66deuce

iTrader: (1)

i just read an interesting article by David Vizard in the newest issue of Popular Hotrodding,about the proper valvesprings/valvetrain setups for street cams.my question is this:

has any body gained power or extended the rpm potential of their motor from switching to a single behive 918 spring, from a dual spring setup?

the tests in the article were done on a SBC and a Ford 5.0 motor.i know about the proper matching of the cam and valvetrain, and stable valvetrain harmonics.just wondered if anybody has seen similar results in an LS1 motor?

PREDATOR-Z

Well from my personal old setup (LS6 valves, 918, tit ret. and Cometic .045), I was able to squeeze 404 out of a 224/220 Cam only.
So I would say, yes the lighter effecting moving mass has power gain potential in it.

66deuce

iTrader: (1)

yes the light weight will help,but i wonder if the beehive type springs have an advantage due more to better valvespring harmonics?

Xtnct00WS6

iTrader: (8)

so if you have a 224/220 ~ 224/224 you will have more hp with a single valve spring than apposed to a dual like the Comp 921?

PREDATOR-Z

It has not been proven, but I believe, yes (minimal of course)
The single Beehive do control harmonics much better at higher rpm, that I'm sure of.

Here is a good read:
http://www.krcperformance.net/newcontent/beehive.html

66deuce

iTrader: (1)

it's all about matching the springs to the cam profile,along with the rest of the valvetrain.too much spring pressure and you can induce lifter collapse.weak pushrods can flex,reducing lift and create harmonics issues.it's all about the combo.different cam profiles, or types of cams require a spring matched to the cam. Predator's car is a good example of a well thought out combination of parts,and attention to the little details is what gave him 400+hp to the wheels.i run the PP gold duals now,and i won't be changing them out in hopes of a few HP,just wanted to create a little discussion and see if anybody had done any testing or had positive results from switching from a dual to a beehive single spring on an LS1 motor.

66deuce

iTrader: (1)

thanks for the link.how's the car coming?

PREDATOR-Z

I finished it last night, but i was pooped, so I didn't start it. I was too tired to double check everything and I would rather do that one more time.

Everything good so far, I got tomorow morning off so it is start up time, fill radiator, couple of cool downs and hopefully off for a drive. 100 miles later, i will dyno.

All i have to say is someone should shoot GM engineers for placing that cowl so close to the motor with those spikes. You should see my hands, looks like I stuck them in a box with a freaked cat on PMS.

slt200mph

iTrader: (42)

FYI those spikes are push pin fasteners...you can get a pair of plyers and pull them up..anytime I am up under the cowl I do this first..it saves a lot of bloodshead...