Oval Track Dizzy… Locked Advance or Not?

[Krooser]

I also asked this same question at a circle track forum. One member there posted this answer to my question… very tuff to read and understand but….

"After using a vacuum advance and only the best spring controlled weights to aid in hooking up with less horses for a few feet in order to be able to floor the car while sideways and it moving, I addressed the potential of hotter fire and more fuel! While burning twice the fuel that most use all night just in a 20 lap race with the plugs still snow white, I figured out that hotter fire allows for a boost in horses if you can put enough fuel in to match! Sure we wasted a few parts getting to that point but the horses was out of the gate! You can't turn back after being hooked and everyone is looking for the Nitrous on the car! Intakes were pulled! Fuels were sent off for testing! Tachs were disconnected! A stock GM module and coil with a tan cap and rotor that puts out more than you can believe! More than we could buy! A 10 degrees block on both vacuum and weights giving a 20 degrees advance total was used! Bench testing on 12 volts it would jump from pin to pin with out any plug wires on the cap easily! Test yours and it most likely just clicks inside or jumps to ground at the coil! Getting it to the plugs does require a good set of tan parts and wires to say the least! A Rocket 350 GM OLDS coil from a early year with a .080 plug gap was used! Jets must be changed before hot lapping and a constant check on the wet oil of at-least 3 threads on number 3 cylinder to keep from going lean and melting plugs, head gaskets or burning the block and heads in three laps! Proceed with caution as not to be shocked or trampled in the process of these extra horses! Set the timing with the engine at 5,000 rpms without vacuum hooked up! Be sure to use a live vacuum port or it will not fall back to the weights while on the throttle! I run no power valve in my carbs ( blocked and up 5 jet sizes more, 83-86s on a two barrel) and a cool 150 degrees engine temps to allow more air to flow as well! Work your way up on timing and fuel to get more horses with the extra fire power! No racing fuel used, just 93 pump gas! Hope you find more than you expected and then some!"

Read more: http://thedirtforum.boards.net/thread/4 ... z2yxY8L4sf

It took about 12 reads to understand what this guy was saying. I THINK I have it right…

He sez run 20 degrees initial… with 10 more vacuum and another 10 in the mechanical advance. Lots of fuel… 83-86 jets in a 4412 with the PV blocked. 150 degree water temp. The theory here, if I have it right, is to use the vacuum advance as a sort of 'traction control' keeping the engine down on power until the final 10 degrees of adv. comes in near the end of the straightaway… keeps the driver from blowing off the tires on a slick track.

Plus he advocates using the high voltage coil (Olds 260?)…

Has anyone used a 5 pin HEI module and used the 'r' terminal switched to ground for a 10 degree retard for easier starting?

Interesting stuff...

[Tuner]

I thought I was posting in English but it must be coming up on some browsers in ancient Sanskrit.

Having the correct mechanical curve is not about “reducing power so a (poor) driver can flatfoot the throttle on a slick track”, a good driver controls the power with his right foot.

The correct ignition curve maximizes efficiency and makes maximum power available at all engine RPM.

The correct vacuum advance only adds additional timing when the engine is at very light load, like on yellow flag laps.

Engines need more timing when they are at light load.

The correct timing at any load, WOT or in yellow, makes engines have more power, and the increased efficiency results in cooler water and exhaust temperatures at WOT and in yellows.



The best module is the GM D1906 or the MSD horseshoe shaped replacement with the rev limiter. Other modules can be spooky at low voltage, like cranking with a weak battery.

The Oldsmobile that had .090” plug gap was the late 70’s MISAR system, which was GM’s version of the Mopar Lean Burn. Because that ignition controlled the timing with an external computer the spark fired at a different time after the trigger impulse. The trigger point is fixed and the actual spark firing occurs at some other time determined by the computer. Because the HV coil in the cap and the trigger pick-up coil are so close to each other, the magnetic pulse of the coil firing can cause a re-trigger signal (it will, LOL if you mix the coils) and the timing will go crazy. For that reason, the coils for ECU controlled timing are wound with opposite polarity than standard HEI coils. You cannot use the ECU timing controlled coils with standard HEI (and visa-versa). The coils are identified by color code of the primary wires.

