Comp Cams Dual Conical SR Valve Springs

[digger]

durability question was more aimed at the general difference between the conincal and "traditional" style. i.e. which has the the lower operating stress

[Newold1]

Not sure that the durability status of either spring type is an issue for either type of spring although conical valve springs tend to have a different form of variable stress for the wire form and that does affect some aspect of durability however I have not seen any studies or data that proves the advantages of conical valve springs over other forms of valve springs. Maybe someone else here can render that data?

[bob460]

Good for 10,000 rpm on ls ......wow............tested by EFI University.

[Pete1]

Speaking of valve springs, did anyone here ever see a set of Isky SBC desmo heads when they were available?

[needforspeed66gt]

I've been using the 7228 single conicals with some of Billy's latest lobe profiles with great results, I have a set of these big duals going into an .800" lift drag race boat 540 here soon and expect to be happy with the results as well. Like Mike said, component weights are a huge component (F=MA), and I try to use as light parts as I can which allows for less spring pressure, which means less deflection in the whole system.

[bob460]

I think you would be better off with a smaller diameter PSI springs
That spring is 1.442" at the top, and 1.657" at the bottom.
It's 150 @2.00", 630 @1.200", and a 1.115" Coilbind

You'd be better off, going with a spring that gets the overall weight of the spring down.
PSI # CT1575ML: 1.400" Diameter at both ends
It's 150 @2.00", 625 @1.150", and a 1.100" Coilbind
With the reduction in spring weight, you don't need as much spring rate to control the valve, and lower spring rate causes less valvetrain flex.

Mike do you know what the PSI 1575ML weighs?

The dual conical weighs 150 grams with tool steel retainer.

[Orr89rocz]

Any one else use these 7245 conicals? I have only found some mag articles on a bbm using a rather aggressive 266 deg .473” lobe lift cam to 7500 rpm on a 2.19” valve and the ls motor that was spun to 10000.

I like the concept although pricey

[EDC]

Any one else use these 7245 conicals? I have only found some mag articles on a bbm using a rather aggressive 266 deg .473” lobe lift cam to 7500 rpm on a 2.19” valve and the ls motor that was spun to 10000.

I like the concept although pricey

Worked extremely well on a set of Higgins Ford heads.

[Orr89rocz]

Any one else use these 7245 conicals? I have only found some mag articles on a bbm using a rather aggressive 266 deg .473” lobe lift cam to 7500 rpm on a 2.19” valve and the ls motor that was spun to 10000.

I like the concept although pricey

Worked extremely well on a set of Higgins Ford heads.

Do you set them up like typical springs, .050-.070 from bind or does that not matter as much since the coils are all different so frequencies are variable. Less likely to reach a harmonic vibration