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Rubber Bungs????????

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Wrigers
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Rubber Bungs????????

#1 PostAuthor: Wrigers » Sat Dec 16, 2017 7:05 pm

Cracking on with A4 engine build, and am in the process of replacing the 8 rubber cushions underneath the block. They describe them as cushions but what do they do??, they just sit flush so to me take its are not much of a cushion.
Also I'm replacing the 4 large o rings at the foot of the bores, it is the best to push them in the grooves prior to sliding the block down, or leave them slightly proud and let the weight of the block take its course. Any advice would assist.

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z1bman
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Re: Rubber Bungs????????

#2 PostAuthor: z1bman » Sat Dec 16, 2017 7:58 pm

they where supposedly fitted to dampen fin noise but i doubt if you would notice any difference if you left them out

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zed1015
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Re: Rubber Bungs????????

#3 PostAuthor: zed1015 » Sat Dec 16, 2017 9:17 pm

The 8 "cushions" in the base of the block do nothing to help dampen fin vibration or cushion anything..
To reduce fin ringing they would need to be inserted between the fins.
These ones are only plugs which serve to prevent muck building up in the holes which could drop in to the crankcase when lifting the barrels as they are close to the mouth of the cylinders.
The holes were originally used to locate the blocks on a fixture at the factory for machining operations.
From a mechanical point of view you can leave them out, leave them as is or bung the holes with something else if you can't source new ones.
As for the liner 'O' rings I always seat them in the grooves.

Wrigers
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Location: Oldham

Re: Rubber Bungs????????

#4 PostAuthor: Wrigers » Sat Dec 16, 2017 10:12 pm

Cheers for that zed1015, i could have saved myself some money if id have known. Ah well you live and learn!!


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