacuum retard function as needed? It still seems to me like an overly complicated way of compensating for something.
I primarily build truck engines, or engines for heavy, highway geared cars, and many times these engines are used to haul heavy loads, and have NEVER had issues with these engines overheating or pinging even when towing as much as 9500 pounds, and their "unloaded" performance is WAY better than stock. With the correct timing curve and a properly working (and set up) vacuum advance system, assuming your engine components aren't horribly mismatched, there shouldn't be issues there.

Hi everyone thank you for replying to my post. I would like to draw your attention to what I stated before.....

"when your climbing those big hills pulling alot of weight you don't hear those "tin-cans" rolling around under your hood and you will see the water temp drop."

I'm only pointing out that weight can and will cause a strain on the motor detonation will occur even with full throtle applied to a stock distributer pulling no if any vacumn on the dashpot that results in a "factory retard setting". Vacumn drops at full throttle in the inlet of the orface tube plugged into the distributer and the advance plate moves clockwise to retard timing.."factory setting." Using a vacumn dashpot on the opposite side of the housing gives more controllable adjustment with a stop in place.

Prolonged heat is the culprit to detonaton. Intake and exhaust valves run much hotter and if there's any carbon deposits on them or in the combustion chamber you will have preignition. Water and oil temperatures rise as detonation occurs.

I know you think you have no problems with detonation because you know the engine runs fine by checking plugs and tearing it down but, it does happen. Loud exhaust prohibit you from hearing the pinging.


Thank you very much everyone.

Ed.

I don't have any problem with your theory, I've driven far too many overloaded gasoline engine service trucks all over the US and I KNOW what you are talking about. There is no "curve" that will compensate for lugging 12,000# with a 200HP engine.

The thing I have a problem with is how you are GETTING VACUUM, because you are in a wide open throttle condition(or I always am) and you wouldn't have the vac to pull the plate with. Your canister must have a weak spring huh? Like a 2 or 3" HG one. And then like onovakind asks, how are you disengaging the vac? Do you use a 3-way valve?

Good question Tim. The vacumn you speak of exhist above or near the air-horn. Thats always prevelent. It is possible to arrange a line in that location. At full throttle you can bet there's enough suction in that area to gobble-up 50 distributer vacumn modules.....Anyways Tim I did make this in the seventys along with the water injection system using the clear plastic tubing and brass valve as shown on the drawing.

Everyone... I know this drawing is a differen't way to business. I also know that the boys in Detroit don't care because they have the patents on most everything you can come up with. Its up to you here on this site to prove to Detroit we mean "business".

Thank you
Ed.

Ed - This is an interesting subject, now that you have introduced us to vacuum retard and your version of how to do it, can you provide how it might help a classic Camaro owner? You will rarely hear of an old classic being loaded down with a trailer and climbing the mountain (with the exception of Steps but he's not running gas either). We all know with high compression engines you can take a couple degrees of advance out of the equation to make up for fuel quality but that results in less performance.

I also did a little googling and vacuum retard was used in the 70's by some manufactures as a polution control to lower NOx emissions. The result was poor fuel economy, less performance and higher engine temps.

I also did a little googling and vacuum retard was used in the 70's by some manufactures as a polution control to lower NOx emissions. The result was poor fuel economy, less performance and higher engine temps.


Exactly the point I was trying to make, in a round about way. Retarded timing results in higher engine temps, reduced fuel economy, and reduced power under normal driving conditions. But, under normal low vac situations (IE towing, accelerating, etc), your timing is going to be retarded with a "normal" vac advance setup. With your setup, and running the very high initial timing needed for decent cruise fuel economy, you are looking at an engine that is going to be harder than normal to start (and hard on starters and flywheels), and be more prone to detonation under normal driving conditions, unless you are tweaking on this valve all the time.
I am not trying to bust your balls here, and maybe I am not completely understanding how your system could possibly work better than the "standard" vac advance setup. What I am offering is my opinions, for what they are worth, based on 20+ years of building and tuning experience. I also don't understand your comment "Its up to you here on this site to prove to Detroit we mean "business".". Detroit hasn't used vac advance distributors on anything in, what, about 20 years?
I am all for thinking "outside the box", and I may be all wrong and your design works like a champ. I am just not seeing it.

For the record, my folks had a '77 model full sized motor home with a thermoquad equipped 440 dodge engine in it. I went on a trip with them one time and I swear I was just waiting for large chunks of engine pieces to come flying out from under it. That thing pinged and rattled more than any engine I have ever heard in my life. I just cringed every time we hit a mountain road, just waiting to be stranded with a blown engine out in the middle of nowhere. We retarded the timing from 8* initial down to 4* BTDC, and while it did lessen the pinging it also made the engine run about 20* hotter, and really killed what power that engine had, as well as dropped "flat road" fuel economy from 7mpg to 5mpg. This was with just a 4* timing change!

I spoke with Dave last evening, after all the web stuff I normally do. He has done this many years ago, with somewhat dismal results. He did it a bit different, and in two stages, being the tinkerer he is. It also gave me a bit of time to think abouit how both my engines run while in the retard stage.

First stage, Dave cut a Chevy top off a Chevy distributor and grafted a Pontiac top to the Chevy post, installed the Chevy guts and shaft. This gave him the left turn vacuum advance mount and the right turn internals. He said the result was loss of power and economy from the loss of the vacuum advance NOT being there, and, overheating, general loss of drive-ability and fuel economy with the retard engaged.

