I did these about 4 years ago and the only thing I knew was leave the floor alone, raise the roof, narrow the valve guide, and dig around a little in the bowl. Years later, after seeing pictures of GOOD ported heads, I now realize I didn't go nearly high enough with the roof. Oh well...



Knowing that different flowbenches flow different and all the variables associated with the process, I decided to flow the stock heads along with them at the same time for a good comparison.

Both heads were from a 93.


Stock/Ported




Intake
.050 ?/35
.100 62/63
.150 91/92
.200 122/120
.250 152/152
.300 176/179
.350 195/205
.400 211/222
.450 209/237
.500 206/245
.550 206/246


Exhaust
.050 23/25
.100 49/49
.150 77/75
.200 96/93
.250 114/113
.300 127/128
.350 137/140
.400 143/148
.450 147/154
.500 150/159
.550 152/162


Conclusion: I notice that I lost some flow down low on the exhaust(minimal). Maybe the ported heads flowed a little worse from the beginning, you never know. But I doubt it, and I'm not above thinking that I killed some low end flow! Overall, I'm pretty happy with the results. It looks like from .300 on up, they are gaining on both the intake and exhaust. I never thought they would have picked up what they did, especially at peak. They might make a little more power and they might not.

 

I am porting my heads myself too. Did you notice any difference in the power or have you installed them.

 

Haven't installed them, but I'm guessing that it'll have to pick up a little power.

 

got any pics and detail what to grind? It's funny because I was looking at the 3pc deburr kit on summit because I wanted to do this. Came on here and came across this thread.

 

Go to standard abrasive web site they have photo instructions, and a dvd instructional video you can buy summit sales the dvd also

 

I have some very old pics on here somewhere from back when I was doing them. At least years ago!

 

do you have any pictures, or other advice? i have a set id like to try it on.

 

I definitely don't need to be giving advice!

I'll get some pictures later on today.

 

A couple pictures. I need to take them outside in the daylight for some better shots...maybe tomorrow.

 

I'm no pro myself but the bowls look really nice. Good effort.

 

Not bad. There are a few nicks on the valve seats. You may want to have your seats ground or at least lapped before you put those back on and bolt them up.

Keep up the good work! Let us know how it runs after you put them on.

 

Already lapped them.

 

Intake ports are 180cc.