Author Topic: Porsche 964 1990 C4 rebuild  (Read 107944 times)

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Offline brian

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Re: Porsche 964 1990 C4 rebuild
« Reply #100 on: April 19, 2022, 01:27:08 pm »
I think EV's might cause a bit of grief to ALL spare parts vendors unless they can charge more for topping up you already full windscreen washer bottle while servicing the car!!!
Škoda Fabia 1.0 TSI Race Blue

Offline Period_Correct_

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Re: Porsche 964 1990 C4 rebuild
« Reply #101 on: April 19, 2022, 02:40:48 pm »
did you use any base shims between the case and cylinders?
...Nigel Aston
1971 Porsche 911T | 1990 Audi Quattro Turbo | 2006 Renault Clio 182 | 2009 Renault Megane R26

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #102 on: April 19, 2022, 08:18:11 pm »
No shims, comp is about 11.4 / 1 from memory.
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline dubstar

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Re: Porsche 964 1990 C4 rebuild
« Reply #103 on: April 23, 2022, 10:04:01 pm »
When I’ve had to buy the odd Porsche part for the mk1 (like the very early strut bushes), I have used https://www.porschepartsbyjeff.com/ to find the best price
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Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #104 on: April 25, 2022, 02:58:15 pm »
Nice, thanks. I've never come across that site.
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline Pristle

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Re: Porsche 964 1990 C4 rebuild
« Reply #105 on: April 25, 2022, 10:44:38 pm »
As I've discovered Porsche and expensive go hand in hand  ;D
I was quoted $66 each for 10mm roll pins just last week by one of our friendly dealers, I said that's just impossible for a roll pin.......(worth all of a dollar or two) but no. That price was correct.

An old neighbour with a Ferrari 308 scour Fiat parts first and only when he draws a blank there does he call the Ferrari dealers. In many cases the box part number may be different but the machine stamp on the parts are the same.

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #106 on: May 01, 2022, 09:38:23 am »
No update last week as I decided to jump back on finishing up sanding the doors, removing the glue on the insides of the doors etc.
These are now with the painter irrespective if I did things right or not they are his problem now. That concludes all of the body work I'm doing and I'm sure it will be many months before I see a painted body back but that's ok as I have plenty to get on with.
Yesterday my friend John came over to help with the engine, he's been through this whole procedure before and did all the research on what sealants / products to use while assembling the engine to avoid leaks as much as possible.
In the last update we did a long block mock up to enable us to check piston to valve clearance due to me installing 993SS cams, also important as I'm now 3.8L

This involved having the long block together but we didn't bother with rings, gaskets or wrist pin clips as it's all coming back apart when we're done.
Setting up the cam timing is a bit of a procedure but once you get your head around it and understand what's happening its actually pretty easy. Quicly made some manual chain tensioners in the morning to be able to pre load the chains.
The cam gears are infinitely adjustable and my cams require 1.55mm lift at TDC overlap this means the piston is at the top and the valve is starting to open for the downward stroke and is as close to the piston as it will ever get. At that point I need 2mm clearance to the piston.
Using the dial indicator we set both sides to 1.55mm and then used the tappet adjustment screws to measure the clearance.
For what ever reason I was fixated on inlets and totally forgot about checking the exhaust valves. In saying that the exhaust valves are smaller diameter so "should" be ok but we'll be checking those at final assembly.
Pitch is 1mm thread on those so one full turn is 1mm, we had very close to 3mm clearance so looks good there.
Tore the engine back apart after that and now have the job of re cleaning everything, assembling pistons, rings, cylinders and preparing the cam towers for final assembly. More on that next week hopefully.
« Last Edit: May 01, 2022, 09:48:46 am by 80 Vert »
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #107 on: May 08, 2022, 09:54:21 am »
Engine build day!! Well, yesterday it was at least.
Got everything as ready as I could with all the parts laid out in order on some fold out tables, works better than lots O boxes of stuff on the floor. Having re cleaned everything after our dummy assemble checking piston to valve clearance things were all set for Saturday.

The wrist pin clips were fun, hence the towels in the engine to hopefully catch any rogue clips from disappearing in to the case itself.
My friend John had an installation tool for the clips which worked pretty well and certainly easier than if one were to try installing them by hand.
Few missed attempts but in all went pretty good, no profanity so I call that a win.


