Max lift
#1
Max lift
Hey guy's does anyone know what a stock D3VE Valve Spring will start to bind up at meaning lift, or what will they take as far as lift from an after market camshaft,..........I have a 514 max lift wondering if the stock springs will work thanks...........just a question i was hoping someone could help me with.....
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Join Date: Jan 2000
Location: Crooked River Ranch, OR
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Max lift
I personally would not install that much lift with stock springs without at least checking for coil-bind. Also if your stock springs have more than 10-20K miles on them you'll probably drop 500-1000 RPM in maximum RPM before encountering valve-float. Broken springs tend to damage an engine extremely fast! Deen
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Hot Boy,
I posted that I wouldn't run the higher lift cam with the stock valve train...that is a personal thing because I wouldn't feel comfortable doing it and I like to only have to fix something once. Obviously some have done it and have had no problems or are just lucky. I have never liked to gamble...
If your running stock rods and pistons they will be the limiting factor anyway as your taking a big chance to spin them more than 5500 RPM. A rod bolt will probably be the first to fail and your stock springs should not valve float at that low of RPM. Deen
I posted that I wouldn't run the higher lift cam with the stock valve train...that is a personal thing because I wouldn't feel comfortable doing it and I like to only have to fix something once. Obviously some have done it and have had no problems or are just lucky. I have never liked to gamble...
If your running stock rods and pistons they will be the limiting factor anyway as your taking a big chance to spin them more than 5500 RPM. A rod bolt will probably be the first to fail and your stock springs should not valve float at that low of RPM. Deen
#7
Max lift
Hey thxs Deen once again,but i was just wondering what was a safe valve lift looking more for a number such as the 512.....or 490's,just trying to find what those springs will take before they start to coil bind,.........I've ran a small block 306 with stock valve springs with a comp 280/512.....lift,so i was wondering if the 460 would take the same or more even,i agree with u on the changing of the springs to match,i delt with that on my B.B.Chevy its got a .578,TRW POPups and all that and i had to change the springs on it,but with the 460 being a flattop motor i thought it would take a little more lift .......thanks
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#8
Max lift
The best method is to replace your valve springs with springs recommended by the cam manfacturer. A higher lift cam, for optimum performance, requires different open and seated spring load ratings than a stocker. When a machine shop does a typical valve job, their only concern is installed spring height. Spacers are often used to achieve correct height without concern for open and seated spring load pressures. Springs do get old and lose their tension.
If you haven't installed the heads, it's pretty simple to change the springs, about $100 for new aftermarket springs on a mild application. I've replaced springs on BBCs and BBFs with the motor installed and that's a real nasty four hour job with an air compressor and adequate beverage supply. With pedestal D3 rockers, you could probably do it in 3.5 hours.
Like Deen, I feel doing something right is the best way to avoid doing it twice, but that's a personal opinion. Cam grinders will normally void any implied warranty if new, correct springs are not installed.
If you haven't installed the heads, it's pretty simple to change the springs, about $100 for new aftermarket springs on a mild application. I've replaced springs on BBCs and BBFs with the motor installed and that's a real nasty four hour job with an air compressor and adequate beverage supply. With pedestal D3 rockers, you could probably do it in 3.5 hours.
Like Deen, I feel doing something right is the best way to avoid doing it twice, but that's a personal opinion. Cam grinders will normally void any implied warranty if new, correct springs are not installed.
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