Besides the fact that they all have the same electrical values and the same energy output, the point is the Olds coil “for .090” gap” will not work with a regular HEI …. and has no higher energy anyway.

Wide plug gaps are nonsense. If a wide gap improves anything it is because the AFR isn’t right.

There are several different pickup coils also, ECU and regular advance and CW and CCW rotation for both ECU and regular advance. The magnets have opposite polarity, North up on some, North down on others. They are identified by wire color and color of the plastic connector. Very strange things happen to the timing if the pickup coils and magnets are mixed up.

The best thing you can do for an HEI is power it through 10 ga. wire and a switch capable of handling 30 amps + some room to spare.

[Krooser]

Darn-it… I thought I had my screen set for sans serif not sanskrit!

[Tuner]

[Grocerius Maximus]

Sanctioning bodies haven't addressed the advantage to the crate yet- 60+ lbs off the front. ONLY aluminum head allowed in most cases. Plus then IMCA gave them an effective spoiler, then decided to placate by taking most of it away and STILL not addressing the basic advantage. So they had cars that turned in and thru the center better always, and drove off much better in the slick.

Make the crates put 30 lbs each side between the motor plate and the radiator ABOVE the horizontal motor mount location what do you think will happen?

Fast teams will still be fast regardless of rules, but rules tend to make people spend money just to try it.

[les327]

I thought I was posting in English but it must be coming up on some browsers in ancient Sanskrit.

Having the correct mechanical curve is not about “reducing power so a (poor) driver can flatfoot the throttle on a slick track”, a good driver controls the power with his right foot.

The correct ignition curve maximizes efficiency and makes maximum power available at all engine RPM.

The correct vacuum advance only adds additional timing when the engine is at very light load, like on yellow flag laps.

Engines need more timing when they are at light load.

The correct timing at any load, WOT or in yellow, makes engines have more power, and the increased efficiency results in cooler water and exhaust temperatures at WOT and in yellows.



The best module is the GM D1906 or the MSD horseshoe shaped replacement with the rev limiter. Other modules can be spooky at low voltage, like cranking with a weak battery.

The Oldsmobile that had .090” plug gap was the late 70’s MISAR system, which was GM’s version of the Mopar Lean Burn. Because that ignition controlled the timing with an external computer the spark fired at a different time after the trigger impulse. The trigger point is fixed and the actual spark firing occurs at some other time determined by the computer. Because the HV coil in the cap and the trigger pick-up coil are so close to each other, the magnetic pulse of the coil firing can cause a re-trigger signal (it will, LOL if you mix the coils) and the timing will go crazy. For that reason, the coils for ECU controlled timing are wound with opposite polarity than standard HEI coils. You cannot use the ECU timing controlled coils with standard HEI (and visa-versa). The coils are identified by color code of the primary wires.

Besides the fact that they all have the same electrical values and the same energy output, the point is the Olds coil “for .090” gap” will not work with a regular HEI …. and has no higher energy anyway.

Wide plug gaps are nonsense. If a wide gap improves anything it is because the AFR isn’t right.

There are several different pickup coils also, ECU and regular advance and CW and CCW rotation for both ECU and regular advance. The magnets have opposite polarity, North up on some, North down on others. They are identified by wire color and color of the plastic connector. Very strange things happen to the timing if the pickup coils and magnets are mixed up.

The best thing you can do for an HEI is power it through 10 ga. wire and a switch capable of handling 30 amps + some room to spare.

I thought the revese wound coils were for cars with the startre on the drivers side
To compensate for the magnetic field from starter giving a false (advanced) trigger reaking havoc on starters?any thoughts on that ?

