Single beehive vs dual spring
They only reason I am asking is because I have a cam with .609 max lift and the new 918s are good up to .625.
Which would be better for a .609 max lift cam thats willo rev to 6.8k?
The reason I am asking is becasue its about a 100 dollar price difference
If I'm wrong, someone feel free to correct me
Trending Topics
The Best V8 Stories One Small Block at Time
Duals providing a backup is a false notion. If you need the rate of duals for high rpm, (1) if you break the outer, then the inner alone won't be enough to keep the piston from kissing the valve, and (2) most of the extra rate is lost on the extra spring mass and the much larger retainer.
Dual springs are 1960s tech. Ancient, out-dated, obsolete.
If you want something more than the 918, well, COMP makes beehives intended for the BBC, any good machine shop can help you use those.
Duals providing a backup is a false notion. If you need the rate of duals for high rpm, (1) if you break the outer, then the inner alone won't be enough to keep the piston from kissing the valve, and (2) most of the extra rate is lost on the extra spring mass and the much larger retainer.
Dual springs are 1960s tech. Ancient, out-dated, obsolete. If you want something more than the 918, well, COMP makes beehives intended for the BBC, any good machine shop can help you use those.
My cam requires a springs that has 150lbs on the seat, a rate of 500lbs/inch and handles a .621" lift.
What comp beehive should I use?
Actually I went with the torquer v2 .595/.598 lift and even though the 918's (PAC or Comp) are rated to .625, the safety range is .600.
I read about a problem they had with Comp 918's. Several had broken, maybe less than 20 instances on all different types of engines and Comp had taken care of every claim. Never said they fixed the problem, still being manufacted down in Mexico as far as I know. Which is where they went after PAC quit making Comp's 918's.
Because I did not trust the .600 safe range, even though I could say it would hold .625 I went with an option Texas Speed had for a single behive that was rated safely at .650 lift. It is made by PAC but I don't know the part number. I checked every single spring rate and they were dead on. I'm very happy, they are installed on the heads now and waiting to get this project done.
So to answer your question ^ maybe not a Comp beehive but a PAC .650 beehive may be your answer?
both types of springs have their place.
a dual spring isn't necessarily "safer" than a single beehive.you can drop a valve just as easily with duals.the second,inner spring should never be considered a "backup"to the outer spring,that was never it's intended purpose.
more importantly is setting up the valvetrain properly(proper spring height,seated pressures,etc.)
Next set springs were duals, no doubts. And don't go cheap seats either. Do the homework and get a quality set of duals that meet your needs, not the flavor of the month.







...just received them yesterday...very nice kit indeed 