964 C2 - Rolling Resto

[rhd racer]

So next to fit the oil pump. Here with the chains attached to the intermediate shaft, you can see the filter in the sump which we blew out to ensure clean. This is your oil pick up, and a slightly different design to an earlier 911 with a sump plate.



So, before we put the crank in I spotted this. Apologies for the terrible photo but it is the only one I have. You can see a big crescent shaped gouge in the middle of the photo, where in a previous life a conrod has met the case. Fortunately it is a couple or 3mm from where the barrel slips into the case, so no harm done.....



The other half of the case with the shells fitted



And then the cases coming together.



Apologies, no photos of the crank lying in one half of the case, but it is a bit time bound this bit and we had a few visitors. The sealant stage is critical (in date, evenly applied with a brush to one surface, assembled quickly), so David Bailey was not a feature of this stage

[rhd racer]

So here is one of my shelves in the workshops - barrels and heads, inspected and all within tolerance, new valves, guides and seats as we know, and a bit of new paint...



Now the case with the new head studs fitted on one bank...



New rings fitted and barrels fitted



This step didn't take long at all. And then heads fitted to the same bank...



Then a bit of a fast forward to the same on the other side. Torquing as always from the middle out, in two stages per the manual. I should say, a recurring theme is having the right equipment, and a really good torque wrench with audible and visual RAG lights made every step loads quicker / easier.



And that is basically how far we got on day 1 (excluding the images of working on his brother-in-laws A6 transmission, various customer visits and this and that!)

Great progress, still daylight, time for beer and the Spanish F1 qualifying!!

[sladey]

Really enjoying this thread

[Bootsy]

Agreed, superb stuff

[rhd racer]

Thanks

So Day 2 started with the Saturday boy (me!) running the cam carriers through the parts washer after the drilling and tapping from the day before. Once done, and blown dry with air, Gus put in the oil drain tubes then set about putting sealant on the mating surfaces. Again, a small amount to just the mating surface on the head, with the cam carrier quickly fitted and torqued up. Same process again, two stage torquing, middle first then work outwards. This needed us to work quickly, not only because the carrier itself is tricky to fit because the studs are quite long, so it doesn't take much for it to catch on a slightly bent one and not go on. Fortunately we were lucky and they went on, after we replaced a couple of studs. You can see the polished mating surface down the middle of each head, and basically this allows oil sprayed onto the cam to find it's way down to the drain tubes before returning back to the sump. Note also the heat shield for the barrels secured by 3 bolts to them.



Then you have to fit a washer on each, and a mix of hex nuts plus 3 allen headed nuts per bank where the casting does not allow you to get a socket on a hex nut (these were standard hex nuts originally when we tore it down, another PITA). After that, it looked like this..



You can see both types of fastening in the image above.

Then, onto the cam housing. The cam has been slid into the carrier, and the LH timing chain is just resting on the end of it for now. One of the plastic chain guides has been put in, but not bolted in (if you follow the line of it you will see a large thread insert in the case, for the allen fastening that secures it. These remain loose until after the cam timing is complete, as it is easier to move the chains this way.

[rhd racer]

And then onto the other side, to the same stage



plus the front pulley temp fitted so we can rotate the engine to do the cam timing and tappets. Note temp fitted because the proper bolts are on back order, replacing the hex nuts mix we had on the initial strip down. This will also be blasted and painted later.

So now the fun begins. Sealing plates fitted to the end of the cams (these have an enormous rubber O-ring that needs a bit of grease so it slips nicely into the cam casing.



Then the toothed cam wheels fitted (I am sure there is a proper word for those). These are fiddly, and why having the guides loose is a good idea because you have to mesh the wheel and the chain together, then slide over the woodruff key on the end of the cam. The nuts are fitted but will be undone many times in the next couple of hours!

[DustyM]

Nice progress. I have to do the opposite tomorrow and strip down a 964 engine.

[rhd racer]

Now the chain guides / retainers / pressure tensioners all fitted up.



You will see the nuts securing the cam sprocket wheel that we don't know the proper name for has been removed. That is because this is a crucial part of the build. Basically, because the engine is horizontally opposed, there is a factory tolerance for ensure that the chains run squarely to each other. In essence, you place a steel rule across the case on a diagonal below the front pulley. You take a measurement from the rule to the intermediate shaft bearing, and then take off the depth of the rule. This gives you the basis for measuring each side. So on the left side, the rule is angled up toward the toothed cam wheel, and a measurement taken, less the depth of the rule) against the outer surface. You then repeat on the right bank of the engine, and then the difference between the two has to hit a very narrow range. If it is out, you shim the toothed wheel with washers; on each there is a shaped space which only goes on one way, and between 2 and 4 washers per side is the norm. My left bank required 2, the right 4, and this brought them bang on to factory tolerance. Pleasing to note that was how we took it apart, so that part of the job was done correctly on the last build. If this procedure is not followed, the chains will prematurely wear.

If you look closely, you will see that the toothed wheel thingys fit in a reverse orientation depending on the side of the engine - dish out on the left, dish in on the right. This offset obviously was designed in to allow the factory tolerance to be reached.


Here is a shot of the most complex part of the whole build, which Gus says sometimes the magic happens on the 2nd go, or you can be messing around for a while. We were messing around for a while.....



The gauge is secured to the cam carrier and has a needle which sits on the valve - it is effectively measuring lift. So at TDC, you are trying to achieve a precisely determined lift (so number 1 is firing exactly at TDC). Then repeat for number 4, though the order does not matter. I can't quite remember the numbers, but I think our target was 1.7mm lift at TDC (plus or minus 0.1mm)!!

