LS3 Lifter noise or Piston Slap?

[IBLOWN]

Yeah most of the noise goes away pretty quickly after say 1min, but its still there for about 5mins, then i cant notice it. Its all about temperature of the weather. Wont do it in summer.

I keep leaning towards piston slap, but the speed of the noise is about valvetrain speed. Its just too deep sounding for valvetrain noise IMO.

I sort of proved it yesterday too. I let idle for a few mins, was noisy. Stopped the motor and pulled the belt off (took maybe 2mins), started it, noise was same. Took me a while to get the bloody belt on again because of the heat, but when i started it again the noise was gone. Leads me to believe the heat soaked into the piston while the motor was off.

 

[Martbar]

Yeah most of the noise goes away pretty quickly after say 1min, but its still there for about 5mins, then i cant notice it. Its all about temperature of the weather. Wont do it in summer.

I keep leaning towards piston slap, but the speed of the noise is about valvetrain speed. Its just too deep sounding for valvetrain noise IMO.

I sort of proved it yesterday too. I let idle for a few mins, was noisy. Stopped the motor and pulled the belt off (took maybe 2mins), started it, noise was same. Took me a while to get the bloody belt on again because of the heat, but when i started it again the noise was gone. Leads me to believe the heat soaked into he

 

[07GTS]

alloy blocks echo noises all around so could be starting anywhere, i thought mine had a knock in the bottom end so thought id investigate when engine was out and all looked fine, i then could relate it to the blower coupling had a little play in it at idle it would just rock a little causing it even tho it sounded like it was deep in the engine

 

[Martbar]

Our motor is the standard L76 and at start up the slap noise can be concerning(especially in the garage), the thing is as these motors wear the noise will only get worse. I've read in another forum thread that the slap can be tuned out. They retard the timing, has anyone had this done and how much difference did it make.
Depending on how much they retarded the timing your going to lose h/p as well.
,

 

[Pollushon]

Yeah most of the noise goes away pretty quickly after say 1min, but its still there for about 5mins, then i cant notice it. Its all about temperature of the weather. Wont do it in summer.

I keep leaning towards piston slap, but the speed of the noise is about valvetrain speed. Its just too deep sounding for valvetrain noise IMO.

I sort of proved it yesterday too. I let idle for a few mins, was noisy. Stopped the motor and pulled the belt off (took maybe 2mins), started it, noise was same. Took me a while to get the bloody belt on again because of the heat, but when i started it again the noise was gone. Leads me to believe the heat soaked into the piston while the motor was off.

Yep. As the owner of a stroker (aka slapper) that last vid def sounds like slap

Slap sounds bad but it's nothing to worry about. Just never flog it cold. My previous LS slapped is way to 300k and is still going strong in another car. The current build has been slapping since km zero

 

[07GTS]

Our motor is the standard L76 and at start up the slap noise can be concerning(especially in the garage), the thing is as these motors wear the noise will only get worse. I've read in another forum thread that the slap can be tuned out. They retard the timing, has anyone had this done and how much difference did it make.
Depending on how much they retarded the timing your going to lose h/p as well.
,

the piston slap spark table adds to the main spark to increase torque to the piston to help stabilize it to stop the slap, too retarded timing will cause alot of heat too as well as less torque

 

[Martbar]

the piston slap spark table adds to the main spark to increase torque to the piston to help stabilize it to stop the slap, too retarded timing will cause alot of heat too as well as less torque

I don't like noisy engines if it would cut the start up rattle in half l would think about getting something done about it. Are there any negatives that come with the increased spark?
Also wondering why they didn't do this to the noisy engines while still under warranty.
Cheers mate.

 

[07GTS]

I don't like noisy engines if it would cut the start up rattle in half l would think about getting something done about it. Are there any negatives that come with the increased spark?
Also wondering why they didn't do this to the noisy engines while still under warranty.
Cheers mate.

what i think they may do is fire it so its boarder on too advanced so it add pressure to the TDC revolution maby helping it, depends on the skirts too as they get short now days for power and a little less stability on the BDC rotation when cold as it flops, not all noises are bad or mean something bad is going on cold engines are going from sometimes 0c deg to 90c within 10-15 mins the block, cylinder, crank, rods, pistons, cam, valves ect are all different metals expanding at different rates until they hopefully get to where they are ment to be at operating temp, thats why when the big builds bore out the cylinder to match the piston its based on the boost it will see and rpm to work out the heat it will be working in which then determines how much it will expand in the bore

 

[IBLOWN]

the piston slap spark table adds to the main spark to increase torque to the piston to help stabilize it to stop the slap, too retarded timing will cause alot of heat too as well as less torque

I had the car tuned back in 2018. But the noise didnt start until about a year and a half later.

 

[IBLOWN]

Checked every rocker at base circle. No up and down play on any of them.