Anybody install a decomp in a non-decomp head?

[av8or3]

Has anybody drilled and tapped the boss on a non-deco cylinder head and installed the decomp valve?
Got a 262xp that’s needing it.

 

[redline4]

I think either @drf256 or @Redfin have?
I recall a thread where someone did it..just don't recall who.

 

[jacob j.]

I've done one, a 288 - it's easier if you have a bottoming tap and use a small bit to drill the pilot hole that will actually pierce the plating.

I put a piece of duct tape on the cylinder wall and used a 1/16" bit slowly to minimize flaking.

 

[huskihl]

I’ve done it, but only in the top of the combustion chamber.

I’d think what jj did would work fine. Just don’t blow through the plating very hard

 

[Redfin]

Pilot, use a diamond burr on the plating side out to roughly the thread diameter.

 

[Al Smith]

That brings up a conversation ,now think about this .Those who cut down the top of a cylinder to decrease the size of the combustion chamber cut off the plating if it has any .An aluminum block automotive engine cylinder head has no plating nor do small engines like Briggs and Stratton .

 

[qurotro]

That brings up a conversation ,now think about this .Those who cut down the top of a cylinder to decrease the size of the combustion chamber cut off the plating if it has any .An aluminum block automotive engine cylinder head has no plating nor do small engines like Briggs and Stratton .

Then the top piston ring would ride on the place where the piston crown used to be which is no problem when people cut only 0.02~0.05 inch.
Aluminum block cars have platting on them or a steel liner. Even the Briggs and Stratton use iron liner as an ad for their commercial engines.

 

[Al Smith]

Read my post again .I wasn't talking about the cylinder but rather the cylinder head .BTW It's not a steel liner it's nodular iron cast in place, not removable .It's all done with a die cast machine and robotics .I saw the process at Honda Anna Ohio and the machining process at both Honda and Ford Motor from which I retired .

 

[qurotro]

Read my post again .I wasn't talking about the cylinder but rather the cylinder head .BTW It's not a steel liner it's nodular iron cast in place, not removable .It's all done with a die cast machine and robotics .I saw the process at Honda Anna Ohio and the machining process at both Honda and Ford Motor from which I retired .

I saw the Toyota one. Yea they are cast in the block. What's the benefit of platting the head?

 

[Al Smith]

On a chainsaw it's not really a head but a head deck so to speak because the head and cylinder are a unit. If it is plated which I doubt it would not make any difference if you broke out the plating because for all intents it really doesn't help anything .