Spitfire bits and bobs

Well the ignition system lasted all of 200 miles before it failed. however the problem was easily tracked down the case was live with 12vdc when this shorted out it cut the ignition out. The fix is in progress and will be refitted to the car soon.

Other stuff that has been done is chase down the leak in the inlet manifold and seal the exhaust. Whist i had the manifold off the car i fitted non waxstat jets to the carburetters. This was not entirely easy as i had to modify the linkages slightly. All went together easily but i still have a high idle speed, looks like throttle spindles are next on the list.

As well as this i used the opportunity to fit the 02 sensor to the exhaust manifold, the gauge now works and without to much fiddling i now now that at idle the car puts out %3.0 Co and is slightly lean on full throttle. I will leave well alone until after the cars MOT and then tweak some more.

The last news is that i bought engine and radiator valances off an Ebay seller, it was spur of the moment but at least it one job i can now finish. The radiator valances i have made will be put on ebay once finished.

Spitfire Electronic ignition part 5

The ignition unit is now finished and working. I'll have to use the car a bit to see if it;s reliable. The finished picture is shown below. I will add a picture in the car soon.

There were a few teething troubles which were caused by my lack of ability more than anything else. I fried a total of 3 transistors, 1 diode and 3 resistors. Oh and gave myself a 300v shock bonus !

The other thing i noticed was a poor spark on the conventional points system. One new 12 volt Bosch blue coil helped no end. Should have done that sooner. what an improvement !

I still have a few tests to run, like shorting out part of the PCB circuit and seeing if the 300V rail drops when the spark output is at 1000 sparks per second. Now a thousand sparks a second is something to see and hear i'll try and post a clip at some point.

Another job is to reset the ignition timing as it probably a little out, a job for tomorrow.

However my main concern is reliability, to this end i'll keep the old coil and ignition module in the car for a while.

Driving

Oh my god new coil + new Ignition module what an improvement. Better idle, less choke. revs quicker when you blip the throttle and no hesitation either. BHP / Torque has also been improved especially from 3000 RPM onwards. I used to struggle to get to 70MPH but now it get there easily. It make the spitfire an altogether better experience. If it lasts i think i'll call this one job done.

Or will i there is a option to increase the output from 45mJ of energy per spark to 110mJ per spark. Now i probably don't need it but curiosity might get the better of me. I would have to rewind the transformer add another zenner diode and 1uf capacitor. that would give me 375volts and double the stored energy. all this equals bigger spark.

Spitfire Electronic ignition part 4 !

Oh dear did i say i would leave this subject, well that did not happen. When trawling the Internet i found a design for a multi spark discharge ignition. this appears to be similar to some the the MSD ignitions. I reasoned that i could make the PCB assembly myself for a fraction of the cost of the MSD system.

So the good bits are i think this will be the best ignition to date.

The bad is that i will have to make a PCB board solder the bits on and get it working, None of which i have done before.

The PCB was the first challenge. Using the front cover of a magazine, a laser printer and bits from Maplin i was able to make the PCB. Beware if you are going to do this as the chemicals involved are not nice. For that reason i will leave the actual details out from this post. However if you still want to try it contact me for the details.

As we speak i have nearly put all of the components on the PCB as per the pictures below, the rest will hopefully go on next week and i can give it a go.

Other things that have been happening - The interior of the car has gone back in and The gear lever has been shortened as per the pic below the new gearbox has now done 400 miles so I'm calling that project Done at last! The stereo has been fitted as per my wife's instruction so i had to find a place for some speakers.

So where do you fit speakers in a spit? I finally ended up making a place behind the seats as per the pictures below. The boxes are 18mm MDF with some Alpine speakers picked up from Halfords. Now all i have to do is cover the MDF with carpet and i can call that job done as well.

Yet another job started is the front Radiator valances, I pick the ally sheet up some time ago but have yet to get to start the job however i finally made the valances. They are not fitted yet as i will need to tidy them up and paint them. That will have to wait for warmer weather before i complete it. I will also have to make the engine valances but the material i bought was to small. um bugger! When i find some more ally sheet at a bargain price i will buy it for them.

Electronic ignition part 3

I have now picked up the dizzy sensor, looks good at the moment i will wire it into the car once i have driven it a bit more.

One thing that will become an issue is the trigger magnets are moulded into the rotor arm. once this wears out i would have to buy another complete dizzy kit. However when this happens i will mod the rotor arm so that it locates on the cam in the dizzy and refit a standard rotor arm on top. Should work but I'll think about that when it needs doing.

I've done this due to the rotor leaving an additional 0.5mm gap from the rotor and the dizzy cap, it didn't work the sparks weaker. It did however let me get the phasing correct. It was about 6-10 degrees out from the standard setup.

