TR2/3/3A Aluminum plug intop of cylinder head...

[karls59tr]

Did i read somewhere that this plug is destroyed when the head is hot tanked. Also is cleaning a cylinder head by degreasing and power washing good enough to prep a cylinder head or is it risky short cut?

 

[TR3driver]

I think the real question is why you wouldn't want to replace that plug anyway. They corrode from the inside out (dissimilar metals exposed to water) and when they blow, fill the crankcase with coolant.

That said, I've never had a head hot tanked, and never had a problem caused by that (as far as I know anyway). But be sure to remove the oil passage plug on the LR corner and make sure the passages are clean and clear.

 

[CJD]

It depends on the solvent your machinist is using. For cast iron parts, they used to use a very caustic solution, as it cleans better and faster. This can dissolve both titanium and aluminum. For aluminum they will use a less caustic solution that will not damage aluminum parts.

Now days most engines are all aluminum, so I doubt there are many shops still using the hard stuff. But, to be sure, it would be best to let them know there is aluminum on the head.

 

[karls59tr]

I think the real question is why you wouldn't want to replace that plug anyway. They corrode from the inside out (dissimilar metals exposed to water) and when they blow, fill the crankcase with coolant.

That said, I've never had a head hot tanked, and never had a problem caused by that (as far as I know anyway). But be sure to remove the oil passage plug on the LR corner and make sure the passages are clean and clear.

I just read that you could screw in a brass pipe plug to replace the aluminum one.

 

[TR3driver]

Or even a cast iron plug. ISTR you have to tap the hole, though.

 

[TRMark]

Use a 3/4-14NPT to "clean up". Very close to BSP tap in the head.