1973 2.4T CIS Restomod

[AndrewSlater]

Really enjoying this thread - one day I'm hoping to have a painted shell returned myself ready to fit all those shiny parts to.

I wondered what disaster could possibly be around the corner...?

I'm guessing it is the CIS engine

[shoestring7]

While all this was happening, the gearbox was sent to Jez at Carrera Performance for a rebuild. It was producing no worrying noises, but 3rd gear synchromesh was tired. It needed very little, a couple of synchromesh rings and the usual bits and pieces, and I escaped with a bill of just over £1,000. The condition did tend to suggest that the 90,000 miles on the odometer may well be a true representation of the car's mileage.

I'd flip-flopped about engine plans since I got the car. The 1973.5 CIS engine was produced in a very low state of tune; it had very small inlet & exhaust ports, soft cams, iron barrels and the pistons are oddly shaped to suit the early generation CIS system. Its very easy as an everyday car, but for a weekend hot-rod it disappoints; at 5,000rpm, just as you expect a bit of a kick, the motor throws in the towel and needs another gear.


Cast iron barrels & lumpy pistons

My options appeared to be to replace it with a later SC or even a 3.2 Motronic lump (at one point I even advertised the original motor on here), or rebuild the existing lump - the one that it was delivered with.

Yet while a later 3.0 or 3.2 engine would add a load of reliable power, there's always the risk of bork with a used engine that could well be 30-odd years old. And if I was going to have an engine rebuilt (I'd decided that doing it myself was too high a risk) I may as well stick with the 2.4 - it has the desirable 7R case and the 'T' engine's low state of tune usually mean the cases are in good condition.

So I got on the phone to Nick Fulljames and ordered one of his twin-plug and all-the-bits screamers.


Not.

My original budget had taken a real beating, what with funding ice driving japes 'n'all*, but I started scraping together enough to pay for a much more basic build - I was hoping to get away with around £7k, assuming no further disasters.

Bad assumption, but it came from an unexpected area. Remember the 964?


It was a superb, low mileage (32k miles from new), example that had had thousands spent by previous owners to keep it in top running condition, and hailed from the era of bullet-proof Porsche engineering.

It did this:




It ran a main bearing. The diagnosis took a while; luckily I picked up an odd rattle at part throttle and stopped using the car. It took from late summer until the strip down in December to finally confirm the prognosis, the end result being that my 2.4 engine rebuild budget ended up disappearing.

C>
*Just kidding

[impmad2000]

2.2s piston and barrels, head work or swap to fit nice big valves, E cam and throttle body injection. You may be able to leave the bottom end until another day (??)
Just an idea, and what I think i'd do.
Tim

[jamie]

LS1 swap

[Gary71]

Electric...

[911hillclimber]

Stroked Impreza turbo.
600 bhp with ease and tons lighter than anything.
Short as a 912 engine, but would need a good box.
You would even have a good heater.

[shoestring7]

Progress over the winter of 2015-16 was slower. Partly this was the hiatus caused by the 964's engine woes, partly because the garage in my house was barely had big enough to let me slide sideways around the car once it was in. I had to wait for fine days to be able to roll it outside. Luckily down on the south coast we have a few.

I sold the 1976(?) dash that was in the car when I bought it. Sadly at the time a correct new lhd unit was wasn't obtainable for sensible money, but luckily Garry 'T-Bone' Hall was able to find me a suitable dashboard. It had several splits in it; the idea was that I'd fill and repair the cracks, and Garry would try covering it with hide:


I'm sadly lacking in packet shots, but here are a couple:

Handbrake cable supports:


Handbrake switch:


I became a regular at the parts counter of my local OPC in Portsmouth. Porsche's support for these old cars in incredible; very few parts aren't available at a price, and its something we should be grateful for. I can remember trying to buy a brake master cylinder rebuild kit for a 10 year old Lancia in the past, and the guy at the dealership just laughed at my naive optimism.

Most of the dash complete, floor seams sealed and sound-deadening installed:


I might have overdone the sound-deadening, but it makes a big difference:


Heater boxes cleaned up and painted:



Heater and tank fitted:


We (by which I mean Garry and Mick) decided that we might as well strip the motor down and see what we had:


Another stroke of good luck; it was all in good condition. Heads and valves could all be re-used:




Much time was spent peering into the engine's depths:




On the engine front I flipped between options that included chucking a match at the thing.

But little did I know, the badger boys had come up with their own plan......

C>

[shoestring7]

So there I was, I had ancient 911T engine in pieces but looking basically sound, and self-destructed 'bullet proof' 964 engine also needing an engine rebuild. And a budget that would just about cover one or the other.

I've met some great people through DDK, but Mick Temple and Garry Hall are paragons. They put their heads together and came up with a proposal. If I bought the parts we needed, and did all the running around, they would build up the engine for me - it would be Mick's first full re-build, but he'd have the more experienced Garry looking over his shoulder. What could I say, but a grateful "Yes"!

The build took place over the spring and summer of 2014.

Everything we could see suggested the bottom-end was in excellent condition.


So after much debate we decided not to split the cases.

I had the heads cleaned and loaded them into my trusty GSA's panniers for the trip up to John Middleton in Banbury for some attention. He's a fascinating bloke; he worked in F1 building DFVs for Frank Williams before starting Competition Engine Services. He also did freelance work - including for BMW Motorrad when they had bearing problems in their early 1200 8v twins. His home workshop was re-assuringly clean and organised; precision measuring equipment was neatly stored on shelves and a flow-bench sat in the middle of the floor.

BMW R1200GSA, with a Middleton sorted bearings!

...with panniers suitable for 911 engine bits.

