On GM HEI distributors these weights and springs are just under the rotor cap.
Jun 7, 2023
A final word about that "module:" Lotsa
Truth: This myth is only true when the comparison is to a stock HEI distributor, says Davis. This firing ability also allows the use of wider spark plug gaps. We re-assembled the distributor and put it back in the car. ( 20 ), HEI Distributor Upgrade Kit, 50,000 V Coil, Red Cap, Red Rotor, GM, Kit, 5.0 out of 5 stars
When discussing reliable, easy-to-use ignition systems, the HEI distributor is one that securely tops the list. To get some solid information you can store in your noggin, we reached out to Steve Davis of Performance Distributors.
We recommend these similar substitute parts: 4.5 out of 5 stars
Stay Updated with Emails from Summit Racing. Centrifugal advance keeps the combustion process in time with the piston location. Estimated Ship Date: Today.Loading Estimated Ship Date: Today. In fact, at wide-open throttle, there is no vacuum advance. This HEI module is available for all HEI distributors and it mounts in the same location as the stock unit by replacing the entire module and wiring harness assembly. Make sure you get the right one for your balancer- 6", 7",
to max. dba Summit Racing Equipment | Trademarks, Everything You Need for Anything You Drive, In Stock at a Summit Racing Location. rpm and is full in at 3000 rpm. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. The lower amperage draw actually results in a much cooler running HEI coil. The purpose of the vacuum advance is to provide spark advance when the engine is not spinning fast enough to create the centrifugal advance talked about earlier. Your highway mileage will be off by about 5 MPG and your plugs
Jul 5, 2023
If that's not
The second step is to tune how fast that the distributor reaches total advance. get the centrifugal side really dialed in for maximum performance. At this point, you can use a timing light to confirm that the initial timing is where you set it, and then check the timing from idle to 3,500 rpm in 500 rpm increments. degrees if plugged into our previous example- OUCH!). advance with EGR = 51 total. plate of the vacuum can. better. Randy Bolig has been working on cars and has been involved in the hobby ever since he bought his first car when he was only 14 years old. Proform GM HEI Distributor Tuneup Kits 141-796. Black Ghost Hemi Challenger Street Racer Find a New Home. Unfortunately, enthusiasts are never satisfied with OE applications. ( 2 ), 4.29 out of 5 stars
( 9 ), HEI Distributor Upgrade Kit, 50,000 V Coil, Cap, Rotor, GM V8, Blue, Kit, 5.0 out of 5 stars
Its simple, easy to
Another way to eliminate those stray HEI sparks from finding a ground path is to use the plastic rotor screws from Performance Distributors.
HEI distributor? | Team Camaro Tech You can adjust these cans with a small 3/32-inch Allen wrench inserted into the vacuum nipple. I
the instructions are pretty vague on how to install it. Advance does, I will try to describe it. . Its simple, easy to tune, and plenty powerful to light off any naturally aspirated engine up to 7000 RPM if properly equipped.
notches.
advance. It has a higher output coil and module an adjustable rev. If I rev the engine quickly, sometimes it will come back to the original setting, but most of the time it does not.
trench into their pivot pins OR BOTH. I use a light silver and blue spring that comes with the distributor. Vacuum advance for the street: You want
with. Either one is a worthwhile upgrade for a hot street motor-
advance comes in at the right RATE relative to engine RPM. Also, a higher octane fuel is required for the engine, to help control detonation. know the instructions say mount it with notches facing the outside, this would be the same
advance, you are increasing the amount the rod can pull. Ships Today. This way, the distributor.
There are two types of vacuum sources that you need to be aware of; manifold and timed/ported vacuum.
Knowing exactly how much spark advance, in crankshaft degrees, is ideal for maximum performance can vary with static and dynamic compression ratios, combustion chamber shape, fuel octane, piston dwell time as related to crankshaft stroke length, and other factors. The chart below contains the mechanical advance values (in crankshaft degrees) for several GM center cam and weight combinations commonly found in some of the corporation's most popular '70s and '80s Chevrolet V8-powered passenger cars and light truck applications. properly equipped. I understand that I can unsubscribe at any time.
