I tried to install a crane valve springs 10308 kit on my new AFR 190s this weekend, but they won't fit. According to the crane website the springs in the kit are 99893 which it list as having a 1.46" outer diameter. When I measured the springs with calipers they were alot larger than 1.46". I need springs that will handle .555" of lift, and will fit in the AFR pockets. Do you think I can get away with using the AFR springs which are rated to a max lift of .550"?

 

i think you are supposed to get he 10308-1 kit...notice the dash 1.

why didnt you go with comp 987s and a all the necessary parts? that spring is rated at .600. Nu-tek sells a kit for $175. there is also a vendor on here now that is selling a spring kit for $90 i think that is supposed to handle .600 lift but i already bought the comps and i know they work so just added security i guess.

 

I certainly hope so. I'm running single springs rated at 550 and my cam on the exhaust side, w/ 1.6RRs is 552.

It seems to me that there is a margin of safety built into the max advertized numbers. I.e, a 550 spring is probably good to 575+-.

I say this because I doubt that every spring is the same in a set and they probably don't measure the pressure on each and every spring.
So the max number is probably a no less than, average number. JMHO.

 

I did buy the 10308-1 kit. It even says LT1 350 on the box. I'm not sure I trust the AFR hardware. I replaced the 3/8"studs with 7/16" studs and reused their guideplates. When I torqued them down to 50ftlbs, the guideplates cracked. So now I question the quality of the springs.

 

How can you crack a guide plate

 

you would think hed pull the threads out of the head before the guideplate cracked.

 

The problem lies in the design of AFRs guideplate. There isn't an equal amount of material around the stud hole. The two stud holes are on the outside, and in between them the material has been punched out in a semi circle. When they cut out the semicircle area, it cuts out part of the material near the stud hole. So you have about 1/8" of material on one side of the stud, and 1/4" on the other side. The guideplates are also hardened, which makes them brittle. I'll try to post a pic this weekend. By the way the threads in the head are fine. Didn't harm them a bit. It was a good thing I had a set of CompCam guideplates lying around.

 

The guideplates supplied with the AFR heads are specific to those heads. If you look at them, one pushrod slot is longer than the other. This slot goes on the exhaust side. If you compare the AFR guideplate to a normal SBC guideplate, you'll see that the pushrod slot spacing is different. By using a regular SBC guideplate, you may have issues with pushrod binding against the intake port, or roller rocker misalignment with the valve tip.

 

thanks, I'll look into that.