[Tuner]

I suppose when you start the car it depends on if it is parked facing North or South. I don't think East and West would matter. Sunspots, you got to beware of sunspots. If there's big Aurora Borealis it will probably backfire right out the top of the battery.

[les327]

I suppose when you start the car it depends on if it is parked facing North or South. I don't think East and West would matter. Sunspots, you got to beware of sunspots. If there's big Aurora Borealis it will probably backfire right out the top of the battery.

LOL. i wondered why the diffrent coils and pickups learn something new daily. I have seen the problems wjen they are mixed.

[Krooser]

At the risk of getting off track here I will have to admit I'm pretty old school about racing and cars (and other stuff)… 'Back in the day' we ran on dirt and some pavement with the same cars. Big blocks, small blocks, FE's, 427's, 350's 302, 3 speeds, four speeds… Pontiac's, Oldsmobiles and Hemi's...no restrictions on engine size, make or model. No weight limits.

On any given day a 350 could beat a 396 or an FE Ford could take home the cash. Now there are so darn many rules you have to be an attorney to know what's legal or not. Now I'm not advocating wide open, money is no object racing here. Quite the opposite. We ran what we had in stock for the most part. And most of us raced a heck of a lot cheaper than you can today… even with inflation taken into account. We never built a car with a credit card. Our catalogs were row after row of cars at the junk yard.

We built our own engines. Today you have to have a 'brand name' engine in your car. Now most drivers wouldn't know how to mic a crank or fit a piston if their life depended on it.

Today's racer is sooo indoctrinated with the idea that you should only run 'sanctioned' races… run for points. Same rules everywhere. Well you can't eat points (as my old racing buddy Louie used to say). We ran where the money was best or wherever the track was the closest. No entry fees… no association fees… we ran for 40% of the gate. We actually encouraged our friends and neighbors to come out and watch us compete since we ran for a percentage and the more asses in the seats the more $$$ we made. We advertised the race tracks on our haulers and trailers… "Follow me to ABC Speedway"… we had open trailers and folks could see that we were racers. They didn't have to wonder what was in some 53' stacker being pulled by a Peterbilt. We worked on our cars in our driveways or at Joe's Corner Gas Station not in a 3000 sq. ft. steel building in some faceless industrial park.

Our races are filled with 'me too' cars that bear little resemblance to street cars. Street stocks and four cylinders put on great shows whether or not we think of them as 'real' race cars. Today promoters prep their tracks not for maximum traction on a tacky track… nope they have to make sure it's smooth and slick (and dusty) at feature time so the 'bar cars' don't lose bite running thru even the smallest rut or hole.

Yeah the world has changed… today I see Saturday night shows with 400 heads in the bleachers and 30 cars in the pits at many tracks. I think back to when we could draw over 100 cars and pack in 2,000 fans at any rural podunk track and 4-7,000 in the metro areas. Some tracks DO have good car counts… but too many struggle to survive with dwindling car counts, increased costs and poor crowds.

Man I got off track here… what I started to say was if you can't beat a 400 HP crate motor with a 600 HP open motor you have more things to worry about than the 60 lbs' difference in weight. Our 4000# boat anchor Fords with 390's and 406's won more than their share of races against the best GM guys with 327's and exhaust pipe roll caged 2600# '56 Chevy's.

Soap box off...

[novadude]

Not that it has anything to do with this post, but I think Krossers rant applies to just about any form of racing today. Think of how much cooler Indy would be if you still had the weird mix of cars you saw 50 years ago. Drag racing and NASCAR was much less "cookie cutter" in those days too.

[Krooser]

Not that it has anything to do with this post, but I think Krossers rant applies to just about any form of racing today. Think of how much cooler Indy would be if you still had the weird mix of cars you saw 50 years ago. Drag racing and NASCAR was much less "cookie cutter" in those days too.

Thank you for your support...