The lost art of servicing GM HEI | Hemmings distributor.
Maybe I'm wrong, I have been
Full Forum Listing. This will allow it to operate at its maximum potential. The stock weights and advance plate are perfectly acceptable for all but the
This greater resistance is often the cause of cross-sparking inside the distributor cap. I have the total vacuum set at 16 degrees
Please note that Checkout Prices will be in US Dollars. The art of distributor recurving is being lost to time.
HEI Distributor in a '67 Chevelle? | Team Chevelle ( 8 ), HEI Distributor Upgrade Kit, Cap, Rotor, 65,000 V Coil, Cover, Alkyd, Red, Universal, V8, Kit, 4.0 out of 5 stars
Like many parts and products offered to consumers, there always seems to be untruths and misinformation that get spread like wildfire. Mr Gasket sells an inexpensive distributor shim kit that you can use to reduce the overall endplay down to around 0.015 inch. You want it "all
If advance is measured at small increments of engine rpm, the timing figures created by the weights and springs as they move outward during engine acceleration will define the advance curve when plotted on a graph.
the top plate is tig welded to the main shaft to prevent breakage, Custom pick up coil . Jun 12, 2023
Truth: In reality, the advance curve typically found in a stock HEI distributor is not fully advanced until 4,000 to 4,500 rpm, which is very slow.
really know how much each turn limits though. advance. Some engines will idle too fast with the line connected to a manifold vacuum.
Tuning Up and Dialing In With an Upgraded Electronic Distributor springs instead. Often the spark burns through the rotor into the mechanical advance mechanism on its way to ground. Let's start with the coil. The 7.5 Amp MSD Digital Performance Module is unified with the coil for the most precise timing and dwell control. Stretch, The Tradition Continues: Valley Of Fire Cruise 2023, Event Preview: The Goodguys 17th BASF Nashville Nationals, This 1,100 Horsepower 66 Silverado Is The Wild One Of The Bunch. In general, cars with automatic transmissions with stock-type or even a slightly looser-than-stock torque converter respond well to more mechanical advance in the lower rpm range. tolerances.
Therefore, the spark from the distributor needs to be advanced as engine rpm increases. Reducing the endplay eliminates this problem. Estimated International Ship Date:
cans
With the stock vacuum advance is when you start getting
In effect, the HEI housing actually becomes a heat sink for the module. But I think the wrong springs are in it and want to check total advance. It should come as no surprise being one of the most popular options among modern rodders and race enthusiasts to this day. This gives me the advance rate above of starting at about 1100 and is full in at 3000
advance curve should be made on a distributor that suffers from these problems- fix it
After decades of pirating advance components from swap-meet and salvage-yard HEIs, our collection includes several dozen individual GM center cams and centrifugal weights. I have a MSD Pro Billet HEI
you'll get better response and HP especially at higher RPM where the stock one hits a kind
MSD HEI Distributor Upgrade Kit - NAPA Auto Parts The best rebuild procedure is to completely disassemble the distributor by unbolting the vacuum advance, module, removing the drift pin and gear and yanking the shaft. It was used exclusively by all GM brands beginning in 1975 and it carried on throughout the '80s. ( 12 ), HEI Distributor Upgrade Kit, Coil, Cap, Rotor, 48,000 V, Black, Chevy, GM, Kit, HEI Distributor Upgrade Kit, Coil, Cap, Rotor, Module, GM, Kit, 3.43 out of 5 stars
Is there anything I can do with the est wire (white) and the bypass wire (tan) to address this problem? It includes a external Blaster 2 coil and a special dust cap
It didnt take GM long to rectify the situation by modifying the modules and coils to offer increased spark energy at higher engine speeds.
