Hey guys time for a little destructive criticizm, I'm about 60% done with porting my Sportsman II's and would LIke to know what everyone thinks. These pictures Include 1 90% done head, and 1 head that I've only done exhaust on so far. I left the intake alone so you can see how horrible the stock casting was. Thanks for any comments

Porting<--click

 

ttt

 

Why leave the valve guide bosses like that? Looks to me like you just took the roughness off the casting, that wont do much.

 

That one there is a picture of the head with the least work

The other one has had the bosses ground on, and im revisiting them heavily, I wanted to get them both put through the paces, then go back and match them as close as possible. I've also got to be carefull considering that they're already 200cc heads, I won't survive if they get much bigger

 

Compared to what they look like when you're done, yes, the "as-received" look nasty. But, compared to factory castings, they look pretty good, especially the chambers.

This was my first attempt at porting/polishing. I was tickled with the results.

Just curious, what are you putting them on?

 

Although you've spent some time cleaning the roughness
out of the ports, you have not started to modify any of the key
areas nessessary to increase the flow of these heads. Don't worry about making the ports too big. Pick up some of the
good books written by David Vizard on head porting and
hopping up small block chevies. The diagrams and pics are pretty clear on what needs to be done.
These heads only have modest airflow "out of the box"
relative to the port volume, but when properly modified
you can get the intake cfm well over 300 in and over 200 ex.

 

Looks like you've just shined um up a bit to me. I looked at several of your pics, you should have did some cutting before you did all that polishing. You have a LONG way yo go.

 

Well i dont know how many of you have looked through some sportsmans....

But there have been modifications, and I'm not nearly done, just thought i'd catch some reviews while in the midst of the project

The short side radius has been lowered and shaped a bit, the bowls have been opened ALOT, the bottom of the valve seat had massive amounts hanging over, I just got back in from narrowing down the valve guide bosses, I'll post more pictures further along, but There's much more done than just a clean up.

Also these will be on a street driven vehicle, this isn't a track only setup and going to far beyond 200cc's probably isn't in my best interest, but I am however taking care of obstructions

Keep the criticism coming

 

If you are so concerned about port volume, you should have started with a smaller head. Like Chevy Bowtie's or some other 170/180cc port head. With Sportsman's "bigger is better".
Do not lower the floor of any of the ports it will not increase flow and causes turbulence which will reduce actual flow on a running
engine. These heads are kind of funny in that just about every thing you would think would help flow and power output, won't.
Like I said before if you want to get beyond a "bowl port job"
without exessive finished volume, there are key areas that need addressing. One of them is the valve guide and the area between it and the long common wall. This is where a flow bench helps or those books I mentioned.
These heads also are picky on camshaft timing. Some seemingly
good cam grinds just don't work well on Sportsman's, compared to others.

 

These heads are kind of a "make due with what you have" scenerio. Thats why I didn't start with a smaller port volume like would have been ideal. The next set will be smaller, and then ported back to about 200cc's, but for these I'm looking to do better than what they were stock. I dont plan on opening up the runners, bottom or ceiling, I do however plan on doing the things mentioned above. I garuntee what has been done so far will make more power than they would have the way I got them, and What i'll do from here will be the iicing on the cake, but I'm not smokey and sure dont expect a miracle. Just a strong streetable beast

 

Hope my criticizm hasen't been too distructive.

Good Luck to ya....

 

Doh, my ego took a hit, now its only twice as big as everybody elses

Just play'n

Thanks for the input thats what I was after

I just got back in (again) from working some more... you'd think they'd make more burrs/stones/mandrals that were longer than 1" wouldn't ya

Valve guide bosses lookin good, short side radius is about the max im comfortable with, it looks like its all opened up quite a bit, hope I still got my streetable low end

Im plenty open for lots more input, nows the time instead of after assembling it
Thanks guys!

 

Have you read this link? I got the kit from a local speed shop for $50.00. Sounds high until you go buy a dozen of the things individually.

http://www.sa-motorsports.com/diyport.htm

Good luck and let's see them when you're done.

 

Yea i have, and have reffered tons of people to it, its pretty good but you never really know porting till you're picking black boogers


I know what you mean about the price too, the price of 2 carbide burrs alone is more than that kit

 

Heh... now I wish I had ported my stockers when I had them off... Just went back on the motor today. Oh well, they will be on for a short time. Then come some badass ones for next summer

Hey, I envy you for porting your own heads. Its a task not many want to tackle. Good luck, I hope all goes well.

 

Get the book "How to build max performance chevy small blocks on a budget!" by david vizard barns and noble has it .It has a whole section on just porting sportsman II's

 

Hey man thanks!