Just thought I'd share some of what I do, mostly for entertainment sale. We all like cool pics of cool stuff, albeit mostly Chebby stuff.
This is a set of heads I just finished for a Drag Week customer.
This is a set of AFR 335's we're using as a foundation. Ultimately they will get alloy seats, oversize valves (2.375/1.85) and steel guides with liners on the exhaust. The engine they're going in will be 588 ci, 11:1 pump gas, single carb with a Steve Johnson single plate capable of over 800hp of N20.
Portng room R&D
Once I got the ports how I wanted them, we changed seat material on these. These will have CHE alloy seats and steel ex guides w/liners. The intake seats are .100" deeper and already to size...I had to deepen the hole, but not make it any larger in order to maintain the right amount of press. Normally, I would order slightly oversize seats (like I did on the exhaust) but that would have been a 6 week wait. These were in stock. Made my job a little tougher, but doable.
The head goes in the mill with the seat pockets squared to the head via the magic fixture from Pete Graves CPMotorworks Inc. Instead of moving the head of the mill, I just set the fixture by indicating the bottom of the pocket flat. Once set, they should all be the same...or will be when I'm done. Then I indicate the diameter of the pocket on each one and bore to size with the boring head. IN this case, I didn't want to take as much as a tenth out of the existing pocket if I could avoid it, I just wanted to make them about .09" deeper for the new seats.
Once the seat pockets were bored, the intake seats were installed. Next step is to bore the exhaust seat pockets. Because they overlap with the intake seats, these had to be done in order. Intake first, then exhaust. This is done in the seat and guide machine. Exhaust seats were .010" oversize but I cut them down to .005" oversize.
Cutting exhaust seats to size.
Adding a slight radius and polishing the edge for installation.
Once seat pockets are bored to size, exhaust seats are installed. Next step...surfacer.
With all the new seats installed, heads get a minimal surface before valve job just to make sure they're flat.
After surfacing, it's off to the seat and guide machine for valve job, then hand blending. I use a Sunnen VGS20. We have two in the shop.
https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/30715531_1764112330319242_1235772574797922304_n.jpg?_nc_cat=0&oh=72e4fd39213c8bffed9a4f61ffcb1e7a&oe=5B2AE7CDI also do a little mod to the area around the spark plug. This is before, as from AFR...
And after...
You can also see the finish blending on the valve job.
Finished ex port...
And of course, the results; These are final on the prototype ports, I will flow the CNC ports for comparison before all is said and done. I might work on the ex port a little more. 2.375/1.85 Ti valves, 50* valve job, 4.60 bore.
....Right / left / ex
.2 152 / 152 / 126
.3 230 / 236 / 200
.4 300 / 307 / 260
.5 354 / 350 / 294
.6 400 / 385 / 306
.7 431 / 413 / 316
.8 446 / 429 / 324
.9 450 / 441 / 334
1.0 454 / 449 / 341
