Kevin in Atlanta

Looks like the allen bolts backed out?

auzivision

The unidentified object turned out to be part of the "Y" shaped bracket that the rotor attaches to. I presume it was broken and must of dropped after he removed the 3 screws holding the rotor on.

Amazingly, the Cam gear was still fairly secured to the cam via the M17 bolt, but it didn't take much to break free (like less than 40 Ft-LBs). My theory know is the cam bolt wasn't torqued to spec, the cam gear has been rattling back and forth against the shaft key. This eventual led to the cam tip failing and rotor bracket failure.

The way the cam tip broke and how well the broken pieces fit back together makes me think, luckily, the gear did not spin relative to the cam... so the valves should be okay.

Notice the strange discoloration, like oil or exhaust fumes, emanating like brown spokes on the back of the gear. I suppose a little oil seeping out may cause this. Just looked peculiar and the silhouette shows that maybe is was secure... ruling out my theory.

Bottom line both the bracket and the cam failed right at the joint key. I'm guessing this is the root of the original problem... which IIRC was a timing belt light and unusual noise. Engine/ignition was shut off and car towed to home.

So perhaps this is just a cam job, which is easier than a valve job. If so, isn't it possible to swap without pulling the engine?

Brett Jenkins

Phil, I have the camshafts out of my 88 that you can have, if they work and if Hans doesn't mind. I offered them to him last week. I might still have the cam gears and associated parts, etc, too. I will take a look. I am coming up this weekend, probably early Sunday. I was boxing up everything I have left and bringing them up to Hans.

auzivision

[QUOTE=Brett Jenkins;10081769I am coming up this weekend, probably early Sunday. [/QUOTE]

I was wondering if you still had those cams. I think it's cool to see you car live on in so many other Hoosier vehicles


How long will you be in town? Open for a beer on Monday by any chance?

Brett Jenkins

Yeah, I think I might be able to work that in. I will let you and Hans know.

hans14914

I have a pile of cams, so at least that part is not an issue.

Checking to see if the valves have kissed the pistons is the next step. I advised Phil to get a borescope and check to see if the carbon on the crowns has been disturbed: shiny crescents=motor pull.

Leon Speed

That's not good :-(

But you can get a set of Colins cams now :-)

Mrmerlin

this failure could have been caused by three different things

Improperly torqued cam pulley bolt and or loose rotor securing screws causing the spider the crack, and the cam bolt to work loose

Overtightened timing belt, thus making the load on the DS cam snout enough to fracture the cam, also could have been caused with a failure of the WP bearing seizing thus increasing the loading on the belt

A loose oil antibackflow valve seat, causing the cams to start seizing in the cam journals,
take the plug and ball and spring out of the head and inspect the seat if its loose then you need to remove it clean out the area glue it back in with Green loctite and stake it in place

Want to be

First step, looking for a borescope

I can't say enough of how much support and generosity towards my problems. I can only hope, the car will be back alive again someday.

thanks you "polecat702 & Brett" for the parts being supplied.

More to come, i am listening to everyone.

Want to be

Today, i could not locate a bores scope, unless i would purchase one.

For now, i decided to prepare for the valve cover to be removed. Either way, i will need to remove it.

Before doing so, i thought it would be a great time to remove the old and deteriorating heat shield on the hood. I put a tarp down and began scraping away, an vacuuming.

Next removed the accelerator, PB blasted the valve cover bolts, removed the air box, remove the gas tower shield and taped of connections so no debris would enter the vacuum hoses. Boy, the one hour went FAST.

Quick question, the last photo displays a plastic connection. I had noticed it was fractured. I purchased new one, but was wondering if anyone had a write up on the connection piece. Does the logical order matter on each post, i would assume so, but needed to ask the dumb question.

G8RB8

The "14 pin connector"
https://rennlist.com/forums/928-foru...nder-hood.html

Mrmerlin

#1 Roger sells the whole connector housing and pins and sockets

jeff spahn

It's easy to rebuild that with the parts from Roger. did mine two years ago

auzivision

Phil, please watch these video to get a good idea of what will be entailed in the cam swap, TB, timing, etc.








This one also contains a lot of good information:

Want to be

This is awesome, i have yet been able to watch the entire video but will very soon. Looks dated but who cares its perfect. I have removed the Cam cover and covered it up with an old shirt.

The exhaust CAM shaft part number is 0977 & 9281054914 a5 9 ( couple numbers at end might be wrong )

Will post pictures soon. One question, do i need to remove both CAM shafts or can i just remove the one that is broken.

Video is just awesome. I had watched a video last night on a Cadillac engine and BMW. I could not find a 928 video.

Also , thanks for the write up on the 14 pin connector. Its perfect. Need a nice video...LOL