Author Topic: Cam Journal Cap Replacement  (Read 2300 times)

Offline joshb

  • Motobrick Curious
  • Posts: 10
Cam Journal Cap Replacement
« on: September 28, 2020, 12:02:22 AM »
Hey y'all.

I fear that I may have goofed.

On my first go-around of adjusting the valves on my K75 I over-torqued the valve cover shoulder bolts, and ended up sticking in a few helicoils to right my wrong. As of 2-3 months ago I developed a small oil leak around the valve cover, got mad at it, and decided that I'd buy some new cam journal caps to 'start from scratch'. I located a set on eBay, installed them, and went out for a test ride. Everything seemed great until I noticed that my left leg was quite wet, and quite hot, because it was covered oil.

Long story short, the 3 of the cam journal cap studs had shorn off. I'm in the process of replacing the stems, and hoping that I just failed to torque them down properly (I gave them 10 nm). My question is, am I on a fool's errand trying to replace these? Should I stick with the original journal caps and their heli-coils instead? Is there any information on what that cam journal caps should be torqued to?

Shame:

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This one is proving to be fun:

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Whelp:

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  • Oakland, CA
  • 92 K75S

Offline John Lang

  • ^ Proficient Motobricker
  • Posts: 209
  • John Lang
Re: Cam Journal Cap Replacement
« Reply #1 on: September 28, 2020, 06:40:49 AM »
Cam journals are probably bored in-line. You might have to replace the engine block. I hope I'm wrong.


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  • Ottawa, ON Canada
  • 1987 K75C

Offline Laitch

  • Faster than a speeding pullet
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Re: Cam Journal Cap Replacement
« Reply #2 on: September 28, 2020, 07:25:18 AM »
My question is, am I on a fool's errand trying to replace these?  Is there any information on what that cam journal caps should be torqued to?]
What were you using for guidance in this procedure? There's information in BMW's K75/K100 2V workshop manual here. There is a specific tightening technique you might have overlooked that prevents stress on the blocks. Caps are not interchangeable. I'd probably use the original caps in their original positions. Inspect the bearings for damage.

. As of 2-3 months ago I developed a small oil leak around the valve cover, got mad at it, and decided that I'd buy some new cam journal caps to 'start from scratch'.
You might have overreached. The mating surfaces of the cylinder head and camshaft cover must be absolutely clean of oil and the correct amount of appropriate sealant must be applied; otherwise, oil leaks are a certainty.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline The Mighty Gryphon

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Re: Cam Journal Cap Replacement
« Reply #3 on: September 28, 2020, 07:27:14 AM »
Cam journals are probably bored in-line. You might have to replace the engine block. I hope I'm wrong.

You would only need to replace the cylinder head.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

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