420A Port and polish, valve job?

[shavers55]

If I was to get my valves 3 angle cut, would I also have to get a port and polish or any other type of head work done? Would it be a waste of money to just get my valves cut without any head work done. I'm planning on turboing my 420A on stock internals, just want to squeeze a little extra power out without doing and or spending to much, rather than doing a complete build. thanks

 

[junkyarddsm]

Their will be no gain for you at the 3 angle valve cut as the valves are already angled to start with. It has been talked about many times and if you look you will see that most machine shops do this when they rebuild heads. Bullerdsm is the one who I read the most on about the 3 angle job and he knows his stuff so look in some threads on the subject of (valve job). To also add no you would not need to port or polish but I recommend gasket matching your head, intake, and exhaust mani.

 

[BogusSVO]

A 3 angle valve job is done on the valve seat in the head casting. A back cut is done on the valve so there would be 2 angles on the valve instead of one.

http://www.dsmtuners.com/forums/cylinder-head-short-block/420045-how-have-4g63-head-rebuilt.html

This is on a 4g head, but the same would apply to your 420A head

http://www.dsmtuners.com/forums/newbie-forum/341288-why-have-your-valves-back-cut.html

As far as the port and polish, if you are not sure of what you are doing, mainly on the short turn radius. Do nothing more than the gasket match, as stated above, and smooth out any cast flashing in the runners and bowls.

 

[shavers55]

i wasnt going to do the port and polish myself.....as you can tell by my questions i am a super noob when it comes to this stuff..so what exactly is gasket head matching and what would that cost?

 

[BogusSVO]

Not Head gasket matching, but gasket matching, as in the the intake and exhaust gaskets.

When you place the gasket in place then remove the casting material the intrudes past the gasket opening and blend that in.