As for the dizzy sensor the supplier warned me they have a lot of returns for dead units when people fit them to Quote kit cars. I think that probably means they get blown by the sort of wiring you find on many classics that overpower the coil on engine start. However more investigation seems to suggest that the unit should cope with the extra amperage of this type of wiring. Or at least the unit i have bought can. The unit has a transistor for the switching part which from the data sheet can stand 15 amps continuous load and 30 amps peak.

Anyway for my application it matters not as the electronic ignition unit stops high current going to the dizzy sensor.

I have now tried the electronic box and WOW what a difference the car need half the choke on startup and doesn't bog down like it used to. Best £13 I've spent on the car. It doesn't seem to increase power but refinement and throttle response are immeasurable better.

As above the phasings not that bad. So where do i go from here. Well the coil is now suspect so i will change that use the electronic box with a new set of points and leave it at that for now. I need to finish putting the interior in the car and play with the lamda sensor project.

This will then lead nicely into carb tuning and the dreaded MOT time - Joy. Electronic ignition will be looked at again when I'm not in the potential firing line of redundancy at work.

Spitfire Electronic ignition Part 2

Well Ive got the vellman unit and soldered it up in standard form. I have now connected it to the car as shown below.

Not quite the perfect installation but good enough to try it out, the reel of PTFE tape is just the insulator required. I will need to box it, and i will most likely pot the PCB to stop ingress of damp that could kill it. I will also change the connectors for lucas type connectors and clip the unit properly to the top of the coil. Hopefully it should look like it has always been there once i have finished.

So does it work, of course it does, but it has got a comedy effect. Since the vellman unit is standard i cannot use the straight 12v feed from the ignition switch. The car starts but only when the ignition switch is turned back to normal running mode. At this point the engine is still spinning so starts. if you keep turning the key it won,t start. I sort of guessed this so no problem.

It didn't help that i wired it to the car incorrectly Doh. definitely works now. Also it appears to work ok with the full 12V feed on startup.

Apart from this low RPM running seems more stable and reving the engine is better, the exhaust note has also changed slightly. Performance on the road does not apear to be any better but it's early day on that from.

The pcb stays very cool so it is not getting near overheating so once i have used the car for a longer run and am satisfied that the unit will work i will reconnect the 12v feed and see what happens. At this point my guess is that it will work ok, we will see.

Once i have done 50 plus miles and 20 or so starts from hot and cold i will introduce the electronic dizzy module to the mix. After that a nice high powered coil will complete the package.

Spitfire Electronic ignition Part 1

I've been looking at electronic ignitions and there various merits.

Lumenition - loads around, expensive and plenty of rumors of failures.

MSD - the daddy of ignitions but v expensive, good selection of good high powered coils.

Magnetronic and similar in dizzyunits - Take care of spark scatter but are generally limited to coil switching capability of 4 A. The exception is Aldons ignitor 2.

So where do i go next well the answer is i would like the MSD setup. However i have found i cheap source for a dizzy sensor. for £12 delivered ! amazing as the nearest competitors price is £67. Now the drawback as stated above is that it can only handle 4 amps.

I have just seen a report on the no brand module i have bought, there might be an issue with phasing of the rotor in the dizzy- i will check it out when it arrives.

The solution comes in the form of a Vellman kit supplied by Maplin. This is meant to make point setup last longer by not putting the same amount of current through the points. The dizzy module works in the same way as points so no problems. The only issue is the 4 Amp one.

The clever bits is that the kit needs to be assembled and some components changed To cope with a higher amperage rating. In all fairness Vellman say that there kit can handle 4 amps the components are rated to 10 amps. Now they must have tested there units and concluded they need the extra headroom. So i will follow suit i need 8 amps capability so i need to respec the vellman unit to cope with nearer 20 amps.

The reason for going to the effort make these changes are so that i can keep the standard Ballast resistor circuit. Simply because a boost function for better starting is definitely the way to go.

If this works i will be offering for sale complete systems for use on lucas 45 and 25 dizzys.

So at the rate i work that probably never ! DOh

Gearbox back in again

Well i got the engine out over Christmas, the spigot bearing was damaged slightly. Apart from that there was nothing wrong, so the noise i heard was - Drum roll don't know. I've done about 15 miles and all is fine. Wilst the engine was out this time i made a baffle for the sump to help with oil surge, Don't know if this is going to work yet need better days to get the car out and drive it.

The speedometer is sorted and works well, i just need to add a bracket to the bellhousing to support the speedo cable.

I'm just tidying up the build now, getting the gearlever correct, replacing all the wiring,sealing the engine cover and a load of other small jobs and i hope i can call this one done.

Over and above this I've got caught up in the technicalities of ignitions and that where the next challenge lies i think.