My ported head picts

[Pablo]

After around 20 hours of porting I managed to "finish" my heads. I did a lot of experimentation with a home made flow bench and I just got tired of going back and forth.
In the end I ended up doing the only two things that actually made a measurable improvement on my bench.
I opened up the valve throat to 90% of the valve diameter, then blended it in and blended the short side radius.
I also removed as much material as I could from the biased side of the valve guide boss. I then "swirled" it around the back side of the guide. Just doing those two things and NOTHING else made a massive improvement in airflow.

I have extra heads and I tried flowing a port done up to look like what you would think would flow a lot, and that actually flowed substantially less than the port I did that looks like these pictures.

FYI surface texture means pretty much NOTHING to airflow. So all those picts that people go ga-ga over because the porting is a smooth CNC finish. That doesn't mean anything to airflow. The shape of the port is everything.

I also learned some interesting things that I might apply to future heads. Playing with clay I found that adding a large hump of clay on top of the short side curve increased airflow a lot. It also changes the sound of the port. You can hear a "smooth" flowing port vs one with turbulent airflow. It's kind of interesting to note that the port with the clay in it sounded very smooth.

One thing I added to these heads that I wasn't able to test is the tapered head bolt pinch point. I removed as much as I could from the top of the port and tapered it down to where nothing was removed at the bottom. Much of my research online has shown that this seems to be the way to go, and it kind of makes sense to me since I'd like to keep air up off the floor of the port.

These heads still need a valve job, and will probably get new exhaust seats at a minimum.
Speaking of exhaust, I couldn't open the exhaust throats up to 90% because seat is very wide and thus the bottom edge of the seat would be damaged if I went to 90%. I just opened them up to essentially the bottom edge of the cut. We'll see how it all looks with pressed in seats installed.

I also did a fair amount of chamber work. I'll let the photos do the talking.

Sorry for the photo quality. These are cell-phone picts. My digital camera does not want to work today for some reason.

Any comments/questions would be appreciated.

intake bowl

exhaust bowl

Polished chambers

This is a picture of the head sitting on the block. The chamber in the head is larger than the bore on the outside edge of the intake valve. This can't be good for airflow. Luckily, its in an area where there isn't a ton of airflow relatively speaking. I found this out by spraying some easy off through my bench and seeing where the easy off left a stain in my fake cyl bore. I'm still contemplating notching the top of the cylinder bore.

Here you can see how I only removed material from the top and just tapered it down at the pinch point. The picture doesn't really show it well.

 

[BandAid]

Wow those look nothing like my "ported" TTA heads ,great work you did....:wink:

 

[challengermike]

By smoothing the chambers does it change the CCs of the head alot?

 

[turbofabricator]

Now.......take a 3/8" oval carbide to the opposite side of the guide boss. Create a bull-nosed knife edge leading into the guide. The flow bench will show next to nothing, but at the track, it WILL improve power. Take the port walls out to a 1200 Fel-Pro and install bronze bushings in the push rod tubes. (doing this requires the intake to be ported accordingly, too, which will break out in at least one place. Use epoxy to fix it. Works GREAT!) Take the port out into the pushrod hole. Again, the flow bench will not show huge gains doing this, but the gains at the track will show it. Port volume is KING on a turbo engine. Remove almost the whole the exhaust guide out of the port, and cut the intake guide down about 3/16"-1/4", too. Widen the short side (both) as far as you can get it, but leave the lump in the intake port, just put a nice radius on it. Remember, you are trying to push the equivelent of a 800 HP small block chevy through those 6 TINY ports. It amazes me how much power these wimpy little heads will make.

Looks good so far. "FUN" isn't it!:biggrin: How's the dust in your corner of the shop? Do this for very long, and you will be coughing up black dust for years. Exhausting, DIRTY work head porting is! How are your fore arms holding up? Are your hands buzzing all night long? If not.....you aren't working hard enough.:biggrin: (or you're alot younger than me. )

 

[GARY HARVEY]

Cleaning up the combustion chamber is pretty much a fruitless exercise.
Ceramic on the chambers and valves and through the exhaust ports works BTW.
Someone in MI makes a cutter that does a good job of speeding up opening the pocket.

 

[Pablo]

Now.......take a 3/8" oval carbide to the opposite side of the guide boss. Create a bull-nosed knife edge leading into the guide. The flow bench will show next to nothing, but at the track, it WILL improve power. Take the port walls out to a 1200 Fel-Pro and install bronze bushings in the push rod tubes. (doing this requires the intake to be ported accordingly, too, which will break out in at least one place. Use epoxy to fix it. Works GREAT!) Take the port out into the pushrod hole. Again, the flow bench will not show huge gains doing this, but the gains at the track will show it. Port volume is KING on a turbo engine. Remove almost the whole the exhaust guide out of the port, and cut the intake guide down about 3/16"-1/4", too. Widen the short side (both) as far as you can get it, but leave the lump in the intake port, just put a nice radius on it. Remember, you are trying to push the equivelent of a 800 HP small block chevy through those 6 TINY ports. It amazes me how much power these wimpy little heads will make.

Looks good so far. "FUN" isn't it!:biggrin: How's the dust in your corner of the shop? Do this for very long, and you will be coughing up black dust for years. Exhausting, DIRTY work head porting is! How are your fore arms holding up? Are your hands buzzing all night long? If not.....you aren't working hard enough.:biggrin: (or you're alot younger than me. )

I realize this is what you told me in my original post about porting these heads. I'm just so tired of not having my car that I'm hesitant to put more work into them. I kinda wanna just bolt it together and go. I'm assembling my short block in addition to all this.

You think I'm leaving a whole lot of H.P. on the table by leaving the heads in their current state?

And yeah, I learned my lesson from porting my SBC heads about 10 years ago. I now wear goggles, coveralls, gloves, earplugs and a respirator. No more black snot or tinnitus... well, I still get ringing from the helicopters and guys bucking rivets near me without a warning. I think you probably know about that

 

[TBO]

The last set of these that I did I pretty much did the same thing. Doing the bowls and guide area was were I could give the guy the best bang for the buck.

If you really want to see some interesting stuff on the flow bench try different back angles on the intake valve. I have spent hours, yes mostly wasted but learning, on what the difference between a 30, 32, 33 and 36 degree back angles will do with a port design and valve job. It is impressive with such a small change like that will do, you wouldn't think much but I have seen number change as much as 20 cfm by changing the back angle and where it picks up what in the curve.

The tool that I think he is talking about is made by Goodson.

 

[turbofabricator]

well, I still get ringing from the helicopters and guys bucking rivets near me without a warning. I think you probably know about that

Huh?...did someone say something?

How much HP you are leaving behind is a tough call. I've seen 30 HP gains doing the above mods. Will you gain that (or more)? Hard to tell from pictures. Just remember, port volume is king. (though secondary to flow quality.) Contradictory, for sure. Clear as mudd PM me for my number and we can talk about it.

 

[charlief1]

What was the best change for the back angle on the valves?