I hear my engine from the inside like a diesel engine ( not too loud...)when idle, in the outside the sound is normal. My mechanic sayed that it's a normal noise from the pistons.
mines are flat SRP, the engine works just great, normal idle and a lot of torque. No problem aparently just that noise. Normal?
i forgot i'm on stock cam again.

 

Does it go away at all after operating temp is reached?

 

It sounds all the time, not sure if it sounds louder when cold, the car it's out of termostat to prevent a overheating, so i it have not past the half of temp range to see if the sounds go away, i have now 500 miles after rebuid, but i think i'm not going to reinstal the termostat since the car is operating in 180 aprox in winter. what do you think?