mit Wasser

Geza,

I am speculating that you have worked in Aerospace or Formula 1? Wherein all the bolt heads have been drilled at every shoulder for infinite (360° degree orientations) of safety wire.

You are technically correct with your wire pull orientations.

The harsh reality in my workshop is that I am not going to drill each bolt head six times. In mistakeprooffing game not unlike Wheel of Fortune-the one safety wire hole lands where in lands after torquing. And that is where your wiring task begins. If one gets loose and rotates 123° before the tugging begins, I am ok with that.

Thanks for the effort on the wire pull diagram -it's caused me to reflect that I should have started my wiring in the clock-wise orientation to minimize the above effect.

worf928

As far has head gaskets are concerned, IMO, if you've got a complete maintenance history on coolant changes and know how the 928 was used it is possible to make a reasonably-informed decision on the likely health of the aluminum surfaces on either side of the head gaskets.

I've encountered two 'head gasket' cases. One an S4 and one a 16v. In both cases it was due to a factory defect in the head gasket that cause leakage. I have seen, proportionally, a bunch of 32v heads with coolant corrosion damage close-enough to the fire ring to require rework.

I'm glad to know that there are some experienced 928 folks kibitzing at close range. This is clearly a show-and-tell thread and all of the decisions have been made. I will not ask 'why' questions, but instead 'what' questions.

worf928

I'm highly interested in the prep for engine bay painting. At least with the later cars there seems to be a coating on top of the paint (which is on top of the thick undercoating) which looks like cosmoline but doesn't 'cleanup' like cosmoline so I assume it isn't. Was this the case with this car or Minerva? What was done to prep the bay for paint? Coating degreased, scuffed, etc? Or coating (paint, undercoating) stripped to paint (or paint to undercoating or to bare metal?)

docmirror

Move the tension draw position to the spoke at 2 O'clock, from 9 O'clock in the picture. Improperly configured safety wire may actually cause the nut to come loose.

Otherwise, outstanding work. Difficult to find fault, as you are doing it all the right way.

Mrmerlin

looks like a great project ,lots of cash being spent.. important parts getting refreshed.

That said.... the 16 V engines have the worst HGs in terms of longevity.
Every 16V that I have taken the heads off of has had poor condition head gaskets.
Most are leaking along the top edge of the gasket into the valley, white crusty deposits.

Frankly I would pull the heads and swap in the new HGs now,
in 3 years it will be an engine thats had new HGs, and wont be an issue for whomever is driving the car,
and will be worth more than an engine with original gaskets thats got leaks along the top edge .
For the smart mechanic , the hard work is already done the engine is ready for your fingers to get busy.
Please reconsider this, Greg Brown will tell you the same thing.

mit Wasser

The engine bay, inner fender wells, radiator support was stripped of all items. We then tried a lot detergent based cleaners. The best seemed to be scalding hot water with dish soap (or simple green) using a grey 3M scrubbing pad hand scrubbing all the corners, rinsing & reinspecting going after any missed spots. The earlier photo in the thread shows William doing the DI rinse. Air dry for 24 hours, then another 3M final scrubbing. Airblast, wipe down, then a light (very light) coating on any exposed metal surface with UPOL etching primer. (Wear a mask, very toxic to inhale) Air dry 24 hours. Final wipedown & airblast. Color matched silver base coat in a small bottom feed detail spray gun at 35 psi. Air dry 10 min. The a single coat of matte clear coat. This was done over only the the areas that had the factory silver in the engine compartment and wheel wells. Airdry 24 hours before fondling.

GregBBRD

For everyone else, reading along, (who hasn't already made a decision to not pull their heads after 40 years.)

Exactly how long does anyone think those paper gaskets, inside the engine, soaking in acidic coolant are going to last?

I've found that the lower the mileage, the longer the coolant sat in the engine, getting acidic and eating at the gasket, heads, and cylinders the worse the problem gets. And the longer the acid coolant sits without getting hot, the worse the damage seems to be. Last time I needed an "early" engine, I took four of Mark Anderson's used core engines apart (they do not drain the old coolant from their engines they remove), before I found an engine that was rebuildable....the first three had the top of the cylinders completely "eaten" away from the coolant. One actually had "aliens" growing inside the water passages.

