jeepfun_tj

i was hoping these might work with ls6 springs whats Your thoughts.
Lunati 20540713 (Formerly Part Number 60513) GM V8 LS Gen III/IV, 3-Bolt Hydraulic Roller Voodoo 3-Bolt Core Camshaft RPM Range 1800 - 6400 Lift .549"/.549" Dur.@.050 217/223
i think lunati these lunati springs are speced for the cam.
Type: .600" Lift Ovate Beehive Valve Spring
O.D. Big End: 1.290"
I.D. Big End: 0.885"
O.D. Small End: 1.055"
I.D. Small End: 0.650"
Coil Bind: 1.140"
Seat Load: 130@1.800"
Open Load: 318@1.200"
Rate (lbs/in): 313
Quantity: 16
Part Number: 74818-16
Previous Part Number: 74818LUN
thanks

96capricemgr

iTrader: (1)

Not a stock GM cam, don't bother trying to use a stock spring. I know some vendors try to attract cheapskates saying mild low rpm grinds are OK with these springs, but if a good spring is not in the budget neither is a cam.

You probably aren't going to be using it's lightweight valves and you will be needing to spin more rpm, two BIG disqualifiers even before we consider an aftermarket lobe likely being more aggressive a ramp than a production OEM cam.

If you want a cam to use stock springs stick to a stock cam AND limit valve weight to what was used with that combination of cam and spring.

For example LS6 springs will NOT work right with an LS6 cam and stock LS1 valves because the LS1 valves are solid and heavier.

87gnx

iTrader: (3)

For example LS6 springs will NOT work right with an LS6 cam and stock LS1 valves because the LS1 valves are solid and heavier.

***Not true, they work fine. I've had two with no problems, winding up to 7k rpm.

99Bluz28

iTrader: (35)

The lobes on that cam have a ramp rate of 50, way to aggressive for the LS6 valve springs. I'd look for a cam that has at least a ramp rate of 55 or higher before even considering using LS6 valve springs. Even then I'd want better, stiffer springs.

A.R. Shale Targa

iTrader: (2)

Use the suggested springs for that camshaft as the LS6 springs have nowhere near those pressure specs. The Voodoo line of cams are more aggressive than a GM LS6 stick so even though the lift may trick you into thinking it will work....NOT the case.
A valve train is a system of engineered parts and needs to be matched correctly or the disaster can be catastrophic.

jeepfun_tj

ok looks like ill be going with better springs if i go this route. thanks everyone

brian_rs/ss

breaking a spring would be a lot more expensive than a set of good springs. plus better spring means more cam options.

96capricemgr

iTrader: (1)

Springs fail to work long before they break, many folks just don't know any better and assume their setup is great.

GM didn't do hollow/sodium filled valves because they wanted to spend more money.

jeepfun_tj

Great point! this is a budget build and yet i know i will want endurance. im not sure if there is any other budget routs other than just swapping to 243's. as for swaps as i prefer the 200 cc intakes for a tq build.

96capricemgr

iTrader: (1)

There is a lot of room to grow in cams before endurance is a problem.
Again talk to a vendor they can pick a mellow lobe and spring to handle it long term.

http://www.hotrod.com/how-to/engine/...st-comparison/
LS6/2 cam floated at 6200

jeepfun_tj

This IS one of my favorite articles!!! From this one and another i deducted that for low end torque ill want a IVC of 34 or under. 29.5 for the stock 5.3 tested. its Great info for sure and a lot of info can be gathered from that one thanks!!!

96capricemgr

iTrader: (1)

Oem cams are focused on 200K mile engine life, emissions, mileage, there is a LOT of room for improvement without compromises.
Also be aware displacement affects what rpm a cam peaks at.

kinglt-1

iTrader: (26)

I would not use LS6 springs for anything aftermarket. There is no point...130-150.00 will get you a quality set of beehives or duals from BTR or PAC. Valve springs are the last thing in a motor you ever want to skimp on.

Felix C

.550" was high lift when the LS6 cam was introduced. Spring tech. was the limiting factor.