Piston Slap?
Thread Starter
Joined: Mar 2003
Posts: 266
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From: Brooklyn Park, MN
Piston Slap?
okay after i got done putting in my forged piston and rods i notice as i was turning the crank i can hear a little sound like click. is that normal. i hear that forged piston run a bigger piston to wall clearances because they expand more than cast piston. i have wiseco piston 75.50mm over bore the block my .020. i was wonder if that is normal. my motor is a d16z6.
Click here and listen....... a video of piston noise..
Piston
http://www.we-todd-did-racing....5NTQx
i was reading up on this
Piston Slap
Piston rattle or slap when an engine is cold indicates too much clearance between pistons and cylinders. This may be due to excessive assembly tolerances or worn cylinders. Some forged pistons have a higher rate of thermal expansion than cast pistons, and may require slightly greater cold clearances to compensate. This, in turn, may produce some unwanted piston noise when a cold engine is first started, but it has no effect on piston performance, durability or longevity.
Click here and listen....... a video of piston noise..
Piston
http://www.we-todd-did-racing....5NTQx
i was reading up on this
Piston Slap
Piston rattle or slap when an engine is cold indicates too much clearance between pistons and cylinders. This may be due to excessive assembly tolerances or worn cylinders. Some forged pistons have a higher rate of thermal expansion than cast pistons, and may require slightly greater cold clearances to compensate. This, in turn, may produce some unwanted piston noise when a cold engine is first started, but it has no effect on piston performance, durability or longevity.
Will you make something up for me please?
Joined: Sep 2001
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From: SoCal
Re: Piston Slap? (VtecbOi)
Wiseco pistons are known for their high silicone content (even more than JG ones, I've heard). It should allow for tighter tolerances and quieter running when at normal operating temperatures. High silicone pistons have a low expansion rate. Your situation should be normal at cold startups.
EDIT: Found this:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">Forged pistons become stable at higher rpms, once their material expands, but can cause noise as they slap around in the cylinder walls at low speed when cold. The aluminum used for forged pistons differs in its proportion of silicone and copper, and thus offer different expansion rates. Additional silicone in a 4032 grade alloy yields a piston with lower heat expansion properties that maintains a tighter piston to wall clearance. Another grade of aluminum, 2618, contains less than one percent silicone with a higher content of copper. The composition of such pistons permit greater expandability and require greater piston-to-wall clearances, making it suited for the extreme heat and pressure caused by high-boost turbos, superchargers and loads of nitrous.
</TD></TR></TABLE>
EDIT: Found this:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">Forged pistons become stable at higher rpms, once their material expands, but can cause noise as they slap around in the cylinder walls at low speed when cold. The aluminum used for forged pistons differs in its proportion of silicone and copper, and thus offer different expansion rates. Additional silicone in a 4032 grade alloy yields a piston with lower heat expansion properties that maintains a tighter piston to wall clearance. Another grade of aluminum, 2618, contains less than one percent silicone with a higher content of copper. The composition of such pistons permit greater expandability and require greater piston-to-wall clearances, making it suited for the extreme heat and pressure caused by high-boost turbos, superchargers and loads of nitrous.
</TD></TR></TABLE>
Thread Starter
Joined: Mar 2003
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From: Brooklyn Park, MN
Re: Piston Slap? (shamoo)
right then how come it's making a noise when i'm turning the crank. the motor is on the engine stand... the head is off. i'm not even done putting it together yet.
Joined: Jan 2004
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From: south the deep south, tx, us
Re: Piston Slap? (VtecbOi)
if it is on the stand it is not warmed up. hence the pistons have not expanded to there operating tolerances. that is why you hear the slap when you turn the crank.
Thread Starter
Joined: Mar 2003
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From: Brooklyn Park, MN
Re: (VTAKKK!!)
thank god... are you sure man.. some other guys at turbod16 said it shouldn't be making any sound... i really don't know.. everything was done at the shop as well as buying the piston.. i just put it together. i did file the rings. i don't know if the rings might cause it.... are you sure.. did you hear that in your motor... i know it's suppose to have a little clearance but i'm not sure if it would still make that sound
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Joined: Aug 2004
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From: Jamestown, oh, united states
he is saying it is the oil clearance so oilc can get upin there not the actual oil itself.
I think it is like everyone on here and turbod16 said and it is piston slapa little because you dont have it warmed up to operating temperatures.
I think it is like everyone on here and turbod16 said and it is piston slapa little because you dont have it warmed up to operating temperatures.
Thread Starter
Joined: Mar 2003
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From: Brooklyn Park, MN
Re: (3lue_by_u)
have you watch the video.... well that mean it's suppose to make a slapping noise right. i wonder how come some people forged doesn't make noise...? does your or does anyone who did piston upgrade have the same problem. did yours?
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From: Chicagoland, usa
Re: (90blackcrx)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90blackcrx »</TD></TR><TR><TD CLASS="quote">Are you sure the sound is coming from the block and not the head ? Is the head on at all ? It almost sounds like the valves are opening and closing letting air in.</TD></TR></TABLE>
He said that its on the stand and the head is off
He said that its on the stand and the head is off
Joined: May 2005
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From: Mechanicsville, MD, US
Re: (splitime)
It sounds to me like something is sealing and then a seal is breaking.
What seal is being broken I have no idea. I'd assume oil on the cylinder walls/rings is causing a seal, and then moving it is breaking the seal.
I don't really know, though.
What seal is being broken I have no idea. I'd assume oil on the cylinder walls/rings is causing a seal, and then moving it is breaking the seal.
I don't really know, though.
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Joined: Nov 2002
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From: Illinois
Re: (splitime)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by splitime »</TD></TR><TR><TD CLASS="quote">
He said that its on the stand and the head is off</TD></TR></TABLE>
But watch the video, the head is clearly on the engine.
He said that its on the stand and the head is off
</TD></TR></TABLE>But watch the video, the head is clearly on the engine.
Thread Starter
Joined: Mar 2003
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From: Brooklyn Park, MN
Re: (90blackcrx)
the head is on.. but it does that anyways even when the head is off.. i wonder maybe the rings are hitting each other... i didn't file gap the bottom two.. i check one of them and it was already in spec.. i did file all the two top.. to within spec... but hey has anyone ever buit it and hear that kinda of sound b4....
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From: Watertown, CT, USA
no no no, it's not your rings "slapping". And without a precise sound/video clip of you turning over your motor by hand and the noise I can't really diagnose it. My thrust bearings made a click noise after I put them in so I just took my crank out and repositioned them before torquing it down, might be something like that.
