If you are not familiar with SOAP, check out SOAP in WebSphere - Getting Started.

The soap.client.props file defines the SOAP timeout. By default, the timeout is 180 seconds (that's 3 minutes). If you change this value, you will want to restart the cell for this change to take effect.

com.ibm.SOAP.requestTimeout=180

When the timeout has been reached, a SocketTimeoutException should be recorded in SystemOut.log if using Basic Logging or in the HPEL log. 

[SOAPException: faultCode=SOAP-ENV:Client; msg=Read timed out; 
targetException=java.net.SocketTimeoutException: Read timed out]