Lotus Elan

Timing chain touching front of inside of case

PostPost by: vxah » Mon Feb 25, 2019 8:37 am

I had the same problem when I rebuilt my twink, I could see that it had been like it before rebuild because the wear mark on the rubber damping guide was at an angle even though the guide was installed inline with the block face. I looked at all things and concluded that the cylinder head may have been machined incorrectly having the thrust grooves that locate the cams 0.100" too far back? In the end I spaced out the cam sprockets to align everything, it's been fine so far!
Looking from the crank sprocket up towards the cams you could see the misalignment airc, I have some pictures if you are interested?
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PostPost by: thehackmechanic » Mon Feb 25, 2019 8:58 pm

Just to close this out, to quote an old Jackson Browne song, "what I was seeing what wasn't what was happening at all." There was never actually timing-chain-to-metal-case contact. The chain was rubbing against the squeezed-out cork gasket and the small amount of RTV on the edge. I took a flat file and smoothed it off. Voila! Clearance! There would certainly be more clearance if the gasket and backplate and chain were all a smidge thinner, but I think I'm good.

Thanks so much, everyone, for your input.


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PostPost by: englishmaninwales » Mon Feb 25, 2019 11:31 pm

I had a similar problem with the Burton supplied front cover for their pump module. It required metal removing around the coolant passage due to malposition of the casting core.
Very frustrating, especially with Burton?s response.
However, the pump module / timing covers once installed correctly work well.
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