Installed all 6 piston / cylinder / ring sets and most importantly the air guides. Next up are the oil drain tubes and cylinder top sealing rings.
I'm constantly surprised at just how many bits there are to these engines and how many boxes of parts you end up with when pulled apart. I think this engine has been apart since 2019 or so, definitely time to get it together again.


Since the cam towers and heads are a dowel fit I decided to assemble these on the table and then plonk the whole lot on in one hit, seemed easier than trying to line everything up on the engine. Used Loctite 574 sealing compound between the 2 to keep the oil where its supposed to be. I would discover later that I'd need to take all of this apart again.

Heads and cam towers on, beginning the torque down sequence. Copper coat to lube the threads and head nuts for a nice even torque.
What a marvel of engineering this thing is, a real pleasure and privilege to work on.
With all the head nuts torqued down and marked I went back to torque the cam towers to the heads, the very last nut inside the valley of the cam tower wouldn't torque and felt like it was starting to strip.
After looking more closely I realized that when the heads were rebuilt and studs removed / reinstalled they were screwed in too far which meant the nuts didn't have full thread.
Only the studs deep in the valleys had this problem on both sides, even though all but one torqued up this wasn't something I could leave so the only option was to remove both cam towers again.


Took the cam towers off one at a time and just backed the 6 affected studs out a couple of turns making them protrude out just that little bit more. As usual cleaning the sealant off everything and getting it ready to bolt back on took the longest but feels better knowing that part is now as it should be.
New Loctite 574 applied and dropped the tower back on. Funny enough no problem torqueing everything down when there's enough thread!!

Finished up here for the day, nearly completed long block. Cams, cam timing and all that good stuff next week.
« Last Edit: May 09, 2022, 03:04:09 pm by 80 Vert »
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline le mans

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Re: Porsche 964 1990 C4 rebuild
« Reply #108 on: May 09, 2022, 10:14:59 am »
It must be very satisfying assembling an engine. Great to see another classic being saved and preserved.

Offline Period_Correct_

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Re: Porsche 964 1990 C4 rebuild
« Reply #109 on: May 09, 2022, 10:32:51 am »
oooooh... exciting :D
...Nigel Aston
1971 Porsche 911T | 1990 Audi Quattro Turbo | 2006 Renault Clio 182 | 2009 Renault Megane R26

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #110 on: May 09, 2022, 03:02:38 pm »
Indeed chaps, satisfying and exciting. Been apart far too long.
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline dubstar

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Re: Porsche 964 1990 C4 rebuild
« Reply #111 on: May 10, 2022, 05:03:23 pm »
Much cooler than a Golf 4-banger
"I am so clever that sometimes I don't understand a single word of what I am saying."

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #112 on: May 15, 2022, 03:59:44 pm »
Continued on with the engine yesterday but due to a long lunch with friends and a bit of fail on my part didn't get very far with the build, installed the chain boxes, chain ramps and cams.
Got everything together and about to start setting the timing and discovered that the engine would turn so far and start to bind, very quickly realized that the left chain was not sitting on its ramp correctly which as it turns out was caused by the chain coming off half of the sprocket on the crank.
Tried for a bit to get it back on by removing the cam sprocket but that didn't work so both ramps came out making it a lot easier.
Of course the one time use crush washers on the ramp pins had now been used and I did try putting a light smear of 574 on them but that made them too slick causing them to distort when attempting to torque them.
That along with not having the correct allen tool to tighten up the rocker shaft bolts ended the day a little early. Did check the parallelism of the chain sprockets which all seems ok to me.

Not wanting to leave defeated, late in the afternoon I took a trip down to my local speed shop on the off chance he was still there to see if he had any crush washers I needed, success on both accounts. New washers on and torqued to spec no problems.
Everything back together to the point I was at earlier, setting the cam timing.
Didn't much like the amount of variance one can get eyeballing Z1 with the split line of the case so I made a simple little pointer held in place by small grips.

This simple little thing makes lining marks up much simpler, setting the left cam accurately to 1.55mm (Webcam 993SS) took a bunch of attempts but got it in the end. The right cam however was dead on first go.
Literally Z1, pick a hole that fits for the pin and check lift. Couldn't believe it, that never happens. Well, not to me anyways.
My tuner will check all of this anyway prior to first start on the engine dyno as he prefers to set up cams on lobe centers with a degree wheel.
I got a set of RSR seals for the rocker shafts to hopefully stop any leaks from that department.
Not a tremendously interesting update but progress is progress.
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #113 on: May 22, 2022, 09:59:07 am »
Back on the motor, my friend headed over in the morning armed with a couple extra tools we'd need for the job of installing the rocker shafts and rocker arms. RSR seals well oiled to hopefully install them without nicking them anywhere.
The endless potential for oil leaks with these engines amazes me, just so many places these can leak from but beautifully engineered.
Rocker shafts in and torqued, had to cut down an allen key for the two very end ones as its pretty close to the chain housing.

