lstvr

I have a new set of Dart 225's on my motor and will be camming it soon. How hard are you guys revving these springs to? I want to set the rev limit up to a safe limit, i have a soft and hard cut facility on my ECU, i had the cam custom ground and shift point should be 6600, with a redline of 6800. Can they handle this ok?

vettenuts

iTrader: (4)

What's the lift. Those springs should be the PSI 1511's with titanium retainers. They should rev that high no problem unless you have some huge lift. They will rev higher than equivalent duals.

JPH

iTrader: (2)

like vette said, aslong as valve springs and cam profile mix together, you shouldn't have any problems. What cam and springs?

lstvr

Had a cam specced for me 232/236 .625/.629, its being ground to run with my 1.85 rockers, so this is how it pans out at the valve end. I also noticed on the spec sheet it is XE lobes, easier time for my valvegear i assume with the higher ratio rockers. No bad thing. Just wondering what you can safely rev these to. I know theres no point going way past peak.

vettenuts

iTrader: (4)

I think you better run some numbers and measure your installed height. Those springs are excellent, but they are installed at approximately 1.765" (from memory) so I think you may hit or be close to coil bind with that cam. The springs will keep up with most any cam, but if you bottom them that's another issue. With that stout a setup, you may need something like a set of Crane 833's, which have a high seat value and more stiffness.

405HP_Z06

iTrader: (11)

The PSI 1511's were installed at 1.800" on my Dart 225's. Dart specifies these springs to accept .650 lift so you should be fine.

lstvr

I shall check when installed to be safe, ihad the the valves cut back in the head by 0.030 cos i was paranoid about PTV, so a bit more there too. But i will double check.

JPH

iTrader: (2)

cam is a good profile with your combo and will carry to 6800k, so your gonna need some good valve springs. I would run atleast 130+ on the seat. If I were specing this cam out and knew you were gonna turn it to 6600k+, I would have recommend dual springs IMO.

xBROKEx

iTrader: (7)

if you had dual springs youd be good to over 7k

JPH

iTrader: (2)

vettenuts

iTrader: (4)

The springs on the Darts are excellent springs, but based on your setup you really need to measure and figure it out. I put my setup into a spreadsheet to see the seat numbers and clearances with my setup. Since you have recessed the valves, you may find your seat values are very low since these springs don't have a lot of seat pressure at 1.8 and you are more than 1.8 you may already have an issue. I would take some measurements on the work bench prior to installation, its a heck of a lot easier.

405HP_Z06

iTrader: (11)

Looking at the PSI specs for the LS1511, I was incorrect. The specs for these springs are as follows:

LS1511ML Beehive
OD - 1.290"
ID - .630"
Seat Pressure - 120lbs@1.800
Over the nose - 360lbs@1.175
Rate - 384
Max lift - .625"
Coil Bind - 1.100"

So at 1.800" installed height with the cam you plan on running, you will have an issue.

JPH

iTrader: (2)

looks like you can only shim them .020 before you get into coil bind issuses.

lstvr

Its never simple is it!? I did a search on these springs and there was a guy running these on an LS7 and running .650 lift. I should tell him he's on thin ice too!!

vettenuts

iTrader: (4)

Katech loves these springs. They did a bunch of testing and selected them for their 427 packages. These are one of the best beehive springs out there, but like anything else within limits.

405HP_Z06

iTrader: (11)

Well, technically IF the springs were installed at 1.800, you could run .640 lift max.

1.800 Installed height - .060 minimum spring clearance = 1.740 safe installed height

1.740 safe installed height - 1.100 coil bind = .640 max lift

It seems that PSI specifies more clearance for safety.

lstvr

So would you say if my install is 1.800 or slightly more i can run them? I searched and found that Katech runs these to 7100rpm with .650 lift, install to suit obviously.

405HP_Z06

iTrader: (11)

Yes you could, but keep in mind that you would be slightly below (.010) the recommended minimum coil bind clearance.

lstvr

IF the valves have been cut back by 0.030 as my vendor says they have ( will measure to be sure.) then ok? Can you buy a valve spring tool and if what sort of money are they? Thanks

405HP_Z06

iTrader: (11)

I don't know if 'cut back' means the valves are sunk .030 or they took .030 off the margin. Either way, an additional .030 would put you in the black by .020. A valve spring height mic is roughly $60.

http://store.summitracing.com/egnsea...115+4294853226

You need the mic that measures 1.600" - 2.100"