Ok i just got my Pro Lightning 64cc chamber 200 cc runner heads and they have single springs. They also have a note that came in the box that says "not recommended from roller cams". The only reason i got these heads was that they came with dual springs, so i could run my XR274R-12 solid roller cam. What should i do? I am already gonna call and complain, but what else?

 

well if the phone call doesn't get you anywhere all that's left is to return them or machine the spring seats out for larger springs, if they aren't already and run the springs you want. do thay have screw in studs or pull out studs? you need screw in studs.

 

They come assembled with guide plates and screw-in studs. They have 1.550" springs.

 

Well i just talked to the guy at Powerhouse, Rick. He said that if i'm under the max lift i should be fine. He also said that they went away from the dual springs and went with the single springs. They supposedly have a 130# seat pressure intalled at 1.880 with .100" longer valves. Do you guys think i will have any problems running them as they are, mainly valve float, and valves hitting pistons.

Thanks
ME Leigh

 

they use similar springs to the hydraulic grinds. They really arn't designed for 6500+ rpm and for that reason, should be ok with the spring installed.

 

Good thats what i wanted to here.

 

What does comp cams recomend for springs? Seat, open pressure, and rate. I'd use what comp cam recomends for springs.

 

Hey, how long did it take to receive the heads?

 

Wait a minute. I thought you could get an assembled version with big honkin dual springs for a roller cam.

To Quote Summit's catalog:

K3 kit: Designed for roller cams, this kit includes 1.540" dual springs with damper (190 lbs. seat pressure at 1.900"/450 lbs. open pressure at 1.300"), .660" max lift, chromemoly retainers, and 10* locks.

I DO notice however, that they just offer one generic roller cam version of the head, not the separate hydraulic roller and solid roller versions they used to. The above roller cam version looks very similar to the old solid roller version they used to list. And it's a very serious spring! You would destroy any hydraulic lifter with that much pressure- solid or flat tappet.

The milder K2 kit has 1.46" dual springs and only 135 lbs. seat pressure springs. They list it as being for solid flat tappet cams, but I suppose it would also work OK for a mild hydraulic roller as well.

 

It's been a while since I've looked but those dual springs from comp cams for that cam are only like 80 bucks and I believe they are 1.55 od also. Worth checking out and while the heads are off may be worth the peice of mind to get them.