When I set the cam timing last week I tightened the chain sprocket bolts but not final torqued them, I'm certainly very grateful for the loan of all the specialist tools needed to make life easy and to be able to do it the correct way.
An operation that takes mere minutes to do with the correct tool and knowing its 100% done right. awesome.
With those done the chain box covers went on, solid tensioners I used for the cam timing removed and replaced with the stock hydraulic ones.
Oil bridges fitted to supply oil to the cams and spray bars pretty much wrapped up the rotating assembly.


The afternoon turned in to a fit this part, remove it again to fit something else type of affair. Since I never took this engine apart and the fact it's been in bits for 3-4 years didn't make things any easier.
Lots of looking on Porsche PET for part locations, fastener type and length, searching part numbers etc resulted in only a handful of parts being fitted that took the entire afternoon.
I modified the rear A/C bracket so that it can be fitted / removed without removing the rear crank pulley, the way it should have been done from the beginning.
Installed the tinware I had powder coated years ago, fan shroud, new crank position sensor and new CHT sensor also.
Still waiting on new billet valve covers to be custom made, need to make a power steer pump block off and distributor block off as well. With the MoTec we'll be running Audi R8 coil on plug (12 of them.....gulp) and I'm removing all of the power steering gubbins off the engine to run the same electric Opel pump I have in the MK2.

2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline le mans

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Re: Porsche 964 1990 C4 rebuild
« Reply #114 on: May 23, 2022, 10:17:57 am »
Coming along nicely!

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #115 on: May 29, 2022, 10:05:43 am »
With the engine at a point where I'm waiting on more things to be plated, powder coated etc I thought I'd start looking at my bench of small projects to be done. One of them being the rear engine hanger plate.
These are notoriously weak even on standard cars and mine was bent on the ends as well, of course a well known company makes a weld in reinforcement plate at a great price but the usual story after shipping it half way around the world it aint so cheap anymore.
This is why I decided to make my own, I have the tools, materials etc and its satisfying making something from scratch.
Found some same thickness 3mm plate in my shop but I don't have a brake for that thickness so the only option is the vise and a BFH. I tried over the edge of my steel bench but it wasn't having any of that.
Scribed out the steel and started bending the edges over little by little, big hammer helps.


Trimmed to slip over the mount basically boxing it in, makes it far more rigid and supports the ends where the engine hangs from. I'm actually surprised how weak these are. Took no effort at all to bend the mounting eyes back to where they should be.
Marked out the relief clearance for the crank pulley and cut that out taking in to account a tab to support the middle of the cut away.
Bunch more fitting and trimming later its all looking really good and is a nice tight fit.


I wasn't going to bother to drill the holes but did in the end, doesn't really need it and certainly won't really make it much lighter but seems more finished that way.
Clamped it on to the original mount and welded it. I could have tig welded it for a nicer look but the Mig is easy and just as good for something that isn't a focal point. Bit of clean up to be done prior to powder coat.
Test fitted it on the engine along with the rear tin which caused me issues with the 997 GT3 muffler. I hadn't taken the rear tin in to account when making the exhaust all that time ago.
Looks like that's easily resolved though and as it turns out I'll be making new headers anyway due to going 3.8L the ones I have are too small.

« Last Edit: May 29, 2022, 10:09:31 am by 80 Vert »
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #116 on: June 12, 2022, 10:40:19 am »
Sometimes you spend nearly a whole day working and at the end you look and think is this all I did today, yesterday was that day.
Away at the track last weekend so nothing got done and no clear plan for this weekend I ended up doing bits and pieces.
Got some more stuff ready for powder coating, washed out the dry sump tank and plugged as many holes as I had plugs for. There's only one they need to take care of but I'll be thoroughly cleaning the tank anyway once its back, the rest is the remaining engine tin and a bunch of random brackets.