Second stage, he did the same with a Chevy post, and built his own top from billit aluminum, and mounted TWO vacuum advances, one in the right turn position, the other in a modified left turn position so they both wouldn't conflict with each other. This worked much better, because it had the correct right turn vacuum advance, but, the retard section results were the same as stage 1. He found the best thing to do was just leave the retard diaphragm disconnected.

Then, when I first met him, I described the pulling issues I had with both my vehicles, and he got the idea for the turbo advance, and, only adding no more than 4 crankshaft degrees of retard, no more. The retard section was much better, but when in that mode, the temp still went up too much, and drive-ability went bad. He restricted both my retard turbo advances to give only 2 degrees of retard, and they work, but you can just watch the temp go up when the engine is using the retard, and the pulling power doesn't increase, it just stays where the retard engages. Even now, all the retard seems to do is make the engine hotter, stop acceleration, and severely decrease the fuel efficiency.

Now, I tow either a closed trailer with a lot of fun toys in it, or a nice ski boat with that 454 powered motor home, or the 502 powered C20 box van, and if I had it to do all over again, I would go with any Chevy big block EFI engine that wasn't an arm and a leg in price. These two engines may well get Commander 950 systems on them, which will remove the stock carbs and ignitions anyway. I still run the turbo cans, they are now only slightly irritating, but I don't see the real need in the first place, Dave didn't think they were needed in the first place, but I read a lot and got paranoid about pinging and detonation. Still, an interesting experiment it was.

That's just what he, and I found with the retarding experiments.

Regards,

Milton

Good morning everyone. Thank you for your time dealing with me. I would like to say...

"If" I fed the initial timing 20 degrees and "If" I fed the mechanical advance another 25 degrees a total of 45 degrees would be achieved at the determinded rpm range when the weights fully extend.

Now 45 degrees total is too much... SO I adjusted the "stop bolt" on the point condenser plate for a total of 38 degrees or more depending on the fuel, air temperture, humidity, altitude, and engine temperture so the detonation, pinging disappeared.

Also the water injection I spoke of was a big big help. It was developed by the Germans before anyone of us were born.

Ed.

45* under cruising conditions is not too much...actually it may not be enough as many engines get best fuel economy with as much as 50-55* total including the vacuum advance. Then, when the need arises, you press down on the gas peddle, vacuum decreases, and a normal vac advance system will loose some or all of it's vac advance, putting the total timing at a more appropriate position for the conditions at hand.
It sounds like you are attempting to accomplish the same thing, but in a more complicated way that also requires driver input adjusting timing stops and knobs and such constantly as driving conditions change, plus your still not going to get the fuel economy improvements that vac advance normally offers.

Another problem with 20* initial timing is that unless you have a pretty good sized performance cam in your engine and relatively low compression, your simply going to have too much total timing at low speeds. Some engines are ok with this much initial (many 307 olds engines came with as much as 22* initial from the factory), but in my experience most are not...stock or modified.

Hi everyone:..Thank you for your posts and your thoughts.

The timing retard system "in full advance" works hand in hand with what I posted here with the water injection system.

I've had that information to share since the seventys and NOW is the time to share that information here, on this site.

Thank you camarosdot net!

Its a long story that you may find very interesting but, I will be brief.

Just ask me and I will give you my best thoughts why this "maybe important" to you .

Thank you webmaster and everyone..

You will rarely hear of an old classic being loaded down with a trailer and climbing the mountain (with the exception of Steps but he's not running gas either).
Yep...I had a big learning curve back in the mid 80s...started with stock engine, then the rebuilt engine is hi compression (just under 11:1) low duration, hi com mentioned above.
messed with retard vac canisters welded to modified stems, hooking vac switches into the canister lines and solenoids manually activated and off trans...
They worked...but everything was a compensation for root issues
Then went to modding the dizzy interails, total curve, rate, and fully customised vac advance ..vac range and total degs

For tools used dynos, in car Co , Co2, o2, nox anylisers..
This was before the days of the 'net and info was all hard copy and hard to come by, so most of it was seat of the pants, what if? over a couple yrs
1/2 why thru, was also working on a dirt track sb..rooky driver...which by the end od the season took out Nth Island and Sth Island champs and 3 rd national champs.

What it all boiled down to is establish the correct cent curve/total working from the top ....all in rpm and total advance...and work backwards down thru the rpm range.
The cent curve established is under full load
To much advance causes hi NOx, and heat, ping, and slight drop off in power
to little advance high O2 and quick drop off in power..regardles of fuel type.
Then Knowing the charactoristics of the engine advance under cruise and light load and vaccuum at different loads one can the establish total intial+cent+vac advance...then map the vac range of the canister, and the deg range in the vac advance arm...and where in the arm it is....ie at what load the canister spring is at.

Compensating with retard mechamisms under load does work to sort out a major issue like dentonation or heat...but at the end of the day, u are putting a plaster on an other area that is not working correct and ...patching.

From here, I now take vintage engines, designed to work on old British pool fuels (Pre war to 1954,) and very low compressions, redesign/re curve to run on modern fuels, as they would have out of the factory...this includes comparisons by using reformulated fuels back to the old octane ratings.
Over 20 yrs not only have I been on SB camaro, but track, vintage and fuels ranging from 62 octane upto 120+ both liquid and gasious, and compressions from 5.8:1 to 11:1
and from Square cams (no duration/overlap) to around 290 degs