What the Crane unit does is adjust the amount of vacuum
You can order this part by Contacting Us. Most distributors include a vacuum advance mechanism, which consists of a diaphragm vacuum canister, an arm from the canister to the breaker plate, and a hose connected to an engine vacuum source. You won't need a dial back timing light to use it
for really hot 60s muscle car motors had as little as 8 degrees total advance in them,
A new coil is also a lot cheaper than a complete MSD ignition
On a typical stock engine, you usually see around see 8-13 degrees. coil and module. Tri-Fives and Classic Trucks Hit the Coast: Huge Cruise Gallery!
If you are located in the United States select "Apply" to have access to US delivery options and In-Store Pickup. Truth: It is not. Reliability, a simplistic design with many interchangeable components, and heavy support by OE-replacement and aftermarket manufacturers alike makes GM's HEI among the best executed distributor systems ever produced.
one. energy (like 50% more).
If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. do you are looking to install one Blue (heavy) spring and one Silver one (medium). top right hand corner. and 16 degrees of vacuum advance. That's why I say its important
Installing lighter-tension advance springs in an HEI that remains in its original application is oftentimes enough to produce noticeable results. This can help to keep your plugs cleaner. "engine" that makes the sparks. ( 35 ), Estimated USA Ship Date:
This way, the distributor body can be thoroughly cleaned, lubed, and reassembled. unplugged? But get a good GM
Your email address will not be published. On Carter/Edelbrock carburetors, the timed port is on the passenger side and the manifold is on the drivers side. One way to do this is by using a high-quality relay to offer switched power to the distributor. These modern takes on a vintage ignition have fueled the market and fired the combustion of an untold number of engines. THE ADVANCE SETUP: Centrifugal and vacuum
The preferred vacuum source is the timed source. your #1 plug wire then you have the distributor installed off by a few teeth. International Customer Options|In the United States?
Jul 31, 2006. If you spend any time at a speed shop or race track, you have inevitably heard someone mention where their timing is set. it cool off before it would run.
distributor will be turned clockwise (around toward the passenger side) a fair amount from
Required fields are marked *. decided to try this.
The 30 degree mark will be located clockwise (viewing the balancer from the front of the engine) from the existing 0 mark, which is also 1/12th the circumference of the balancer . Jun 23, 2023
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There is also a stop tab for the arm. Because you mentioned you have an aftermarket HEI, well assume that it may be only a few years old. The seven- and eight-pin modules are used on early computer-controlled engines that use fixed-timing distributors. After the lockout is in place it should be in the same
Turning the Allen screw counterclockwise reduces the amount of advance the can will deliver. If the distributor is stock you might also consider adding a performance weight and spring package.
be toward the back of the distributor and the notches will be towards the inside. These springs are located directly under the rotor and are easy to remove/replace by hand
to go with it.
total amount of vacuum advance. This epoxy dissipates heat more efficiently than oil-filled coils.
Manifold vacuum is a direct connection to the intake manifold, and if the hose is connected to this port, you will have full vacuum in the line at idle.
Today. Jun 19, 2023
has a better advance curve and more total timing than any emissions distributor, like your stock Motorcraft, (well engineered, good distributor), but lacks a real spark curve for more efficient combustion. about 3200 rpm. ( 8 ), Estimated USA Ship Date:
for sharp performance and long coil life. you add the advance lockout and limit the amount of vacuum advance you are rotating the
messy.
If you don't have the
Inspect the mechanical weights to see if they move freely on their pivots.
Compounding that is the fact the internet affords anyone with an opinion a worldwide venue to spout what they think is true.
We removed the distributor gear roll pin and removed the gear and separated the shaft from the distributor. Jun 13, 2023, HEI Distributor Upgrade Kit, Cap, Rotor, 65,000 V Coil, Cover, Alkyd, Red, Universal, V8, Kit, 4.0 out of 5 stars
Dyno testing has shown that most small blocks running Premium pump gas with 9.0:1 9.5:1 compression make peak horsepower with roughly 38-42 degrees of total advance. For a street car, forget it. of "wall".
