Fri 28th Feb 2014
After the dyno running-in and set-up of the engine, Steve and I both thought all we would have to do is insert the engine back in the car, connect everything up and away we go.
It didn’t quite work out that way, there were a few snags, but Steve and Dave thankfully sorted out the last few issues and I headed up to Wembley on a cold and wet Friday afternoon to pick up the car.
In Part 12 – I explained that there was a problem connecting up the oil pipe from the engine to the new (later) external oil cooler system as it was snagging the 901 gearbox clutch mechanism.
Steve had a new flexible oil pipe made up and fitted it. This allowed the LH heat exchanger, silencer etc. to put be back on the car, then it was ready to be fired up. Unfortunately, as soon as the engine started running – fuel started leaking from the front and rear flexible fuel lines and to add insult to injury the fuel pump stopped working after just a few seconds!
The leaky fuel lines were not a surprise – I’d already asked Dave to replace them as they were old and knackered and had leaked a couple of time previously requiring me to cut and shorten them. The fuel pump (under the front mounted fuel tank) however was a bit of a pain as original type replacements are expensive.
As this pump is hidden up-front under the metal plate protecting the pump, front suspension and steering – Steve and Dave quite sensibly opted to fit a later, better and cheaper 3.2 Carrera unit. Unfortunately however – the new pump required an additional union to link up the fuel lines and tank. The pump was obtained easily enough but the union was frustratingly slow to be delivered.
Once sorted, the car was fired up again and final tuning and adjustments were made before putting the car through an MOT test (as this had expired some time back). Whilst the car sailed through MOT test, some more niggling problems came to light. I was really beginning to think my car was jinxed.
Whilst not show-stoppers – these latest problems would need to be addressed and they included:
- Leaky screen wash tank (replaced with a new tank & pump)
- Dodgy rev counter (replaced with a spare whilst mine is fixed)
- Hand throttle not working (fixed)
The screen wash tank had been leaking through a hole or split in the tank wall part-way up the side of the tank before the engine rebuild but I’d forgotten about it as it still held some fluid but it was best to replace it rather than have screen wash swilling around the front boot compartment.
Why the rev counter and hand throttle stopped working is a mystery. I can only assume the car was in an almighty sulk through lack of use! Anyway Steve had to tidy up wiring for the rev counter but in the end he couldn’t get my rev counter working and he had to fit a spare unit so that mine could be sent away to be fixed properly.
Steve was away delivering a car to Germany but before letting me take the car away, Dave explained the remaining issue. Whilst the car was running ok, they’d run out of adjustment options to balancing advance against revs at idle due to the limitations of the original distributor in relation to the now higher compression engine. He advised that I would definitely need to invest in a replacement “dizzy” sooner rather than later in order to unleash all of the additional engine power. I’ll aim to get this done after I’ve driven the car for a while and it’s loosened up a bit.
The North Circular Crawl!
At long last I was able to drive the car home but it was bitterly cold, it was getting dark, it was raining heavily and I was about to join the busy Friday evening rush hour traffic on the North Circular Road.
I drove away from Jaz around Wembley Stadium and pausing only to fill-up with petrol I pressed on with some difficulty as the revs at idle were very uneven, causing me to fiddle around with the hand throttle to prevent the car from stalling. My over-zealous throttle fiddling combined with the cold/wet conditions and heavy traffic weren’t an ideal combination but I crawled my way around the North Circ and got home safe and sound.
Sat 1st Mar – Find Me Some Open Road!
The following day dawned with the promise of much better driving. The weather was dry and bright if a little cold – perfect for a blast up the motorway to blow away the cobwebs and get some miles under my belt.
As I headed North up the M1 – the car seemed to improve with each mile and what was initially going to be a short run got longer and longer. At Junction 15a – I turned off West onto the A43 passing by Silverstone and headed towards Oxford before turning down the M40 back towards London.
The engine felt stronger and more willing with each mile and at low revs it was surprisingly more quiet than I’d envisaged but I realised that this was helped by the near silent new fuel pump when compared to the whiney, rattley old unit. With engine on cam however and with the dyno proof that the rev limiter was working – the engine made a sublime roar above 4,000 rpm!
As I re-entered London from the West and hit the slow moving city traffic it was apparent that the long run had thoroughly warmed things up and settled the distributor down as revs at idle were steady and at a sensible level with none of the hunting experienced the previous day.
I will need a new distributor as tuning of the engine can’t be optimally set-up with the old one but at least the next few hundred miles before I take the car back to Jaz should be a lot more fun. Steve has advised that I put 1,000-2,000 miles on the car before taking it back in for an oil change, a new distributor and a re-tune.
Steve has recommended a new fully electronic “dizzy” from a Dutch company called 123Ignition (www.123Ignition.nl) . Looking at their web site they offer a range of modern electronic dizzys for quite a wide range of classic cars. For Porsche the web site only shows dizzy solution for 4 cylinder engines (e.g. 356 and 912) but Steve has successfully fitted 6 cylinder versions into a couple of 911s recently.
123Ignition can build up a fully programmable version or a fixed programme based on the optimal advance curve. Steve will use data from the dyno run to define the optimal dizzy setting for my engine so that’s another advantage of having used Neil’s dyno service.
Anyway – I still have to cover a few more miles to loosen-up the engine during what is an extended running-in period before taking the car back to Jaz. By the time I do that Steve will hopefully have provided the advance curve and other details to 123Ignition to build up my new bespoke dizzy. Once this is fitted and the engine is more optimally tuned – it should deliver a further step change in performance and driving pleasure. I can’t wait!