To adjust it you can see a small pin with an M5 bolt in it - you effectively pull this pin in and out and into a different hole to adjust your position until you arrive at the factory tolerance. The problem is that if you are close, pulling the pin out can make the cam jump (or really slip) so your 1.7mm becomes 0.8mm, which then translates as nowhere near TDC when you achieve the 1.7mm you need. Following?

The next issue is that the pin will only fit in one hole perfectly at any time, so you need to create slip between the wheel and the cam to get your target hole to line up. Essentially we had slip when we didn't need it, then grip when we needed slip.....

Luckily, through Angus's experience in sensing by the relative position of where we were on lift vs TDC he manage to estimate where we needed to be, and after a few goes we got it. The second bank, by contrast, was achieved on the 2nd attempt in about 10 mins flat.



So there is cam timing in a nutshell. Frustrating, but super crucial for a good running engine. It can be influenced by wear in the sprockets, and we ended up towards the high end of the tolerance on both banks.

BTW - for those that do / have build engines I won't be offended if you point out any errors / provide correct terminology. This was the first time I have ever seen one be put together, so luckily there was an expert in the room!

[rhd racer]

Finishing straight now.

Fit the rockers and set the tappets;



Replace all the rubber grommets and nuts on the cam cover fixings and fit (incredibly low torque setting of just 10NM I think it was)



Then new rocker cover seals and fit the rocker covers



Loose fitted the oil pipe too - this cannot be tightened until the front engine cross member and tinware are fitted so it locates in the right place. Then the heat exchangers can be fitted, but again these need to wait until the previous step is complete otherwise you cannot get to the union.

So this is where we finished at about 5pm. A long block, which we then wrapped in cling film for a couple of weeks until the next visit which will see us build it up with the ancillaries, fit and run up. A pretty good weekend's work.



Hope this all helps. I found it a fascinating process and was surprised at how much I understood of how it worked and why it was designed the way it is, and why certain features exist. There is a lot of work involved, but it all requires patience, meticulously clean components, a good set of tools and a methodical approach.

Huge thanks to Angus at amsporsche (https://www.amsporsche.com/) for all his help with the build. Luckily we have known each other for 20 years so he cut me some slack in holding him up by taking photos at every stage!

Roll on 2 weeks....

[Gary71]

Really interesting to see, keep posting!

[911hillclimber]

Super read Wayne.
I've done a 2.4 and my 3.2 several times and the greatest change is in the cam timing design removing the need for the crows foot spanner on the cam sprocket nuts to simple bolts.
Here the greatest chance is evident as you say in much the same area, the guides and the tensioners, all so much better.
Never knew the covers were plastic, 10 Nm is almost finger tight!

A very good days work and great he will allow you 'in' on the whole process.
My first experience of cam timing was watching Bob Watson doing my 2.4, not sure I fully understood what was going on!
I'm ok now having done the 3.2 several times, the right tools make all the difference.

I lean something every day, never knew you could buy torque wrenches with a buzzer to indicate you have reached the value.
Also, the builder only put a smear across the mating faces where I've always used a small continuous bead of loctite sealer and allowed the clamping action to spread the sealer, interesting.


Look forward to it starting!

[Gary71]

I learn something every day, never knew you could buy torque wrenches with a buzzer to indicate you have reached the value.

I borrowed one from work when I did my engine. Also does torque and angle measurement. You wouldn’t buy one for a DIY job though!

[Darren65]

Just caught up with this thread.....brilliant, thanks for sharing

[rhd racer]

So with this weekend coming around quickly, my mind has suddenly been focused on the huge piles of ancillaries that I brought back from the workshop after the tear down that need cleaning...

Now everything had already been through the parts washer, but was all covered in what I can only describe as a dull, grimy baked on oil finish. It covered everything, and it wasn't quite the look I was after. So I tried lots of things, and landed with a sponge scourer and degreaser. This seemed to cut through the baked on crud, but it was one of those jobs that once you started, it showed up all the bits that were left in the awkward nooks and crannies. So a brass wire brush was carefully used, a screwdriver and rag - you know the drill, I just kept plugging away until the original plastic finish was revealed.

I was feeling pretty pleased with myself, but it took days. With each single effort, it all needed a hose off to remove the degreaser and so I didn't know hat I had until the next time. I haven't taken any photos of these stages, because they would be as dull as a dull thing.

Once I thought I had won the war, I went out to the garage fully of girlish glee (not really, but you know what I mean) only to see this horrible marble finish on everything. It revealed plastic surfaces that hadn't been cleaned for 25 years and it again looked awful. Clean, but awful.

So I tried a small sample with 600 grit wet and dry, and sure enough it cleaned not only any residual bits I had missed in the awkward spots, but also evened out the finish.

Now after my first 2 hours doing this I went outside with a coffee and gave myself a good talking too. This is not a concours car, I am not replating anything, but I want it to look like a rebuilt engine, and like one that is cared for and looked after. Nothing crazy, just suitably clean.

It still needed a bit more, and after a bit of trial and error I found that Autoglym rubber and vinyl produced a decent finish as long as it was wiped off straight away in order to not make it too glossy. The one thing I was desperate to avoid was the look of 'used car bullsh*t spray' that you see on over-prepared used cars

I think it turned out ok...





Note the airbox mods for induction noizes......(I did not do this, but I probably would have anyway, albeit with better alignment of the holes )



I am not joking when I say that this was a real PITA doing the tiny squares, but I was kind of committed by this stage!

It still all needs a bit of a dry buffing at this point, to even out the finish, but it is getting there.

[rhd racer]

The alternator was the easiest...



But the inlet manifold the worst....I think this exhausted 3 or 4 evenings overall.....







The dizzy and leads came up well too. Unfortunately oil kept seeping out of the insulators on the bottom leads (they have a rubber sleeve which slides about by 2-3 inches which I guess are there as additional heat protection). These were just full of oil, and every time I degreased them more seeped out...