LS Factory Stop Leak

[Pop N Wood]

Pulled the water pump on my LS2 crate motor to drill and tap a hose barb for the head vents. Noticed this plug of brown powdery stuff in one of the water passages. Found it interesting that GM ships radiator stop leak in their brand new motors.

 

 

I also learned that up until this year MSD did not make an ignition controller for LS2 motors. I had to return the LS1 unit I bought last year since it is only for LS1 motors. I don't think MSD even realized they were different until late last year.

 

Guess it is a good thing this car is taking forever for me to finish. Would have hated to have the car done but no ignition solution for the carb'd motor.

[gearheadstik]

You think that might be a type of water restrictor? I have a ls1 but have not seen anything like that floating in there.

[Pop N Wood]

No, it is really powdery. You can see dust from it all over the motor. It will almost certainly dissolve when water hits it.

[A. G. Olphart]

Aluminum castings can be pretty porous... IIRC that was a problem with the original GM 215 V8.

 

 

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[280zwitha383]

Wtf.

[pparaska]

That's a GM coolant "Tab". Also, many rebuilders put them in the water jacket before they ship out. The AL motors are a bit less forgiving than the iron ones, as I hear it. The "Tab" works for small leaks that occur at head gaskets, some small block porosity, etc.