distributor re-graph machine vane type red in colour
Moderator: Team
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jwojtasi
distributor re-graph machine vane type red in colour
Hi guys have just bought my self a vane dizzy strobe seconhand. and i have no information on it . can someone help me with advance curves total s etc asperrated / turbo and blowen. what other factors do i need to consider. rpm timming . how do i make it work with the cam shaft or are there other factors . or can someone recomend a book or a person or persons / site thanks ray wojtasik brisbane australia.
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bill jones
- Guru
- Posts: 2650
- Joined: Sun Sep 05, 2004 6:38 pm
- Location: salt lake city, ut
- Contact:
-have you used this machine yet? and tested more than one distributor to see what the curves are?
-You have to have SOME experience before the numbers mean anything.
-It doesn't really make sense to me to be worrying about the grand scheme of it all until you have something specific to talk about.
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-But in general, the curves of a distributor are primarily used on street engines about 15 to 20 years old as automotive EFI and computers now have control of the ignition timing, so you'd only be using the machine to do old stuff.
-Typically a racey style engine would only have a very short curve, something that basically just retards the timing enough so that the engine will start easy---then advances real quick to maybe 15 to 20 (crankshaft) degrees and this is usually as soon as you can get it like fully advanced at 2000 to 3000rpm.
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-So if you wanted a total timing number of something like 38 degrees for a normally aspirated small block and you had 20 degrees of advance in the distributor that is fully advanced at 2500rpm, you'd set the idle or cranking timing at 18 degrees.
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-I live in a 4200 to 6800 ft elevation enviroment and on oval track and bracket racing drag cars we usually set the initial at 22 to 26 degrees and the total might be anywhere from 36 to 44 degrees and we always want this total advance between about 2400 and 3000.
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-street cars are much more difficult because you need the timing to be within about 2 degrees of ping at every rpm and every throttle position and at every inch of manifold vacuum so you have to do a LOT of effort quite often to get the initial---the slope of the mechanical curve---and the integration of the vacuum advance amongst that mechanical slope.
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-Many people never use the vacuum advance on performance engines but for a street drven performance engine the vacuum advance adds immensely to the cold driveability and the part throttle driveability responsiness of the engine.
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-There's a lot about using a distributor machine that takes TIME to learn and to learn what it takes means you have to document what the curves are that your distributor has---go run it in a car---and see what happens---then change the distributor curve/s until you find what makes the engine really happy.
-You have to have SOME experience before the numbers mean anything.
-It doesn't really make sense to me to be worrying about the grand scheme of it all until you have something specific to talk about.
-----------------------------
-But in general, the curves of a distributor are primarily used on street engines about 15 to 20 years old as automotive EFI and computers now have control of the ignition timing, so you'd only be using the machine to do old stuff.
-Typically a racey style engine would only have a very short curve, something that basically just retards the timing enough so that the engine will start easy---then advances real quick to maybe 15 to 20 (crankshaft) degrees and this is usually as soon as you can get it like fully advanced at 2000 to 3000rpm.
-----------------------------
-So if you wanted a total timing number of something like 38 degrees for a normally aspirated small block and you had 20 degrees of advance in the distributor that is fully advanced at 2500rpm, you'd set the idle or cranking timing at 18 degrees.
-------------------------------
-I live in a 4200 to 6800 ft elevation enviroment and on oval track and bracket racing drag cars we usually set the initial at 22 to 26 degrees and the total might be anywhere from 36 to 44 degrees and we always want this total advance between about 2400 and 3000.
------------------------------------
-street cars are much more difficult because you need the timing to be within about 2 degrees of ping at every rpm and every throttle position and at every inch of manifold vacuum so you have to do a LOT of effort quite often to get the initial---the slope of the mechanical curve---and the integration of the vacuum advance amongst that mechanical slope.
-------------------------------------
-Many people never use the vacuum advance on performance engines but for a street drven performance engine the vacuum advance adds immensely to the cold driveability and the part throttle driveability responsiness of the engine.
