DIY port and polish

[92pearltt]

So today I got bored and decided to teach my self how to port and polish heads. Did some reading and research online. I have a couple junk heads laying around so I figured I would just start practicing. I think it turned out pretty good. I really need to get an electric grinder cause something is wrong with my compressor and it is constantly running. But here a couple crappy cell phone pictures.

A few questions I have:

What is an acceptable difference in flow numbers on a flow bench?
I read not to gasket match the exhaust ports because the head port is smaller on purpose so its kind of like a wall for exhaust pulses, is this true?

Also any other advice and such is more than welcome.

Before:


After:

There is still a bunch of shavings in there thats why the back still look rough.

If anyone has any junk heads they are looking to get rid of for free or really cheap let me know.


Vince

[Constant_Project21]

Wow, that's a pretty good job, especially if it's your first time!

[92pearltt]

Thanks man, its takes forever haha. I need to get a tool to take the valves out, then I can do a better job.

[Constant_Project21]

For sure takes time. I have a head that's had some halfass port work I could sell ya haha. Pretty much bare, no valves and such.

[Goat Blower]

The thing is, porting and polishing work really well on some iron Chevy heads, they don't make much of a difference on DSM heads, because they are so good from the factory. The only real benefit on DSM heads is cleaning up the bowl area, for which you need the valves out for, and just a very light clean up of the casting boogers on the intake ports, barely even that for the exhaust ports. Bone stock heads have gone 9's, fairly stock 2G heads have gone 8's.

[92pearltt]

They are actually for my stealth.