Metal clanking sounds at idle

[Jaycee604]

Hey guys me again back at it with a unique question. Just finished building a new engine, i have noticed that during idle it has a weird metal clanking sound, almost louder than exhaust. It completly goes away at half and full throttle and is very smooth. I put quality work into this engine, a part of me is thinking that it needs to wear in. I can supply details of engine if needed. Thanks for the help guys. And no the piston is not hitting the head. Everything is nicely filed off on the cylinder and piston too.

 

[wrench]

Could be some piston slap, Maybe the PTSWC is close to the maximum specifications

 

[Jaycee604]

I allready have two head gaskets and the squish is decent. What is piston slap and what is ptswc

 

[wrench]

PTCSWC piston to cylinder side wall clearance
.
When the clearance is close or at the maximum specifications some piston slap can be heard

SLAP- The piston skirt slapping the cylinder wall

CLEARANCE- distance between the piston and cylinder wall

Slap usually causes no damage but makes piston music

 

[wrench]

Hey guys me again back at it with a unique question. Just finished building a new engine, i have noticed that during idle it has a weird metal clanking sound, almost louder than exhaust. It completly goes away at half and full throttle and is very smooth. I put quality work into this engine, a part of me is thinking that it needs to wear in. I can supply details of engine if needed. Thanks for the help guys. And no the piston is not hitting the head. Everything is nicely filed off on the cylinder and piston too.

If your gas octane rating is too low you can have Knock and Ping
Knock - is some fuel igniting on the compression stroke before ignition
Ping - is the fuel igniting from the spark
Knock and Ping sounds like a metallic clack

Some guys add octane boost to their gas

If you made your cly head high compression burn a higher octane gas 91
But most M/B kits are low compression and can burn 87 octane without having a Knock and Ping