-----------------------------------
-There's a lot about using a distributor machine that takes TIME to learn and to learn what it takes means you have to document what the curves are that your distributor has---go run it in a car---and see what happens---then change the distributor curve/s until you find what makes the engine really happy.
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jwojtasi
vane 405 dizzy strobe
thanks for that info . tried a stock curve in a 308ci 5lt engine . engine is 030 " over bore comp ratio of 9.5:1 head port flows 185cfm cam duration @ 050 240 and lobe seperation 110. timming 37/ 45 ran factory curve of 4-8@1000 19-23@4800 ran faily ok ? tried to have the timming all in by 3000-3500 rpm and pulled up the primary to start the advance @1500rpm turned into a dog ended up runing 20deg on nose to get the dame thing of the line. and lost top end . ended back at a simalair curve but with less total at max rpm. how do i set up the dizzy using the ping point . thanks again 
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bill jones
- Guru
- Posts: 2650
- Joined: Sun Sep 05, 2004 6:38 pm
- Location: salt lake city, ut
- Contact:
-The experiences you have shown here are what lead you to getting the curves really right for each engine, and somethimes you have to "work" with the curves to get all there is to get.
-Low compression and big cams (and high altitude) mean that you'll have low cranking compression numbers so when you have low cranking compression numbers like 150# or less then you'll always need more intitial or static timing and the curve from cranking speed to say about 1200rpm you can have maybe as much as 10 degrees happen real quick.
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-The main reason for an advance curve maybe should be stated a different way.
-If you called it a "retard curve" for starting and for low rpm wide open throttle maybe it would make better sense.
-All you are trying to do is retard the timing so the engine will start easy and then keep the timing just barely under the "ping point" the rest of the time.
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-When you really have the problems is when you have cranking compression over 200# because this engine will ping so easy---even at part throttle.
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-Two words of caution---make sure you test the timing curve of every distributor to at least 1000rpm over the maximum rpm you intend to ever run that distributor---so that you know for sure that unwanted advance (or retard) doesn't happen at the high rpms.
-GM HEIs are really bad for having advance happen at high rpm.
-AND----any magnetic triggered distributor that you have the advance curve fully advanced at a low rpm say around 3000 or less----they tend to retard as the rpm goes up----maybe 3 to 8 degrees at 8000rpm.
-Low compression and big cams (and high altitude) mean that you'll have low cranking compression numbers so when you have low cranking compression numbers like 150# or less then you'll always need more intitial or static timing and the curve from cranking speed to say about 1200rpm you can have maybe as much as 10 degrees happen real quick.
----------------------------------------------
-The main reason for an advance curve maybe should be stated a different way.
-If you called it a "retard curve" for starting and for low rpm wide open throttle maybe it would make better sense.
-All you are trying to do is retard the timing so the engine will start easy and then keep the timing just barely under the "ping point" the rest of the time.
----------------------------------------------
-When you really have the problems is when you have cranking compression over 200# because this engine will ping so easy---even at part throttle.
------------------------------------------------
-Two words of caution---make sure you test the timing curve of every distributor to at least 1000rpm over the maximum rpm you intend to ever run that distributor---so that you know for sure that unwanted advance (or retard) doesn't happen at the high rpms.
-GM HEIs are really bad for having advance happen at high rpm.
-AND----any magnetic triggered distributor that you have the advance curve fully advanced at a low rpm say around 3000 or less----they tend to retard as the rpm goes up----maybe 3 to 8 degrees at 8000rpm.