Explore Our Forums. highest HP/RPM engines. rpm. Other good ideas to help tune up your HEI includean adjustable vacuum advance canister. Grab a sharp 1/8" drill bit and a slightly larger 5/64" drill bit. Someone was asking about what springs I use for the mechanical
It has 16 degrees built in which is what's needed when running a EGR. For blown or nitroused applications I always recommend
The farther out (counterclockwise) you
plate (that pivots around the main distributor shaft as the centrifugal advance moves it)
Often the spark burns through the rotor into the mechanical advance mechanism on its way to ground. distributors for more than 40 years. These myths and untruths have been perpetuated for decades, and its hard to believe that many still believe them.
There remains a strong following for those seeking a low-buck approach and if that describes you, hopefully recurving an HEI has just become easier for you!
At idle, with the vacuum advance hose disconnected and plugged at he carburetor, this is the timing that you see with the timing light on the timing marks. advance is not worn out because when the weights wear themselves "oval" and the
I could go with 2 to 4 degrees higher on the initial
Sep 13, 2018 Reliability, a simplistic design with many interchangeable components, and heavy support by OE-replacement and aftermarket manufacturers alike makes GM's HEI among the best executed. Conversely, high octane fuel can handle slightly more timing advance. Can you just leave it
Damon has already said. There are several available through various companies like Accel, Moroso, Spectre, and Summit Racing to name a few. Use your Summit Racing SpeedCard today, and get 10% back - Get Details! ALL stock HEIs that were installed in V8s are designed to
As Damon said, about 2 notches less than maximum is
(30). You can order this part by Contacting Us. Jun 22, 2023
For performance driving, the best acceleration comes when total advance is achieved before 3,000 rpm. Engines with 9.5:1 10.5:1 typically require 35-38 degrees total. with no modifications with high performance sticker on top, Magsarus hei dist 500-0 features include: rotor indexed and evenly spaced to the cap, our (drive spindle) is modified for in housing oil control. Don't panic, this is normal. The real beauty of the GM HEI distributor is its longer ignition coil dwell time that can deliver greater ignition current to the spark plugs at high rpm.
( 8 ), Estimated Ship Date:
At least this HEI distributor is not the fugly humongous one that most of the vendors sell.
You note that the centrifugal advance curve that I recommended above
3. You will get
We cleaned the old grease, added new white lithium grease, and reassembled the distributor to find it now works just like new.
The solid epoxy eliminates the possibility of leaks. We'll send you the most interesting Chevy Hardcore articles, news, car features, and videos every week. The HEI distributor consists of a control module and a magnetic pickup inside the housing that replaces the previously used contact points and condenser. ( 35 ), HEI Distributor Upgrade Kit, 50,000 V Coil, Cap, Rotor, GM V8, Black, Kit, 4.48 out of 5 stars
What have you installed and also, where did you find them? if ordered today, HEI Distributor Upgrade Kit, Power Coil, Cap, Rotor, GM, Kit, 4.71 out of 5 stars
Hei Ignition Systems - Modified Stock - Circle Track Magazine - MotorTrend The
(From right to left) The four-pin module was used on carbureted engines with a traditional vacuum and centrifugal advance. timing set at 13 BTDC, partly because of the distributor not being up to par. I might end up buying a new one instead of rebuilding the old one. This is the latest update to my ignition adventure. I hope this clears it up for you.
Locking out timing on HEI (here's how to) | NastyZ28.com You can change the rate of advance by changing the centrifugal advance springs to lighter ones. With the MSD HEI Distributor Upgrade Kit, you can improve the performance of your early model GM HEI distributor.
After yearslong delay, DEA revokes license of drug distributor over dba Summit Racing Equipment | Trademarks, Everything You Need for Anything You Drive, In Stock, Including at a Supplier. This large cap distributor first appeared on small block Chevy engines in the middle of 1974 and remained well through the '90s in various other forms.
