Author Topic: Barrel shim  (Read 167 times)

Fowler

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Barrel shim
« on: March 04, 2020, 10:20:44 PM »
Hi all,
   I pulled the barrel of my 8/1 today and found a shim between it and the block, there was a gasket either side of it. Is the shim there to adjust the compression ratio? Probably a stupid question but its the first CS ive stripped.
Cheers
    Steve

sirpedrosa

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Re: Barrel shim - Wellcome to LEF
« Reply #1 on: March 04, 2020, 10:42:31 PM »
Hi Steve

Absolutely right! Shim and gasket are in order to set the bump clearance - distance between piston crown and head.

Any help needed, just whistle.

Cheers
VP
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227

Fowler

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Re: Barrel shim
« Reply #2 on: March 05, 2020, 09:26:18 AM »
Thanks VP, much appreciated. Mny idea what the distance should be between the crown and head? How does the gasket compressability factor into this?
Cheers
    Steve

sirpedrosa

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Re: Barrel shim - more info
« Reply #3 on: March 17, 2020, 07:54:20 PM »
Hi Steve

My apologies to not answer earlier but I missed your post.

Distance between the crown and head is measured global, Take a close look to my thread, here: https://listerengine.com/smf/index.php?topic=8320.msg102498#msg102498

First you fit cylinder and be sure piston is not above face of cylinder. Put head gasket, soldering wire, and head on top.

Torque all down to spec. widthrow head and measure tin with calliper. Adjust bottom cylinder shims, remove if too high, add if to low (the head!).

Any questions...

Cheers
VP

« Last Edit: March 31, 2020, 05:29:52 PM by sirpedrosa »
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227