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jwojtasi
VANE 405 BILL JONES
THANKS BILL ANOTHER THING THAT I NOTICED WAS THAT SOME OF THE DIZZYS THAT HAVE MODUELS ON THEM RETARD THE TIMMING COMING OF THE LINE EG. STROBE SET ON O SPEED IT UP AND JUST AS YOU THOUGHT THAT IT WOULD ADVANCE THE SPARK LINE RETARDED 5DEG AND THEN STATRED TO ADVANCE? THEN AT THE END OF THE MAX RPM IT RETARED AGAIN. CAN THESE MODULES BE TRICKED EG. RESISTOR IN LINE? IS IT POSSIBLE TO CHANGE THE DWELL, SOME HOW , YER IT DROVE ME NUTS. THIS ENGINE HAD A FUEL SURGE @ 5500ENG RPM IT HAD BEEN TO A FEW SHOPS AND THEY SAID THAT THE PERSON THAT RECO THE Q-JET MADE IT TO LEAN?? SO I DONT KNOW WHY I WONDERED OF INTO THE WOODS WITH THIS ONE AS I DID THE Q-JET. HAD IT APART SO MANY TIMES AND NOTHING WRONG . THEN THE STROBE CAME INTO MY LIFE. AS ABOVE THE DAM MODULE WAS RETARDING AS MUCH AS 8-10DEG @ THIS RPM PROBLEM SOLVED. OWNER STILL THINKS THAT I REPAIRED Q-JET. USED A 4 CYL MITSUBISHI MAGNA MODULE. THIS CASE COST ME A BUNDEL IN HAVING TO TRY DIFFERENT MODUELS / CARBY KITS / SO MUCH BOOLY TIME. HELP WITH MY LEARNING CURVE IS GREATLY APPECATED.
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bill jones
- Guru
- Posts: 2650
- Joined: Sun Sep 05, 2004 6:38 pm
- Location: salt lake city, ut
- Contact:
-where you are on the opposite end of the world from me you have entirely different choices of parts to work with, and I probably haven't ever experienced any of the same sort of distributors and modules.
-I can tell you that I have burned up a bunch of electronic modules and gadgetry over the years.
-I have my machine made up so that I can test entire ignition systems and I have gauges to monitor the voltage, amperes, dwell, ohms, etc.
-I use a timing light rather than the internal strobe because my machine is an old Sun machine that had 6 volt internals.
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-As far as using a resistor or some other method to trick the module I haven't found anything worth talking about but testing and finding better modules and then adapting to a better module is one of the better ideas.
-you also need to have spare distributor caps with "windows" cut into them so you can view the "rotor index" and the gap across the rotor to the inner cap terminals.
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-I have a method that I can change the multiple spark gaps from from 1/8"(3.2MM) out to about .700" (17 to 18mm) so that I can find the places
the spark jumps off to, and you need to test in the dark sometimes so that you can see the electrical activity leaking off at the coil terminals and from the plastic of the E-core coils to the large coil frame, then figure out what to do about all that energy going to waste.
-Stock ignitions will only jump about .400" (10MM) where a MSD will do twice that when everything is clean and there's no no place for the spark to take to ground.
-I can tell you that I have burned up a bunch of electronic modules and gadgetry over the years.
-I have my machine made up so that I can test entire ignition systems and I have gauges to monitor the voltage, amperes, dwell, ohms, etc.
-I use a timing light rather than the internal strobe because my machine is an old Sun machine that had 6 volt internals.
---------------------------------------
-As far as using a resistor or some other method to trick the module I haven't found anything worth talking about but testing and finding better modules and then adapting to a better module is one of the better ideas.
-you also need to have spare distributor caps with "windows" cut into them so you can view the "rotor index" and the gap across the rotor to the inner cap terminals.
--------------------------------------
-I have a method that I can change the multiple spark gaps from from 1/8"(3.2MM) out to about .700" (17 to 18mm) so that I can find the places
the spark jumps off to, and you need to test in the dark sometimes so that you can see the electrical activity leaking off at the coil terminals and from the plastic of the E-core coils to the large coil frame, then figure out what to do about all that energy going to waste.
-Stock ignitions will only jump about .400" (10MM) where a MSD will do twice that when everything is clean and there's no no place for the spark to take to ground.