The HEI Distributor: Clearing The Confusion And Debunking Myths Estimated International Ship Date:
This need for advance is why distributors have an advance system built-in. After reading the above article, I
Today, HEI Distributor Upgrade Kit, 50,000 V Coil, Cap, Rotor, GM V8, Red, Kit, 4.21 out of 5 stars
Use your Summit Racing SpeedCard today, and get 10% back - Get Details! with a dial-back timing light, I noticed that instead of 20 degrees of centrifugal advance
Factory advance curves are engineered to provide acceptable performance and emissions control.
A single 12-volt wire is all that is required to function, and it can be easily stabbed into any distributor-fired Chevrolet engine. Truth: As long as your Number One cylinder is at top-dead-center on the compression stroke, it does not matter which terminal you use for your Number One plug wire.
The advantage of the HEI distributor is its longer ignition coil dwell time that can deliver greater ignition current to the spark plugs at high rpm.
As engine load or throttle position increases, the vacuum decreases, and so does vacuum advance timing. Today, HEI Distributor Upgrade Kit, 50,000 V Coil, Cap, Rotor, GM V8, Black, Kit, 4.48 out of 5 stars
That one even has the coil built into the cap which this one does not have.
it (2 per side). TIMING!!! with how much "dwell". Adjustable vacuum advance canisters are easy to spot because the can is shaped like a hexagon with six distinctive sides. If you look
None of the aftermarket HEI advance curve kits included center cams and/or weights shaped identically to GM's high-quality originals. aka HurdRep, Denver Dave and keeper of various 55 and 57 Chevys, , 67SS396 Convertible, , 40 Ford, 51 Mercury and a real 32 Ford three window coupe, for balance. Tri-Fives and Classic Trucks Hit the Coast: Huge Cruise Gallery!
But what happens when installing a used HEI in a non-stock application? You can also lose a small amount of spark intensity when you run a coil wire to an external oil-filled coil. The weights pivot on pins that are attached to the distributor shaft, and the center plate is attached to the movable assembly that holds the rotor. Ignition is the point at which combustion actually occurs in an engine. once the timing mark on the balancer starts "crawling up behind the water pump",
I know its an oddball question.
( 7 ), HEI Distributor Upgrade Kit, Coil, Cap, Rotor, Module, Chevy, Cadillac, Blue, Kit, 4.45 out of 5 stars
The brown iron deposits are the result of this oxidation. I'm looking at THIS MSD HEI Up Grade Kit.
Both blue springs start advance at about 800 rpm and is full in at
This is a vacuum
that reduces dwell at lower RPM to keep the coil from over saturating.
Often this is all that needs to be done.
Unlike some performance distributors that are 0.E.M. Instead, the kits share a common, oddly-shaped set that was little more than a one-size-fits-all assembly. Finally, if running an engine with a compression ratio above 10.5:1, total advance should not go higher than 35 deg.
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What that means is, if you are shooting for 40 degrees of total timing, and your distributor allows 30 degrees of mechanical advance, that would require the initial timing to be set at 10 degrees.
If you find a distributor like this, its best to just keep looking for one in better condition.
as what I have stated, but with no advance locked out.
Estimated International Ship Date:
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at about 800 RPM and ends at 2800. This is done so that the combustion process occurs at the optimal time to efficiently push the piston down the cylinder.
( 7 ), HEI Distributor Upgrade Kit, Flame Thrower, Black Cap, Rotor, Module, Harness, Kit, 3.63 out of 5 stars
April 16, 2015 Performance Distributors has been working on GM HEI units and making its own Davis Unified Ignition (D.U.I.) Although we gave some guidelines, each engine is different and might like a different timing setting. How and Why to Adjust a Holley Carburetor Accelerator Pump, Do Not Sell or Share My Personal Information. The advancing of engine timing, via the vacuum advance, immediately begins to decrease as soon as you accelerate. Estimated International Ship Date:
you need to hook it up.
like it is supposed to be, I had about 23 degrees. As high-end speed shops with distributor testing equipment fade away, so are the number of home hobbyists who truly understand the reliable-but-time-consuming method of swapping parts and testing with an adjustable timing light.