8 cylinder front engine iconic vehicle
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By Daniel5691
#136639
Hello again, dual posting here and RL.
Thanks so much for all the great advice.

Cam towers and heads off. First few photos below...

last photo before disassembly, crank in wrong position and head studs too low. Here we go.
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Drivers side cam tower and a lifter stuck in the housing, (hydraulic valve tappet stuck in bushing according to PET lol)
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I began experimenting with head stud height also.
Does this look correct ?
Thanks.
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By worf
#136670
head stud looks good.

don’t ask me about the 16v head. ‘bin 13 years since I assembled one. @Mrmerlin is the 16v go-to guy.
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By Daniel5691
#136911
Continuing the thread...
Left side driver's side cylinder head images...
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A missing chunk left side driver's side cylinder head.
How to repair? A Time-Sert ? I have been looking also at the aluminum brazing rods from Hobart maybe?
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Hilariously, this passed from me to the machine shop to the "assembling mechanic" and back to me untouched.
I do remember asking the machine shop to address this, but failed to inspect it myself at the time. This one is my fault for not catching initially at the machine shop.
Here's a picture I took of the exact spot at the time of my initial disassembly, years ago...
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By worf
#136929
The machine shop that did the heads… recommended by?

#6 looks like it might have fire ring corrosion at 9 o-clock.

‘tis a lot of pitting also.

Busted boss is cam tower bolt hole?

My guy would probably weld and rethread.
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By Daniel5691
#137354
Yes sir, a cam tower bolt hole.

More photos of the auto-psy...
Driver's side right side block..
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Check out this blob of gray colored goo on the cam tower...
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Full of JB Weld.
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And here's another stuck lifter and sleeve but this time on the passenger side right side
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The parts list is adding up, but I am thankful for all the expert advice.
I am also so happy to be findings these things prior to dropping this poor old engine back in my 928.
I honestly would have just "trusted" the guy who put this back together, then the inevitable would have happened, and then I would have probably never figured out what actually happened.
Thanks x 1000 for your time and input.
i would not be doing any of this without OR and the old birds still stuck in the RL birdcage ha ha
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By worf
#137362
A bunch of JB Weld.

You'll need to find a good machine shop to weld those.

I've no guidance on the lifter sleeves.
Daniel5691 wrote: Wed Mar 02, 2022 2:54 pm Check out this blob of gray colored goo on the cam tower...
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By worf
#137363
Were those cam tower bolt holes upgephucked when you got the motor? Before all the machine shop shenanigans?

I have to wonder if the "assembler" was using an air wrench for those cam tower bolts and that's how they got busted?

IIRC those cam tower bolts ... wait screw IIRC ... they get torqued to 20 N-m according to spec book. That's not much for an M8 bolt. You CAN torque an M8 bolt to way beyond that even in an aluminum hole. At least with a well-supported hole.

But, I'll bet that when you do that to those "exposed" cast holes that the outside crumbles away just like in your picture.

I betcha that's what happened.

Also now gotta wonder if an air wrench was used for everything rather than a torque wrench, the spec book, and proper torquing order.

Assume every single fastener that was touched is incorrect. And I'd probably want to double check the deck surfaces for distortion now too.
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By worf
#137364
Oh. Never mind. I just checked upthread. They were messed up to start.
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By Daniel5691
#137375
worf wrote: Wed Mar 02, 2022 4:04 pm Oh. Never mind. I just checked upthread. They were messed up to start.
Yes sir, both cam tower bolt holes went to the shop originally and initially with damage and in need of proper attention

Education is... expensive.
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By worf
#137612
I warned you that what little knowledge of 16v heads I had is 13 years old.

If we assume that the bushings are not supposed to move in the head, then they are an interference/press fit.

One can further assume that they would suffer from failure modes similar to races in roller bearings:

They get hot because of friction in excess of design parameters. Then they cool. Then they get hot. Then they cool. Lather rinse repeat. The cycles of excess expansion and contraction cause greatly accelerated wear on all involved surfaces. Eventually they get loose, friction gets worse, etc.

In this application why would the bushing be subjected to excess friction from the lifter? Some things that come to mind:
- manufacturing variances just combined destructively
- oil starvation of that lifter, perhaps due to debris

How are all other other bushings?
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By Daniel5691
#140176
An update. All the other bushings are fine. I ended up finding two brand-new sleeves from one of our brilliant vendors, they are on backorder but eventually on the way.
I also heard from Stan "MrMerlin" and he recommended a great machine shop that just KILLED a couple of 32V heads for him that needed welding. I need a set of valve seals (ordered from Roger) and the heads will be on the way for definitive repair.
Good times. :beerchug:
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By worf
#140219
Daniel5691 wrote: Wed Mar 16, 2022 11:07 pm … Stan "MrMerlin" and he recommended a great machine shop that just KILLED a couple of 32V heads for him that needed welding…
So… not a great machine shop then and @Mrmerlin has to find replacements?
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By Daniel5691
#140230
worf wrote: Thu Mar 17, 2022 11:15 am
Daniel5691 wrote: Wed Mar 16, 2022 11:07 pm … Stan "MrMerlin" and he recommended a great machine shop that just KILLED a couple of 32V heads for him that needed welding…
So… not a great machine shop then and @Mrmerlin has to find replacements?
Oh no, I was trying to sound like a young cool person there with that lingo.
My 30 year old son says when he does something really well "He killed it".

The impression that I got from Stan was that he was extremely happy with the work, sorry for the confusion.
the shop is Lorenzo's Fast Flow Cylinder Heads up in Langhorne PA.

I need to figure out the best shipping and how much to insure these lumps.
Again sorry for the confusion. That's how wars get started Ha ha
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By worf
#140294
LoL.

k.
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