70 S, RHD, Signal Orange, UK->Australia->UK

[inaglasshouse]

Looks like you might have a little problem there Richard, reminds me of Darrens similar wheel issue.....

Hi Mark, ha, yes, I fear I do have a bit of a headlight habit.
Not only Biodes.
Cheers, Richard.

[Tp81]

A couple of pics of the finished dash. With many thanks to Garry (classicfx on DDK).

Looks lovely

[stretch]

Good solution to the turn signals Richard. Will update my own thread in the next week or so. You are welcome to visit anytime.

Dave

[inaglasshouse]

I'll try not to spam DDK with every little bit of progress, but perhaps this is useful to someone:

For the steering column lower bearing ('70 car - later ones were different I believe), Porsche used a bearing that is shielded on one side, and fitted it with the “open” side upwards. Over the years mine had filled with various detritus and was very crunchy. Cleaning helped a bit, but the proper solution was a new bearing shielded on both sides.

Happily Porsche tax does not apply to generic bearings, so it cost me 3.46 GBP (including VAT and postage) from https://www.bearing-king.co.uk.
I needed a 6003-2Z FAG Shielded Deep Groove Ball Bearing 17x35x10mm

Purchases like this are, for me, the antidote to the endless 50 quid trips to the OPC to get the small handful of grommets / screws / little plastic clips / magic beans that I can't find elsewhere. In the case of this bearing I am genuinely baffled how they can make it for that price.

It's held into the housing with a circlip, and another circlip keeps the shaft located in the bearing. Five minute job to change it while the column was out, but I think would also be do-able in situ.

[hot66]

don't worry about overloading us with details. Its all great stuff

[inaglasshouse]

Decent few hours on the car today.
With no swearing or bloodshed at all, I finished off the repair and testing of the fore-aft loom.
Then, with a large amount of swearing and moderate loss of blood, I managed to get it fitted to the car. Threaded into the tunnel from the back and pulled forwards, as you all know. Not fun, but a nice job to tick off the list.

[stretch]

Good result Richard. Little and often..

[inaglasshouse]

The next part of the electrical sort-out was the panel in the engine bay. The one with the CDI box, rectifier, couple of relays, "speed switch" etc.

Here's what came with the car:

Let joy be unconfined. Pretty sure some of that wiring is non original.

Today it looks like this, which is quite nice but not the interesting part....


The interesting (to me) part is that I'm using a CDI+ box, having enjoyed good results with the one in my 69 car. Stealth version, built into a Bosch original case.
I'm going a step further this time and locking the distributor, so the CDI+ is responsible for the advance curve.

[inaglasshouse]

For my car, the distributor is a Bosch 007.
Standard advance curve for that is:



It's pretty easy to get the same curve into CDI+, as a starting point:



Please ignore the deliberate mistake - I've gone beyond the available adjust room for the amount of initial physical advance (hence my curve goes into the red area of the graph). I took the screenshot before I'd finished fiddling about.

Note also a few useful bells and whistles. On my other car I particularly like the soft limiter - much more civilised than the all-or-nothing mechanical limiter (spring in the rotor arm).

[inaglasshouse]

Speed switch, no more

As you know, the MFI pump has a solenoid which operates a fuel cut off. The principle is that, on a trailing throttle at higher revs, the unit stops pumping fuel into the engine. Anyone who has followed an MFI car on which it's not working (fairly common fault) will recognise the bangs, pops and occasional flames. Quite cool, but not especially good for the engine.

One component of the system is the "speed switch", which detects when the revs are above approx 1500 rpm. Above that level, when the throttle closes (detected by a microswitch), the MFI solenoid should energise and the fuel shut off. On the way back down the revs, below 1300 rpm the solenoid needs to de-energise to resume fuelling and prevent the engine from stalling.

The CDI+ offers a (programmable) replacement for the speed switch.

There's a wire coming out of the CDI+ box:



Which needs to be connected to the microswitch + solenoid via a 40A relay, thus:



40A relays are readily available. Mine is a nice little grey Hella one which should really live in a Skoda:



I know what you're thinking, that looks crap and why did you choose that ugly relay?
Answer: because it fits into an old speed switch case. Stealthy:



Output programmable via the CDI+ software:



I've tested the microswitch and solenoid, all fine, so I reckon we should be in good shape for working fuel cut-off.

It's all plug and play, no butchering of the loom required, so could easily revert.
Thanks to Jonny (DDK-er and owner of Classic Retrofit who make the CDI+) for the help and exemplary technical support.

And that, in a nutshell, is the kind of mod I'm doing. Criteria:
- Easily reversible
- Makes the car work better (higher performance or more reliable), or look cooler
- Does not change the character of the car. A 2.2S is fine for me. In this case the way it feels (apart from the soft limiter) should be exactly the same as an MFI car on which the CDI, coil, distributor and speed switch are all working perfectly.
- Aesthetically hard to detect, or deliberately different in a way that I think looks better.

[DustyM]

Very nice arrangement


Sent from my iPhone using Tapatalk

[stretch]

Clever stuff Richard. I think that's something i need to look into. Thanks for the explanation.

[one-two]

What's wrong with all the popping and banging - the flames look great at night

[inaglasshouse]

Mmmm, lovely flames just like your new Lamborghini, I imagine, Robert.

Realise you probably weren’t looking for a serious answer, but I am not deterred.
Dumping fairly large amounts of unburnt fuel into the engine on a trailing throttle causes various issues. Obviously it’s a bit of a waste of fuel / money, and not great for emissions. I’m more concerned with oil dilution. If / when the fuel ends up at the bottom of the engine, it’s far from ideal for the lubrication. Some oils (inc the racing stuff) allegedly cope better than others with being diluted in this way.

[BILLY BEAN]

Richard,
The older air cooled engines are pretty "dirty" in emissions terms. If anyone was concerned about this aspect of running an air cooled Porsche they would be well advised to find an alternative: maybe a hybrid Aygo? So I think it's hard to make a case regarding unburnt fuel and emissions. Admittedly unburnt fuel will not help emissions and will provide a bit of popping and banging as suggested by Robert. However, as to the amount of unburnt fuel actually making its way into the crank case I am unsure. There is still an ignition spark which should ignite some of the fuel and the exhaust valves are still operational so some unburnt fuel should conceivably makes its way out into the exhaust system and hence a bit of flame. I think Darren's Mongrel has dispensed with the fuel cut off on his MFI pump but I may be wrong about that. Perhaps Darren might comment? I was recently told that on later Pagodas (which used a similar MFI pump) dispensed with the fuel cut off. Maybe someone more knowledgeable than me might chime in? Regards Kirk