My head port and polish job

[Gst18]

This weekend i was working on port matching and cleaning up the head from imperfections. So far i have only done the intake ports
I also evened out the seats to the head. I believe i did it correctly. As long as i don't touch the valve set face i should be fine right?
Please let me know what you think. Any tips or advice welcome.

Here are some pictures

 

[scottsee]

Thats per'd. Good job..

 

[1SloColt]

Looks really good. Did you just run a diegrinder with some carbide bits? What did you do to get the finish so smooth?

 

[GVR4592]

Looks really good. Did you just run a diegrinder with some carbide bits? What did you do to get the finish so smooth?

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

 

[Gst18]

Believe it or not I bought a kit from home depot for a dremel. I used that kit, then sandblasted the head to even out the uneven scratches. Then I used a small scotch brite rotary pad to give it a polish like look
.
It came out ok for the intake side. I'm more worried about the exhaust ports since its smaller in diameter.

EDIT: I also bought 2 carbide bits to get all the imperfections ground away

 

[BISHILVR]

Hope you plan on a valve job.

 

[rampridersrider]

Hope you plan on a valve job.

Just curious, but why?

 

[definitiveno]

With the increased flow of the port job decent gains can be found with multi angle valve jobs. In fact alot of builders argue that the biggest gains in general lie in the valve job.

 

[BISHILVR]

Well another reason is that it looks like he sand blasted the valve seats.

 

[bryanwheat]

No flow bench?

 

[1SloColt]

Most backcut valves or multiangle valve jobs I've seen really translate into low lift flow increases, not too much on the high end. I've seen certain heads lose high lift flow on valves jobs vs. stock cuts.

 

[BISHILVR]

Most backcut valves or multiangle valve jobs I've seen really translate into low lift flow increases, not too much on the high end. I've seen certain heads lose high lift flow on valves jobs vs. stock cuts.

That is more true than you know. Without a flow bench and LOTS of experience, 99% of backyard porting jobs end up in a loss of flow in one area or another or both. There is a reason good proven porting companys and the people that work for them get so much money for thier work.

 

[definitiveno]

That is more true than you know. Without a flow bench and LOTS of experience, 99% of backyard porting jobs end up in a loss of flow in one area or another or both. There is a reason good proven porting companys and the people that work for them get so much money for thier work.

He's not talking about porting

 

[BISHILVR]

He's not talking about porting

Well I am!

 

[Gst18]

Yes that was the main reason i didn't get the 3 angle valve job done until i finished porting the rest of the head.
Thanks for all the replies

 

[pj91gsx]

you did a really good job, but you can make the ports look like glass if you use cross buffs. You need the small ones. The big ones will not fit in the ports.

I use an air compressor tool and the cross buffs. the cross buff's rod will not fit into a dremel.

 

[pj91gsx]

did you port a lot on the lower part of the intake port? Mine looks like there is a hump there on my head

 

[Unreal89]

Wow, 2 years later you ask these questions?

 

[all_motor_mike]

brilliant! make the intake ports mirror smooth.

 

[pj91gsx]

your right. I need to read when the threads are posted.

 

[1AWD90]

I had a buddy just do a light port and a nice polish on his 1g head. He also did a 3 angle valve job. Anyways to get to the point he had about a 15cfm gain on the flow bench with this light port and polish.

 

[brute]

I had a buddy just do a light port and a nice polish on his 1g head. He also did a 3 angle valve job. Anyways to get to the point he had about a 15cfm gain on the flow bench with this light port and polish.

What do you consider "light" ? Like gasket matching? Or like not piercing water jackets?

 

[Boo5t_Addict]

I was reading an article about head ports on race cars, and they were talking about how a lot of builders (since the old days) tend to leave not a mirror finish, but a bit of roughness. The reason being, when it's not exactly smooth as possible, and a tiny bit rough, the air molecules that are touching the rough raised parts of the edges stay stationary, and trick the intake flow into thinking it's in sort of a venturi, thus increasing velocity slightly. If I could remember the article, I would bring it, but it makes sense in a way. Of course the article also stated that different builders use different finishes depending on the application, so a mirror-smooth finish could be just as good or better than one that has a slight bit of roughness. I can't remember, it's been a while, but it's something worth looking into if you want to get the most out of your setup. Every little bit helps, because when it comes to heads, velocity is key.

 

[pj91gsx]

i think that is very strange. I am still going to make mine like a mirror, because I just spend about 40 dollars on crossbuffs.

 

[T9S1i]

you do not want it to be a mirror finish!
It needs to be as rough as stock for the air and fuel to mix properly.

If this is your first port job, i would just remove casting imperfections and leave it alone.


Do a search on porting our 4g63t heads and you will see that they are not supposed to be mirror finished