How far should I go with head work?

[deutschman]

Anyone have any good ideas on how far I should go in terms of head work?
Is it worth it to port and polish? I have read that the m20 head flows very well in stock form, and can not be improved on very much... True?
Valves seated, head resurfaced?
I am going to run a 272 cam, Miller chip, M30 AFM, and 19# injectors.

Thanks

[xwill112x]

the most gains from the head are to be made at the valve seat, so anything else other than that is probly just pissing money away.

[deutschman]

Good to know. Thanks.

[nando]

You can also improve the bowls and intake short side radius. Its ok to polish the exhaust and combustion chamber, but definitely dont try to hog out the ports. It can be worth doing larger valves but only if your other ducks in a row.

[deutschman]

You can also improve the bowls and intake short side radius

how is this done? more detail? the radius that you put on the entry into your intake manifold runner?

i don't think i will need larger valves.

[nando]

With a sanding drum usually ;)

Seriously, a google search will answer those questions better than i can.

[deutschman]

googling now.

[morerevsm3]

885 head flows enough to support 222 flywheel horse power at .300 lift standard, minor but worthwhile gains to be had from short turns, bowls and seats, and some porting on exhaust ports

[deutschman]

thanks. dont think i will have over 222 horses with the modifications i am running.
now i know what to ask for/talk about when i bring the head in.

cheers

[MR 325]

Don't let the others nay-say porting. Do it.

A friend has done it for me on all of my M20 heads.

[xwill112x]

not nay-saying, but most of your power is gained from the valve seat. straighting out the bends helps as well, just gotta be able to keep your velocity while gaining volume.

[deutschman]

I am going to do this work by my self.
-gasket match my intake ports (involves taking only a very small amount of materiel off around the mouth of the port)
-get rid of all sharp angles in intake ports and bowls (not much to do here)
-bias intake/exhaust ports (not sure if i want to mess with that...)
-lay back valve shrouding, polish chambers
-performance prep valves

http://www.allpar.com/fix/holler/head-porting.html

http://www.allpar.com/fix/holler/valve-prepping.html

I wish I could add the grooves to my intake ports but I think with the wrong tool that could get messy fast.
I ordered this today with some carbide bits.
From what I have read I think getting rid of as many sharp angles as possible, and keeping a nice rough surface to induce better air/fuel mixture is good enough for street motors.

http://www.dremel.com/en-us/Tools/Pages/ToolDetail.aspx?pid=4000-6%2F50

Hogging out or porting out the intake ports is not the best idea, unless you are biasing them to induce a spiraling air effect in your intake ports. They just do not need it unless you are going for very large HP numbers. Plus a real port job involves welding the original ports, and cutting new ports with a more direct airflow path to the chamber into the head.

[Brandon12V]

You're gonna run a miller chip.....................with an m30 AFM..............................?

[digger]

there are easy gains on the exhaust side, on intake side you don't seem to see anything overly impressive in terms of flow numbers.
There are not too many places that want to try out different things like raising the port and filling in the areas of the port that need it.
you want to increase the flow wihtout adding more volume to the port especially on a small cc M20

[nando]

there is excellent info here:

http://www.e30tech.com/forum/showthread.php?t=75938