I've taken a couple of low mileage engines apart (less than 20,000 miles), where the block and heads are complete junk....a real shame is someone cares about a "matching number" car.

In contrast, higher mileage engines (like William's car) got serviced at more frequent intervals and (generally) do not suffer from such severe damage. (These higher mileage engines got water pumps, hoses, etc. and had the coolant changed more often.)


I suspect that this car is destined to be a "show queen" and will not get driven much, so I "kinda" understand the "gamble". It will be interesting, for a show car, to see how the heads, the cam carriers, and the related hardware is going to be made "pretty", without removing all the pieces to plate and clean.


My suggestion to all that find themselves at this "conundrum"...and you are only a couple of hours away from having the heads off the engine. Do the job once, do it correctly, and forget about it, for the next 40 years. (Same question....how long do you think 40 year old paper, sitting in acidic coolant, is going to last?)

GregBBRD

Yes, he will. But what does Greg know?
I've "stuck" my nose into this project once, with some suggestions about hoses, belts, and some other pieces. (He was buying some non-factory belts, hoses, and other "visible" pieces, which I would consider inappropriate for a "show queen".....and suggested he was making a mistake.)

I was met with "I've got stuff to do....can you leave me alone?" (Exact fricking quote.)

Pretty hard to do anything but walk away, right? "Sorry to try and help", was all I could think, as I did exactly that.

Heh, He's a good buddy of William's and William used me for absolutely nothing on his car....hard to not know there's some sort of issue there! He's also a good buddy of Mark's....and Mark blames me for him putting low octane fuel in two of his engines....we don't even talk anymore. So, none of this is a complete shock.

Lines have been drawn.

I get it. I can't possibly do everything 928 for everyone.....I don't even want to try.

No big deal. I've got more than plenty of stuff to do, every single day.

docmirror

I have welded air-cooled VW heads, and Ford Alum heads, Honda MC heads. Are the 928 heads weldable? It would seem that a good welder should be able to recover otherwise distressed heads with proper conditioning and cleaning.

polecat702

The Alusil, is hard to weld, and should be welded in a purge box with helium as a backing gas, and a through cleaning before attempting. I seen plenty of porosity, cratering, and surface cracks from **** poor preparation. It's gotta be clean, and preheated.

Rob Edwards

Of course, the only way to truly know the condition of the head gaskets would be to pull the towers and the heads. But if the condition of the water passages elsewhere in the block are any indication (and they may not be), this motor was very well maintained. All that said, William and I made the full-court press admonition to pull the motor, and Paul was polite but firm about mission creep and sticking to his plan. Totally respect that, his car, his project, and he's a big boy if a head gasket goes kaphlooey.

Sure.

docmirror

Are the heads Alusil? Oh - I covered the cleaning and prep. I'm no NASA welder, but I can lay a decent bead. If we have a pro with the right equip at one of the eaten up heads, what's to lose?

polecat702

Ya got nothing to loose, everything to gain after it's done right and re-machined. Back when Carbon Tet, was available, Tide, lots of hot soapy water, got the crud off and out. Then preheated and scrubbed with Carbon Tet, and start welding. Slow and steady was the way. I never liked Argon, on Aluminum, you'd get carbon oxidation on the weld as it cooled always preferred helium in the box.

worf928

Yup. 928 heads are weldable.

I don't doubt what you write above. One thing though, the 928 heads are not Alusil. They're 'just' aluminum. Nevertheless doing extensive corrosion repair to the heads is not a 'Junior-level' job. The heads expand, valve guides drop out and, depending upon how extensive the welding, warping will happen which will need to be corrected. It can be done. Even swiss cheese heads can be resurrected. At a price. In the end it's the number of hours of skilled labor required to make them right.

GregBBRD

We preheat them and weld them up on a regular basis. We also just welded up a big pit on the top of a cylinder, without hurting/distorting the bore. (An acid eaten pit big enough that it would have rendered the block junk.) Surfaced the top deck of the block and was done. (Surfaced both sides to keep the compression the same on both sides of the engine.)