RO78IN Posted July 7, 2015 Report Share Posted July 7, 2015 Ok, so searched for the last 30 minutes with little success. I'm building my 3k now, and the new 5k dizzy i just bought from Golbys has 2 vacuum ports. What the hell am I meant to do with these? Hook one up (and if so - which one) or both? I've heard that the curve on these is pretty shit > which is ok, its for a race motor, so hopefully it will be spending its life north of 4000rpm anyway, but is it worth locking it? Thanks in advance for your help matt Quote Link to comment Share on other sites More sharing options...
parrot Posted July 7, 2015 Report Share Posted July 7, 2015 If it's for a race motor, get it recurved for mechanical advance only to suit the characteristics of your motor. A race motor doesn't use vacuum advance. Quote Link to comment Share on other sites More sharing options...
Banjo Posted July 7, 2015 Report Share Posted July 7, 2015 (edited) Hi Matt, Like Parrot advised, you really don't need the vacuum advance/retard when you are racing. However, to answer your query, the port on the end of the vacuum actuator part of the dizzy (horizontal) is the port that connects to your carby vacuum. I think the one on top (vertical), is only to port the actuator to atmosphere. Someone can correct me if I'm wrong. You're right that the 5K dizzy was a bit sluggish, as it was used by Toyota on commercial vehicles & forklifts. The best way to use the 5K dizzy is to lock it up, and then feed the fixed trigger signal, without vacuum advance\retard into a programable electronic ignition controller, where you can adjust the advance curve to your hearts content. The electronic advance will always be more responsive that the spring loaded advance weights in the bottom of the dizzy. Locking up the dizzy is not hard. I actually did one at the weekend. Just remove the springs & advance floating weights & then lock the top & bottom plates together with a couple of little metal bars with a hole in each end. I sealed/connected the plates to the pins with a big blob of Araldite. There was no movement at all. Make sure you have the dizzy shaft & base together, (as if the springs were pulling them together / no advance) I found it easier to remove the complete shaft from the dizzy. Just drill out the pin through the helical cog & shaft at the bottom. Refit afterwards using a 5mm roll pin. The 5K dizzy came in two (2) forms. One with "reluctor" trigger sensor only, which fed an external ignitor to drive the coil. The other has an inbuilt ignitor connected directly to the coil -ve terminal). This model with inbuilt ignitor is simple to connect to an electronic ignition controller. Just connect the black wire that goes to the coil, to a 100 ohm 5 watt resistor (from Jaycar) and tie the other end to your 12V ignition supply to the coil. This will then give you a nice fixed switched 12V signal to drive/trigger which ever ignition controller you fancy. Cheers Banjo Edited July 9, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
RO78IN Posted July 7, 2015 Author Report Share Posted July 7, 2015 Thanks Guys, I'll pull it down tonight to see what we can do about locking it up. What is your preference for Coil and mappable ignition controller? Quote Link to comment Share on other sites More sharing options...
Banjo Posted July 7, 2015 Report Share Posted July 7, 2015 Hi Matt, Tell us what you plan for your 3K race engine, in terms of . . . . specs ? cam ? carby or injection ? compression ? head work / valves ? exhaust ? etc. and we will throw you a few ideas. Where are you located ? Who are Goldbys ? Cheers Banjo Quote Link to comment Share on other sites More sharing options...
GJM85 Posted July 7, 2015 Report Share Posted July 7, 2015 I had mine re-curved. Much faster super rev machine. Quote Link to comment Share on other sites More sharing options...
coln72 Posted July 7, 2015 Report Share Posted July 7, 2015 Played around with one of these years ago. Like you we had no idea how to hook up the vac advance so we grabbed the timing light and played. Turned out hooking both diaphrams up to the carby through a T piece gave the most advance, so we went that way. Quote Link to comment Share on other sites More sharing options...
RO78IN Posted July 7, 2015 Author Report Share Posted July 7, 2015 So the engine specs are: HEAD WORK: - changed combustion chamber profile to be even instead of that silly peanut shape - massively oversized valves - ported head - pretty big - Comp ratio is 12.5:1 static - around 8.7:1 dynamic Cam - Tighes 413 (259 @ 50" - massive) Motor - fully balanced bottom end GSXR1100 motor cycle pistons and H Beam aftermarket 4AGE rods Carbs - Twin webber 40mm (also have DHLA45's if needed) Still road registered (LOL) but more for hillclimbs and whatever Quote Link to comment Share on other sites More sharing options...
Banjo Posted July 9, 2015 Report Share Posted July 9, 2015 (edited) Hi Matt, You've spent some serious $$$ on your little old 3K. Are you planning to drive it to the track or hill climbs, or will it be "trailered" to events ? It's probably not going to be too happy about running around town in race trim setup ! If you've spent all those $$$ on the engine, & carbies. you should probably provide it with a good programable ignition system, to get the most out of it. You have lots of options for a N.A. engine without turbo. You should do a bit of research on the net. You can easily pay up to $ 2K+ for very up-to-date ignition controllers with software, but you could probably find an older Haltech, or similar device second hand on the net, that will do the trick. If you are so inclined, you could save a lot of dough, and have a lot of fun putting together a kit controller from Megasquirt or the local Jaycar electronic ignition kit. These will handle your 3K very well. Alternatively, as basically, you only need advance control, you could just get your 5K dizzy recurved for starters, as Parrot originally suggested. Let us know which way you go. Cheers Banjo Edited July 9, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
RO78IN Posted July 9, 2015 Author Report Share Posted July 9, 2015 So using a 6AL-2 system would be the go then? http://www.msdperformance.com/Products/Ignitions/6530_-_MSD_Digital_Programmable_6AL-2.aspx Then remove the mechanical and vaccum advances? Then wire in the 6AL2 as per this manual: file:///C:/Users/RemoteService/Downloads/6530.pdf using wiring of page 6 figure 3 (at the top)? Does this make sense and is the right way to play? Quote Link to comment Share on other sites More sharing options...
Banjo Posted July 9, 2015 Report Share Posted July 9, 2015 Hi Matt, What's your budget for an ignition control system ? The MSD CDI unit will set you back $ 500 +. The specs you need for your worked 3K are fairly basic, so you may find a more basic ignition controller like an older Haltech unit will suffice. Try ebay & Gumtree. You might be surprised what is out there. Just make sure they come with a loom. Everyone on this forum will have their own preference as to brand. P.S. My personal choice would be to not go CDI, as you need very high quality HV leads & seperation. You can get cross fire with them if the setup is not perfect, as a result of the very high voltages CDIs generate. Mainly happens on V8s where the spark plug leads lie side by side. The great advantage of using late model ignition controllers is the awesome graphics of the setup & real-time software that comes with them with their virtual dashboards. Cheers Banjo Quote Link to comment Share on other sites More sharing options...
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