Quite some time ago I had the engine fan powder coated but due to impurities in the magnesium it looked like a dogs breakfast once they baked / heated it. This was even after a pre heat to boil all of that out. Can't be done they said. Bummer.
I decided to use the powder coat that was on it to hand sand the whole thing smooth and just 2 pack paint it. Easier said than done.
Hours and hours of sanding later it looked somewhat better, ready for etch on the exposed magnesium.
You'll never stop magnesium corroding but this will have to do for now.

Took the alternator apart and someone has been there before as the bearings look quite new but since it's apart now I'm renewing everything, bearings, slip ring (quite worn) and brush box. Don't want to go back there once its all back together.
The fan bearing seems really good so I'll just clean and re pack that with new grease.
The fan / alternator ring still had its factory paint on it, blasted that in the blast cabinet getting most of the stubborn paint off.
2 pack etch on the alternator ring and fan to hopefully slow down the corrosion by sealing everything up, light coat of epoxy will be next followed up with some colour.

« Last Edit: June 12, 2022, 10:44:38 am by 80 Vert »
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #117 on: June 19, 2022, 10:21:40 am »
Sunday again already, time for another update.
Rummaged through the left over paint cabinet to see what suitable colours I had to paint the fan with, found some plain silver for the ring and a dark grey from a VW Notchback I painted about 15 years ago. It was going to either be that or Kubota orange (which would look cool too)
Light coat of epoxy, let that flash off and hit it with colour, saves another round of sanding. Wet on wet for small parts like this is actually the easiest way as long as you let the coat underneath dry enough.
Reassembled fan / alternator with all of its plated hardware ready to go back on the engine, once its all together in the car if for some reason I need it to stand out more the blades can easily be removed and painted orange......but I think subtle is better.

Had a fight and a half installing it on the engine, the alternator was clocked the wrong way in its housing and no matter what I did the wiring didn't seem to want to fit and sit nicely. In the end 3 attempts was the magic number and it's now back where it belongs.
The air cooled flat 6 doesn't really come to life until the fan is installed on it making it instantly recognizable.
At the same time installing the wire harness on the rest of the engine, it's been so long I had to look at some pictures on line to figure out where everything goes.
Bought a brand new A/C pump but that's waiting on more hardware that's still away being re plated.

Going full aftermarket MoTec ecu means doing away with the old Motronic and getting rid of air flap meter, coils. leads and twin distributors leaving a distributor hole in the case to block off. Scrounged around for scrap aluminium but didn't find anything large enough. Being the impatient type I am I did find 2 pieces that when combined would work. More work to make but means I can do it Now and complete another job!
O ringed both pieces when machined to size and even found a stainless arm that was nearly the right shape to serve as a hold down bracket. No load or anything on this so it just needs to hold it in place.
Next will be a block off for the power steering pump but I need to buy material for that. An electric TRW pump mounted in the front will replace it.

That's all on the engine for now until all the materials arrive to build the headers, I already had some but going 3.8L and aftermarket cams, ecu these are now too small but I never really liked the look of them anyway so I'll make new ones.
Next job on the list is the front diff and torque tube, aim is to disassemble, clean, inspect and replace as needed. Dirty oily thing.
Got everything apart and realized I don't have the correct tool to remove the pinion shaft nut so the idea of getting the housing vapour blasted is out the window.
Bearings feel perfect so I didn't feel like creating more work where it's not needed. Started cleaning the housing by hand but that was really slow going, couple hours later and loads of degreaser a good final rinse followed by thoroughly drying and then lubing the pinion bearings to avoid any flash rust starting.

Cleaned up all of the related hardware, needs nothing more than new input and output shaft seals, cover O ring and new drain / fill plug washers.
Put the output shafts in the lathe to polish the surface where the seal will run, easy to do and gives the new seal the best chance of doing its job.







« Last Edit: June 19, 2022, 10:27:02 am by 80 Vert »
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Offline dubstar

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Re: Porsche 964 1990 C4 rebuild
« Reply #118 on: June 19, 2022, 10:40:02 am »
I vaguely remember you saying that you were going 2wd, but definitely keeping it a 4?

Fan looks great, makes the yellow zinc pop more
"I am so clever that sometimes I don't understand a single word of what I am saying."

Offline 80 Vert

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Re: Porsche 964 1990 C4 rebuild
« Reply #119 on: June 19, 2022, 10:52:33 am »
Thanks, yes the original plan was 2wd and back date but these things have increased so much in value I no longer feel the same about cutting it up.
I can't do stock hence modified engine, custom interior and wheels  ;D
2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration