"Barn find" 1986 911 turbo

[Mixed76]

Learn something new every day. I know the silver anti sieze is nickel not silver, I guess the concern is it somehow migrates out of the threads?

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[fourblades]

Wow, the silver plating sounds good...

Not having to battle exhaust studs ever again would be nice.

[reclino]

Haven't updated the thread in a while, engine is slowly coming together.





Got side tracked with the throttle body, it's all to bits now, waiting on me to develop a rebuild kit for it.


Rear engine tin is warped due to my terrible welding skills.



Been setting up sprocket depth with my shim kit



Drivers side required 2 0.5mm factory shims, and 2 0.3mm Performance EngiNerding shims. It's within 0.07mm of ideal location.....



New cam feed oil line doesn't play well with original tensioner oil feed.



Hours later, it's amazing what I will happily spend time working on.

[reclino]

While discussing my engine and the silver plated exhaust studs with one of the materials engineer's at work, he reminded me that silver and aluminum are highly reactive with respect to galvanic corrosion....... So may be replacing the exhaust studs with titanium, will use the silver plated nuts and washers though ..
Red high temp Loctite would probably mitigate the corrosion, but I feel safer just putting in titanium.

[fourblades]

There is a type of stainless with roughly the same galvanic potential as aluminum. Dr. Evil, the famous 901 transmission rebuilder, included stainless washers and nuts in his rebuild kits. After 10 years of service I don't see any corrosion around them.

No idea if this is helpful information or not. I could dig up the specs on the stainless if you want.

John

[reclino]

Galvanic potential is a complex subject.



https://l-36.com/corrosion.php

I am not an expert on this, but love discussing this with the real experts. My understanding is to any normal person looking at the chart silver to aluminum looks better than titanium to aluminum, however silver oxide is very conductive, but the oxide layer on titanium is less active than the base metal.... Or something to this effect, need to discuss further with the experts. Plating on the fasteners effects how all this interacts, but some characteristics of the base metal remain after plating...
EngiNerding

[reclino]

Let's just say I am really really good at installing and removing the passenger side cam sprocket.
Gave up on trying to hand hold the calipers,








Can remove and install the sprocket without disturbing the straight edge.
Hopefully will get more repeatable numbers this way

[reclino]

Passenger camshaft sprocket installed and torqued measures about .0015" runout with this setup. I now have the passenger side adjusted to within 0.047mm of my measurements of the intermediate shaft on my surface plate.
I am at the limit of my tools at this point.
Going to roll the engine over and check the drivers side again.
Then I can move on to the fun and excitement that is RSR rocker shaft seals .....
EngiNerding

[reclino]

Setup for the drivers side is almost the same, except the base I attached to my calipers eats up a significant amount of depth travel.





I have a very nice 1.0000" standard that came with a Mitutoyo 1-2" micrometer....

The only concern I have is I am making all these measurements referenced off the case, and I know it is mismatched by about .004" from side to side. So I stuffed a feeler gauge under the short side of the case to compensate.....



Unfortunately my "datum extender" ring just added to many moving pieces, and it should have been made just thicker than the case.... I never could get repeatable measurements with it installed.....
Now to see if there is another way I can check these numbers.
EngiNerding

[reclino]

Reading the dial indicator counter clockwise, that's .057" at 0 deg TDC on cylinder 1.

[reclino]

Getting closer and closer.









Managed to extend an indicator down the spark plug hole to check TDC. Easy to adjust my deg wheel it's friction fit so able to clock it 1.5 deg so 0 is actually O....

[reclino]

It is now a long block.
So much work to be done, and even though it has not been a perfectly smooth and orderly build, I feel it's good for a first time builder.
EngiNerding

[reclino]

Test fit the turbo today....

[reclino]

Got a dead pedal, and sourced a roll of ribbed rubber mat, cut out and glued on a little pad.

[reclino]

Throttle rod repair attempt with MAP gas....


Little bit of flux, oxy acetylene, and some careful application. I am no professional but this looks serviceable now, much better than my attempt with MAP gas.

[reclino]

Changing to headers forced a change in the oil lines. The scavenge line under the engine needed to be changed for the early style. I found a NOS factory Porsche line on Ebay, and of course it fit poorly.
Finally got after it today and made some careful adjustments.


Should be parallel to the cooler, and it's just so wrong.



Really depressing to buy new factory parts and the fit is this terrible.

So after trying to hold the line in the bench vice and failing. I figured I would use the 20 ton hydraulic press.



First needed to un-bend this section, used the press a 2*4 and little v-block to hold the tube in position, then lift up on the free end, loose up the press, slide tube in about an inch, clamp it and lift up again, did this about 7 times along the tube so only bending a small amount in each location.



Rotated the tube 90 deg and worked in this plane using the same technique, little bends spaced an inch or so apart.





So they must have had a jig at final assembly at the factory to perform the same job..... Or quality of replacement parts is just ****.
EngiNerding

[TurboKraft]

Originally Posted by reclino

Should be parallel to the cooler, and it's just so wrong.
…
Really depressing to buy new factory parts and the fit is this terrible.
…
So they must have had a jig at final assembly at the factory to perform the same job..... Or quality of replacement parts is just ****.
EngiNerding

If that was a NOS part made 10+ years ago, there would be a fair shot at it fitting right the first time.
At least 3 companies making them now, and 2 fit terribly (hit the case, way crooked), and the 3rd is functional but not perfect.

It isn’t new news: parts aren’t made like they used to be. :-(

[reclino]

Based on the second label stuck on top of the first, this was pulled and shipped 05-09-2000, the tag and tube had similar amount of shelf wear and grime and one of the staples was under the tag with no evidence of ever being replaced, best I can tell it's a genuine Porsche part.



Of course being eBay and an old part anything could have happened to it.
But it fits correctly now.



I test fit the intake manifold today, and am now stripping a few more pieces of engine tin.

[reclino]

Seems like such a simple thing, the O-ring at the base of the distributor.
I saved the original when i tore it down, it's the red one, feels like silicone rubber to me.
The Bosch distributor kit came with a new black one, with the classic high profile peak. I ordered one each aftermarket but the E -eurotrash sent 2 from the same aftermarket supplier (frustrating) I was trying to figure out ALL my options and they screwed me.
My OCD is paralyzed by choices like this.... Will the best part please step forward.





Does anyone know what Porsche is selling these days?? I would doubt that it's the red silicone anymore.
After much thought I put the Bosch "O-ring" on.... Good enough for the next 10 years.
EngiNerding

[reclino]

Yet again I find something new from Porsche a disappointment.
These are the cam oil restrictors, purchased new from the dealer. 901-105-361-03
The undercut area where the thread blends out to the shoulder on the old fitting is cone shaped to center the crush washer. The new fitting has a very different profile, I tried to highlight this with red ink.



The effect is the washer squirts out from under the fitting when you torque it tight.
The new thermal time switch I bought new from Porsche is the same. I had to find a small O-ring that fit inside that crush washer to keep it centered. No pictures of that as it's already installed with blue Loctite.