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Old Oct 8, 2010 | 02:07 PM
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From: Worksop S81
Default forged engine question

do forged engines make more rattle type noises than a normal untouched engine??

cheers
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Old Oct 8, 2010 | 03:09 PM
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not on my p1 no.
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Old Oct 8, 2010 | 03:13 PM
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Piston slap when cold or noisey in general?
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Old Oct 8, 2010 | 03:13 PM
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it is usual to get piston slap on cold start on forged engines....but the noise should go away once the engine is warm.
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Old Oct 8, 2010 | 03:15 PM
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What rajscoob said^^^^^^
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Old Oct 8, 2010 | 03:22 PM
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never had a forged engine so was just checking, car runs,drives fine and not using any oil water ect...
just sounds abit rattly on left side but could also be coming from clutch?? because its more at the back of engine bay.
im the type of person that always notices the smallest of noises then does my head in until i find it
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Old Oct 8, 2010 | 03:23 PM
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Yes as they have to expand more, there will be more slap and rough running when cold.
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Old Oct 8, 2010 | 03:37 PM
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My old 2.5 build used to sound like a taxi on startup, with forged pistons, and were still slightly rattly even when warm.

The new Cosworth short block rattles for about a second, on startup (possibly until the oil has had time to be pushed around), then it goes away.

Maybe it's more a question of whether the block has been honed properly to accept the pistons ?
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Old Oct 8, 2010 | 03:41 PM
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well im glad nobody said its fu@&ed
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Old Oct 8, 2010 | 03:43 PM
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It does depend though mate, before my forged piston actually LET GO, it slapped to hell, now I've rebuilt it with the same pistons but bigger obviously for the rebore.... it doesn't do it 'much' still sounds rough as hell cold, but nowhere near as bad as before.

Just goes to show, det , bad timing can and WILL destroy ANYTHING.
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Old Oct 8, 2010 | 03:44 PM
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i think so mate. my new forged 2.1 stroker rattles on start up....and sounds like a diesel when warm.
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Old Oct 8, 2010 | 04:00 PM
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depends what heads you got on as well, sti V4s have shims and they do make a little more noise than hydrauls.
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Old Oct 8, 2010 | 04:10 PM
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Originally Posted by 2.5STI
i think so mate. my new forged 2.1 stroker rattles on start up....and sounds like a diesel when warm.
your engine rattles on start up and sounds like a diesel even when warm.think i would be trailering it back to whoever built it if its that bad.
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Old Oct 9, 2010 | 11:17 AM
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My forged 2.1 does make a rattling noise when its cold or hot.

I have been told its normal tho with the engine build i have.
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Old Oct 9, 2010 | 01:02 PM
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my 2.1 makes more noise than standard. have been told it is down to the pistons. just the make that was used is abit louder than other makes.
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