afr valvetrain componet changing
 

hey everybody, i figured i would yell and see if i could get a few ideas on what all i am looking at to upgrade my afrs for more hp...

iv'e tried searching using "afr valves" and "afr heads" and came up with mostly "how will these heads do for my combo stuff' so i decided to ask you guys instead..

i want to install some manley raceflow valves with the matching comp valvesprings for my cam, the springs are a exact fit and have the same instaleed height of 1.75.. if memory serves. i was wondering if anyone has changed there valves and or springs and could let me in on the nessesary things that will need to be done.... i wasn't sure about the valve face angles, accoring to afr they come with the traditional 3 angle valve job, but is that 3 angles on both the valves and seats? or just the valves? i figured the manley race flo units i want to put in will have probably just a 45* face cut, and i don't want sealing probs... i figured while i had the heads apart i would take some cartridge rolls and smooth the cnc ridges on the ports, between this and the valves a person might see a 5hp per head increase?

also i am going to try and do a little cutting on the valve cover rails so my covers will seal properly, you figure for near 1300 to my door afr would have been a little better on them huh? lol..

well fellas i better get going, it will be awhile before i can get back to check so i will try and get bluegrassz to read the replies for me if it takes me a while to get back on....

well see ya later!

thanks... adam

A 3-angle valve job has slightly different angles on the valve and on the seat; IIRC it's 45° on the seat and 44° on the valve, but I could be wrong about the details.

The Manley valves come with a 3-angle cut on them. I don't know specifically about AFRs; but they match the cut on Dart heads basically perfectly. These things are somewhat standardized so I'd expect about the same on AFRs.

The Comp springs are probably part # 986 or 987, and are 1.45" OD. They should drop right in. You should use the Comp retainers, as they have different steps for the inners and outers, and may or may not be the same as whatever AFR supplied. Check installed height very carefully and shim accordingly. I'd recommend using the hardened steel shims such as from Manley or Comp rather than the usual kind you'd get at a parts store or something.

You can gain some flow by putting a radius on the valve margin. Usually valves come with a sharp angle there.

i heard that on the margin, but i am just trying to get what i can out of them before ever going to porting..... i don't feel like ruining a set of 1300 buck heads, and my luck i know i will lol.....

the spring i am wanting are the 987's, they are up to 600 lift and are the premium choice for my cam..... i'd like to put down500 flywheel, but i don't think that 282hr cam on a 112* lsa will do it, but the guy at afr told me i might make up for it with the 10.2: compression compared to the 9.5: 383 mule that westtech pulled 500hp out of... they used the comp 288hr cam in it.... hell if it puts out more than 450hp i will be happy:)

The margin is part of the valve, not the port. It's the area where the seat meets the face, around the very edge of the face. Depending on the particular valve, it could be an angle anywhere from 90° up to around 120°, and usually it's a sharp-cut angle, at the edge of the seat cut.