"Barn find" 1986 911 turbo

[fourblades]

Nice crank holding jig! Your engine is looking good.

It should run super smooth with all your attention to measurements and details.

John

[reclino]

Ok I have carved out time this weekend to work on the engine. Plan is to check backlash on the intermediate shaft gears and then I read this step. This seems related to my previous question about alignment between the oil pump shaft and intermediate shaft.
There are no explanation on how to measure this "runout" but the adjustment is "Keep changing spline connection on parts until smooth running is reached"



Does anyone do this step and have a better explanation or pictures/video?

Thanks
David
Performance EngiNerding

[TurboKraft]

David — in 100+ engines we have never found a runout problem, more like binding: the drive shaft should have a small amount of play axialy, able to make a millimeter or two back and forth on the splines. I can only think of one or two instances where there was any resistance, and re-cleaning the splines and re-indexing the the drive shaft resolved it.

[reclino]

Got it, I have good axial float on the drive shaft, splines are all spotless clean and I was planning to wipe a bit of redline assembly lube on splines at assembly.

[reclino]

Backlash checks out good, bottom of the spec, but that's the way it ran for the first 68,000 miles. Would have been easier without the rods installed but got that checked off



Discovered that I don't have an O-ring for the #8 bearing so now waiting on parts to ship. I thought it was in the gasket kit but nope..... That kit really has let me down a few times now.
David
Performance EngiNerding

[reclino]

So the Porsche alternator is a Paris-Rhone unit, configured with internal voltage regulator, powered off of a "diode-trio". Brushes are wired in the N configuration. Most common failure is the voltage regulator. To get to the voltage regulator the alternator has to come out, but is behind the cooling fan and shroud, absolute pain with no space to work and lots of little fasteners to drop and lose forever. My car was sidelined by a failed voltage regulator......
What to do while waiting for that damn O-ring to ship.
After the second pot of coffee the simple solution finally came to me, with slightly modification to the old voltage regulator and brush pack, I was able to rewire the brushes to the P configuration. This means one brush gets power from the field tab on the voltage regulator, the other brush is wired to ground. So just one extra wire has to come out of the back of the alternator, the Field wire. Now just wire it up like a Ford external regulator alternator.

[reclino]

Look another rabbit hole to go down, the car needs to start as well as charge, so the simple thing to do is buy a rebuilt starter, and then complain that it's crap when it fails in a few months. Let's rebuild the original.
The 930 drive Bendix is the same as a 1974 VW beetle auto stick. .

Source NOS Bendix from eBay


Bosch date code 441 January 1984


Tear it all down


Notice paint line part way up nose, starter was dipped in primer then paint after assembly, that's going to be a challenge to replicate.


Stripped, cleaned, dry fit and warmed gently in the oven to drive out moisture.


Out of greenish zinc chromate primer so I used grey.... Sprayed carb cleaner to clean paint off nose, sort of looks like the dip line originally there...


Get distracted while paint dries and tear down original Bendix sprag clutch. Clean relube and assemble.


Clean contacts in the solenoid cap.


Notice blob of solder on solenoid wire shorting it to housing, I noticed this before assembly and corrected it.


Used a small Dremel sanding disk backed up by a cutting wheel chucked in the drill press to resurface the contacts. Easy once I figured out this was the way to do it.

[reclino]

All the oilite bearings were vacuum infused with 0-20 synthetic oil.



Now assembled with fresh satin black paint.

[reclino]

Still waiting on the #8 bearing O-ring to deliver, it's on the truck somewhere in New Bern, but not here yet ..
So trying to use my time productively.
When getting my hardware cadmium plated, they lost one of the clips for the air filter "barn door".
Its not listed in the PET, but the dealer assured me the clip called out for the 3.2L airbox was the same PN for the 930. So I ordered one some time back.
Assemble the airbox with fresh paint and fit up the original gold cadmium clip, and the new Olive Zinc plated one.
Old one snaps tight, new doesn't even begin to pull the door tight. So got out the water pump pliers and tweaked it a bit, still barely holds and isn't fitting at all like the original.
I can handle them not matching for color, but the damn thing doesn't even work right.
Old clip, with fresh cadmium.


New clip. Floppy and sad.

I have bent it enough so it's doing a half ass job, afraid if I bend it to much it's going to kink, the angle of the latch to the body isn't something feel like i can adjust with just hand tools .

[reclino]

I got a lot of pictures of it all happening, but these 2 sum it up just fine.




Never torqued that many anything, that fast, ever.
David

[356911930]

Nice work. I hope to eventually get there with my engine…

Rahl

[fourblades]

Congratulations, that is a big milestone!

You are doing such a thorough job on this rebuild...just amazing.

Things should move faster now?

John

[reclino]

Yes, should go smoother now that the big scary part is done. I have no expectations of timeline, and am enjoying each small step. Yesterday I realized I didn't have a clutch alignment tool, and none of the local parts stores even list the correct one.
Well it's just a simple precision machined step pin with 3 important dimensions.





So very nice 🙂

[reclino]

The factory manual calls out special tool 9236 to counter hold crank pulley when tightening to 80 Nm




Does anyone actually use this tool. Seems like the crank could just be locked at the flywheel and torqued at the other end.
I could make a tool for this but seems like overkill.

David

[reclino]

Knock sensor for J&S ignition needs to mount somewhere. Yes I know Porsche used 2 sensors on "bridge" bolted to heads or cylinders, and I could have modified my heads to accept this bridge. I didn't want to modify the heads, only bolt on changes for this build.
I am going to start with one sensor on the block. Under the throttle bell crank bracket seems like it could work. Would need to cut down the leg to mount it.







I would prefer having a spare piece to cut down, does anyone have a spare 911 110 091 07 bracket? Looks like I need to trim 21.92mm off of the long leg, this allows for a ground flat washer under the knock sensor so it has a good mating surface to the case.
Actual casting number on mine is 930.110.360.02

[reclino]

Let's take a step backwards and remove the pilot bearing and flywheel I had test fit. A fun challenge for this Saturday is how am I going to torque the 2 obstructed case nuts behind the flywheel??? One of them I could. Get a socket on, 2 are just to tight,.so I did torque to feel with a 13mm box wrench.
I can do better.





If your torque adapter is at 90 deg to your torque wrench, there is no change to indicated value.
I thought about welding a socket to the wrench,.or buying one of the adapters that clamps to your box wench.

[reclino]

The digital torque adapter is 1/2" output, I fit a 1/2" box wrench to the 13mm nuts and torque adapter fits into the open box wrench nicely.
Yeah it's floppy, but I am at 90 deg to the fastener, so the indicated value is correct.
Is it perfect? Nope but it's more accurate than just guessing

[reclino]

Installed and torqued items yesterday.
Flywheel
Pilot bearing
Crank pulley
Crankcase thermostat
Oil feed adapter for turbo, including ball bearing and low pressure switch
Oil pressure regulator
Oil overpressure relief valve

Unable to install timing chain guides as the gasket kit was missing these crush washers.
Ordered a bunch of crush washes and assorted bits and bobs.

[930cabman]

Originally Posted by reclino

The digital torque adapter is 1/2" output, I fit a 1/2" box wrench to the 13mm nuts and torque adapter fits into the open box wrench nicely.
Yeah it's floppy, but I am at 90 deg to the fastener, so the indicated value is correct.
Is it perfect? Nope but it's more accurate than just guessing

I probably wouldn't be too concerned with having the exact torque at this location, sure is has importance, but not for a rotating component. Great progress btw

[TMo]

Nice work on this project. It seems a lot of times barn finds just end up in someone else's barn.