The car was still not running correctly. The car started fine and pulled strongly, but the crankcase was clearly being pressurised and there was a noticeable change in the tick-over when I disconnected the oil breather.
After 1000 miles I changed to a 20w50 Valvoline in the hope that thicker oil would prevent the excessive oil consumption.
When I pulled them all of the plugs were like this:
My hope was that the thin semi-synthetic oil in the engine, plus the clearly over-rich jetting was causing bore wash, preventing the rings from bedding into the bores correctly.
So next I booked a session with an engine tuner that was recommended to me. Based between Petersfield and Winchester, Tom Airey has been tuning cars since the 1970s, and certainly knows his way around a set of Webers (or PMO's excellent Weber derivatives!). While I was waiting his next customers arrived with a vintage Alvis that needed its SUs balanced!
Tom spent a couple of hours changing the jets; somehow the car had ended up with a mix of sizes, partly I suspect due to the previous specialists' efforts to deal with the oil fumes breathing into the carbs.
Pick-up was much sharper after this session, and fuel consumption improved from the ridiculous to the extravagant. I ran through a running in programme once again, but oil consumption was still heavy, and removing the air-cleaners revealed the bases were swimming in a black oily mess
The ride-height turned out to be a little on the low side; the front arches fouled at full lock and 'speed' bumps were an ongoing hazard. I took the car to a local chap who had an optical suspension set-up system and claimed to have TB 911 experience. We agreed to return it to factor settings.
I'm still not sure what settings he used, but I could have ran the car on the Paris-Dakar rally:
The suspension specialist and I had a word, and his second effort was an improvement.
Meanwhile I worked on the oil-lines. The first effort using Carrera 3.2 lines ran into clearance problems around the driveshafts so I had a flexible hose made up that ran from the oil cooler to the bypass unit:
But there were still clearance problems, even lifting the lines as high as they could go:
Eventually I discovered the solution; Porsche created it for the '74 2.7 Carreras which used the mag cased engine with a cooler. Its this bit:
The mk2 and mk3 lines:
The mk3 lines successfully installed:
The issues I had here are, in my experience, typical when you move away from a standard spec. rebuild. While frustrating and costly, I fully expected to have to undergo a bit of r&d with the car. At least I was able to call on the resources of DDK for assistance, and it was Nick Moss of Early 911 who put me on the right track.
Meanwhile the car failed its MOT
Partly that was down to me being a Richard Head and failing to tighten the steering rack bolts properly (again
) and partly the MOT inspector being a Richard Head and insisting the car required two door mirrors. It didn't. Re-presented with the rack fully tight and waving the appropriate age-related exceptions in the inspectors face, it breezed the re-test.
I was after any second opinion I could get, so when Jonny Hart contacted me offering to let me try one of his replacement Classic Retrofit CDI+ units I jumped at the chance. He was looking for an early car to try a unit in, to ensure any installation issues were fully understood before full production started.
Jonny busting a knuckle or two fitting the CDI+ box:
We spent the afternoon buzzing around his lovely part of Sussex. Certainly the car appeared to pick-up better, even if he commented that it seemed to be down on power compared to what he would expect. Eventually we agreed that I would run the unit in the car for a couple of weeks and report back (In hindsight he was right about the power; I'd noticed the engine note had changed but put this down to the exhaust bedding in. It turned out to be a head gasket on the way out...).
We're still not really sure what happened next. Half an hour after leaving Jonny's I'd just reached the M25 when the car started cutting out. This happened in fits and starts, sometimes it ran fine for several miles, but would then cut out several times within seconds. Each time the tach swept the dial as the CDI+ box re-set itself, and the engine re-started. This was bad enough cruising in top, but in stop-start Friday evening traffic on the M25 it was frankly a complete nightmare. Eventually I got the thing home, parked it up, shut the garage door and had a very stiff drink.
I couldn't fault Jonny's after-sales service. We exchanged emails and phone calls, trying various solutions, and a couple of weeks later he even came over to see me (by this time I was staying in Ascot) to try a software update and new cables. The problem appeared to be caused by an earthing fault, something the original factory CDI box would have been less sensitive too. It was pretty frustrating for both of us; and eventually we could only agree that there must be an underlying issue with the car that was causing the problems. I packaged up the CDI+ 'box and returned it, on the basis that we'd have a re-match once the car was sorted.
The garage doors stayed closed for most of the winter while Garry, Mick and I debated an approach.
Eventually we decided we had little option on the next step. One warm Saturday the following April we did this:
Next step was to take a look inside the engine and see what we could find....
C>
):
Jez struggled a bit with the carburettor settings, but as the rings hadn't bedded properly the engine was breathing a little heavy:
, and reluctantly agreed with the conclusion - it had to come out and stripped down to see WTF was going on.
