Distributor Re-Curve

[bonkas]

Distributor Re-Curve - Does anyone in NZ still do this?

Going big cam (unsure of final specs yet), high compression and may need to change the timing on the standard distributor.

I have read about adjustable vacuum advance units but cant find anything in NZ apart from $800 distributor setups which still require modifications to work.. this is way out of my price range.

If anyone has done this and can offer any advice that will be appreciated.

This is in a 4g63 SOHC.

[tortron]

See tech section for a diy approach

[M.H.]

I ran one of these, easy enough to setup

 

https://wiki.autosportlabs.com/MegaJolt_Lite_Jr.

[bonkas]

Thank you very much @tortron I knew there was someth9ing on here but I couldnt find it via search. I narrowed the search down to that forum and found it. Giving it a good read now.

[kicker]

Does Quality Rebuilds Ltd in Manurewa do re-curving? Might be worth a call.

[RUNAMUCK]

I'm sure Barry Ems used to do it when quality rebuilds was in chch. 

[Mr.Mk1]

Gary at PAD Motorsport, chch 

[bigfoot]

What about some kind of msd type box device?

[bonkas]

On 9/25/2017 at 20:01, bigfoot said:

What about some kind of msd type box device?

Yeah have been mulling this over and over in my head but really defeats the purpose of the simple stock looking build I was after.

I tend to get lost in this sorta stuff very fast and I know I will give up so taking the easy and cheaper route.

I have been told Pickerall's (I Assume Pickerall Auto Electrical) in Hamilton does this, they are local so will look them up once my Cam is done.

[bonkas]

Pickerills no longer do this.

Am going to give Tuning and Performance in Hamilton a call.

The problem with the old school manual method is it requires a running engine but the timing changes need to happen before the engine can run.

[JoKer]

I built one of these once back about 2006 0r 2007

https://www.jaycar.co.nz/high-energy-ignition-kit/p/KC5513 $67.90

is it relevant to the thread? remaps via a simple little ECU, still got he MSD box & everything and a Hand controller for it

never used it, went Electronic ignition that came with the (new at the time) motor on the racecar anyway

theory was to lock the weights & use this to 'recurve' the ignition via the device

probably could "audrino" it these days for less effort / better results?

Edit : I see there's a 'special' on this version : https://www.jaycar.co.nz/programmable-high-energy-ignition-system/p/KC5442

Discontinued  WAS $94.90 Save $64.41 NOW : $30.49

Quote

Refer Silicon Chip
This is Silicon Chip's most advanced and versatile ignition system yet and can be used on both two & four stroke engines. The system can be used simply to intercept and modify the factory ignition timing or turned into a stand alone ignition system with remapped timing, electronic coil control and anti-knock sensing. The unit will trigger from a range of sources including points, Hall effect sensors, optical sensors, or the 5 volt signal from the car's ECU. Timing can be mapped against engine load and RPM and adjusted in step as small as 0.5°. Requires KC5386 and WC7502 with all pins connected.

Features:
> Timing retard & advance over a wide range
> Suitable for single coil systems
> Dwell adjustment
> Single or dual mapping ranges
> Two de-bounce settings
> Max & min RPM adjustment
> Suits 1 to 12 cylinder four stroke engines and 1 to 6 cylinder two stroke engines
> Optional knock sensing & correction

not sure again if applicable or useful info 

/ling

[Spencer]

Its going to depend on the dizzy to do this. Generally you need to really be able to have a range of springs (how quick the timing comes in) and the ability to adjust the max timing (the stop). Then once you have done these mods or got a dizzy that can be modified you then need to tune it on the road. You can setup a knock sensor and some headphones with some kind of amplifier (laptop) and go nuts tuning spark till your ears bleed.

I did some of this on my car but I am lucky enough to have a murican V8 so a new adjustable dizzy is a off the shelf item. I tuned it pretty bleeding edge (its a donk so timing all in @ 2500rpm) and then when it was extra loaded (like 6-700kg) on a very hot day up a hill I got some knock as my cruise RPM was way up. So lesson learned on safety margin and tuning for conditions. Lucky you can just pull over and guess dial it back to keep going.

I probably wouldn't trust a shop to do anything apart from some machine work if possible to make the dizzy adjustable? after that I can't imagine a shop road tuning a carby car for you without many hours being spent and lots of $$. Seems a journey best traveled in DIY and learning shit.

Saying all that the car will work with the stock dizzy for now (which you seem to think it wont from above comments?) all you may want to do is limit max timing (mod the stops) so you can put more base timing in.

Or electronic control like above but that ads complexity.

[kpr]

try it with the standard setup  first.  timing requirements probably wont change a whole lot. unless its a real aggressive setup.   

As above use some kind of knock detection,   and some small base timing adjustments maybe enough.    

With the higher compression it will more likely want to knock.   but the best answer isn't retarding the timing.   Throw some decent fuel in it.  98 or at least 95.

cam may screw up the vac advance a little if its fairly aggressive. which will give you less advance at cruise.  but again  try it before spending the money on another setup