He blocked the CIS injection ports with alloy dowels that were then machined smooth:


And replaced the valve guides (the valves - which are common to all '73 cars, including the 2.7RS - could all be re-used).


Inlet and exhaust ports were opened up to 36mm 911S specification from the original 32/34 and cleaned up:


I can't remember the exact numbers, but when tested the heads flowed significantly more air once he'd finished with them:


Meanwhile, the CIS system went in the bin and was replaced by a shiny new set of PMO carburettors:


From Kokoparts in the US I ordered a precision engineered* big bore kit comprising 86mm JE pistons and Biral barrels.


Once installed, they should push the compression ratio up from 8:1 to nearer 9.5:1, and increase swept capacity from the original's 2.35l to nearer 2.5l.

Build underway:


And the completed engine, complete with newly powered coated (but original) tinware ready for installation:


Meanwhile I was hard at work on the rest of the car.

C>
*This might not be an entirely accurate description......

[murph2309]

Cool update - looking really good

[shoestring7]

So while the Badger Boys looked after the engine, I spent the spring and summer working on the rest of the rebuild.

I got my two sons to spend some of their Easter hols on some bling. I'd found an original alloy grill to replace the plastic IB one that was on the car when I bought it:


The old shonky black headlining was now a lovely white one:


I had a bit of help!


After a good wiring, I sprayed a load of Hi-temp paint on the headers:


Now the headliner was installed I could fit the sunroof - it wasn't an easy job - and I hadn't even got to re-installing the liner which was a pig. When I bought the seals from Portsmouth OPC the parts-counter guy asked if I really only wanted one set. Apparently when their own techs had restored an early car they got through three sets!





There's no datum point, so you end up placing the various parts by eye. In our case Boy#1 had a slightly different view to me on what looked sensible - shame as he was doing one side while I did the other, so the seal is a little uneven. One of those things I notice while hardly anyone else does.

It raises an interesting point. In an amateur (and I claim to be nothing else) 911 restoration, most of the tasks you undertake are done for the first time. You make mistakes, some obvious, some not so, and all that trial and error takes time. Its where a professional, repeating each operation time after time on various cars, has a huge advantage over us beginners. As I was to find when it came to installing the blasted oil cooler.....

Meanwhile I fitted the doors.

The driver's side always was a better fit:





As mentioned above, I decided that as the engine was expected to generate considerably more than its original 130bhp, I would fit an oil cooler - a later Carrera 3.2 item. It's another decision I question in hindsight; in normal UK temperatures the additional cooling is rarely used on the road - certainly I hardly ever found the hard pipes had warmed up even after motorway usage.

It was also as expensive exercise, the hard pipes aren't easy to come by, I needed a costly new bypass unit as the alloy threads on the used one I bought were corroded beyond use, and it took me several iterations of flexible pipes before I finally sorted out the engine-end of the pipework (thanks to Nick Moss for that tip).

Looks pretty cool though!

Trail fit, the first of many!


>C

[lamakdaddy]

What a truely yummy colour

[shoestring7]

I guess that when you're working on a long complicated project* like a 911 restoration you should expect one complete and utter balls up. This was mine, and it was fitting the oil cooler.

First I flushed, cleaned up and POR15 the oil lines, and fitted them under the car. I expected to find the captive nuts for the (expensive) Porsche set-screws I bought on the car but they were absent, and I had to use a suitable large set-screw instead.


Shiny new oil bypass:


I confirmed that the Carrera 3.2 cooler fitted without cutting the battery box off - I had the cooler flushed and pressure tested before using it.


New flexible lines at the oil cooler end:


I had many attempts to knock up a bracket to mount the top of the cooler. This is the mkIV:


The problem I found was the tight clearance behind the headlamp bowl and above the wing - which I trial fitted many, many times. This was the mkVI (or maybe the mkVIII):


With the cooler and shroud in place, access to the headlight wiring was impossible, so I had to fit that:


I had spent weeks messing around with this thing, and it was the end of another long frustrating day with a deadline looming. So when the fit of the screen end of the wing where it bolts to the scuttle was still miles out I should have just rolled the thing back into the garage and sat down with a cold beer.


Instead of that, I decided to give the thing one more little tweak. There was a sickening moment when the b&stard tip of the b$stard wing suddenly gave way, and I was left with a bent car.

B@stard.


>C
* For a complete novice

[hot66]

Ouch

[shoestring7]

While licking my wounds after having added a bit of unintended 'patina' to the car, I pressed on with other stuff.

The engine shroud got a good cleaning:


Under the car, the front suspension, rack and brake lines went in, along with the cover:


Oil tank, engine cover hinges (and lightweight Rennsport stay ) installed, along with a new engine bay heat shield:


Garry 'T-Bone' Hall supplied some leather off-cuts that I used for the A and B pillar trim. Using leather, while not original, is a good tip for these parts, it's flexible enough to stretch to a nice smooth finish around awkward edges, and takes contact adhesive well.


Meanwhile I had a vision for an interior design that was a combination of 911s old and new. For quite a while I'd been kicking ideas around with a talented trimmer, Joe Clarke at Trimdelux in the South Coast. He does a lot of superb work for the VDub custom crowd, so is open to non-original ideas - and he doesn't charge a Porsche tax.

Here's the stitching on the Prototipo Joe re-covered for me:


I took the seats and rear trim down to Littlehampton, and we agreed a plan :

My pair of Recaro Sportster CSs; probably the best car seats in the world?

Rear jump seats:


Rear 3/4 trim; it would need repairs to the substructure where a PO had installed bangin' soundz:


Working on the trim? The end of the build was in sight - surely it would be all down-hill from here......?
>C

[DustyM]

I sense an impending kick in the balls....