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Lotus Europa Forums => Garage => Topic started by: thehackmechanic on Monday,March 02, 2020, 09:56:32 AM

Title: Stuck Valve Shim
Post by: thehackmechanic on Monday,March 02, 2020, 09:56:32 AM
I'm doing my first valve adjustment on my twin-cam after its rebuild 700 miles ago. I got the cams and tappets out without incident, but the shim for #1 exhaust valve is stuck in the spring retaining cup. I've tried a pretty powerful rare earth magnet, and it won't budge. I can't find any posts on this on any of the Lotus sites, but I see posts in the motorcycle world about putting a right-sized socket on the spring retainer and pressing down on it or rapping it gently with a rubber mallet. Can I do that here?

--Rob Siegel
Title: Re: Stuck Valve Shim
Post by: jbcollier on Monday,March 02, 2020, 11:17:19 AM
If the engine is at TDC, and both cams are out, then you can do that with cylinders 2 & 3.  Not with cylinders 1 & 4 though as the valve may hit the piston.

No chance of using a small screwdriver or pick and working it out at the side of the shim?
Title: Re: Stuck Valve Shim
Post by: thehackmechanic on Monday,March 02, 2020, 11:43:20 AM
Boy, there's not much there to pry.

I've ordered a stronger magnet. Think I'll try that before anything more extreme.
Title: Re: Stuck Valve Shim
Post by: thehackmechanic on Monday,March 02, 2020, 12:29:59 PM
SOLVED by Rohan over on the Elan forum:

"Never seen it happen before, normally they lift out with the follower stuck to it by a film of oil. The shim should only be supported at the centre on the valve stem I would try tapping the shim down gently with a punch on one side and the other side should come up so you can then pry it out"

Worked perfectly.
Title: Re: Stuck Valve Shim
Post by: BDA on Monday,March 02, 2020, 12:49:08 PM
Yippee! Glad you got it out!  :beerchug:
Title: Re: Stuck Valve Shim
Post by: jbcollier on Monday,March 02, 2020, 02:08:55 PM
Congrats on getting the shim out.

Ok, a little on the paranoid side I'll admit, but, it's not a good idea to use magnets to remove engine parts unless you absolutely have to.  Using a magnet, magnetizes the part.  Not a lot, true, but some.  This then leads to the part attracting metal filings that would normal drain away.  Again, mildly paranoid, but still good practice.