Went back to the Dyno....
#21
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Damn that's good mpg for a cammed lt1. I have the same springs as you right now, the Howard 215s and I just didnt trust them enough for the cam I bought similar to yours, 230/240 .600/.602 on a 1.6 so I got duals to not worry at 7000. I'd love to see what you can put down on a track if you can get a 1.8x without popping the 10 bolt. Some bias ply 26x10.5s should soften the blow more than radials, but I still can't say how impressed I am that you put down those numbers on a mustang dyno. Your trap speed will tell the real story.
Last time I went to the track I used about 1/2 tank on 13 passes.
Your cam probably has faster ramps than mine; mine are 54/50, not overly aggressive but not too tame either. I'm sure that is helping me with these springs at those RPMs. They are 120 on the seat 375 open as installed IIRC.
#22
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According to some DA conversion calculators my 106-108 converts to114-117 traps at SAE conditions for 0ft DA. I still need to work on my launch to get my crappy times down. 13.3 sucks even at 6200DA with my set up. I'm on all seasons, but would like to crack 12s at least with my DA and tires.
I looked over some of my logs and I'm stalling my clutch release too long. The log will jump to about 20mph, then hover there for about a second, then continue accelerating. I need to get my foot too stop doing that.
Last edited by hrcslam; 08-28-2014 at 08:08 PM.
#23
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I called Howards Cams and verified the spring rates (120@1.8" and 430lbs/in) which gives me 128.6 lbs on the seat and 371.5 lbs on the nose as installed. I then called Lunati to verify these springs on my cam is good to 7000 rpms. They said yes, but the HR's are not. Damn. They told me my 6700 right now is the limit on hydraulic lifters.
Anyone revving to 7K on HRs?
Anyone revving to 7K on HRs?
Last edited by hrcslam; 09-11-2014 at 09:24 AM.
#24
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I called Howards Cams and verified the spring rates (120@1.8" and 430lbs/in) which gives me 128.6 lbs on the seat and 371.5 lbs on the nose as installed. I then called Lunati to verify these springs on my cam is good to 7000 rpms. They said yes, but the HR's are not. Damn. They told me my 6700 right now is the limit on hydraulic lifters.
Anyone revving to 7K on HRs?
Anyone revving to 7K on HRs?
The tech guys at Lunati/Crower laughed at my open spring rate with my cam on entry level LS7 or similar stuff.
#25
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I'm just wondering who's running hydraulic rollers to 7K? Don't LSx's do it all the time? We share lifters and springs. And the LTx has lower RR ratio's....
#26
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I can't tell, is this sarcasm? I could see NSA rockers and such, but for what I'm doing I shouldn't need link bars.
I'm just wondering who's running hydraulic rollers to 7K? Don't LSx's do it all the time? We share lifters and springs. And the LTx has lower RR ratio's....
I'm just wondering who's running hydraulic rollers to 7K? Don't LSx's do it all the time? We share lifters and springs. And the LTx has lower RR ratio's....
no sarcasm.
Thats a lot of open spring pressure and I assume a fairly aggressive ramp rate.
#28
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Not sure if it's worth the risk of going higher without seeing it on the dyno.....
How would you all go about testing for valve float? Or should I just leave it as is?
Last edited by hrcslam; 09-11-2014 at 05:18 PM.
#29
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Why did they laugh at your open spring pressure? Too low? Too high?
Last edited by hrcslam; 09-11-2014 at 06:18 PM.
#31
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Looking at your dyno curve is the most practical way I know of spotting valve float. If it tapers gradually after peak hp, rather than dropping suddenly or looking jagged, you're probably good.
#32
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Ahh, so torn.
Why you scared to replace the springs?
#34
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Something like this would be easy to pop a valve cover and check spring pressures without removing the springs. Hell, you could check them all every oil change with ease. I didn't know these existed until 5 minutes ago, it's now on my short list....
In Car Valve Spring Pressure Tester
Last edited by hrcslam; 09-11-2014 at 06:23 PM.
#35
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What he is getting at is that spring failures within the first few hundred miles are fairly common and then at the end of their life you get sort of a warning where they will usually float before breaking. He is currently seeing no float so why take the gamble on fresh springs. A friend lost a motor to this just this year, brand new set of Nexteks one broke at 35 miles and did no harm then one broke at like 135miles at low speed cruise on city street, heard a rattle went to roll down the window to hear better just that quick the valve broke then the rod. Had a lot of miles on the last set of Nexteks and they were allowing float.
On the lifters, I have run original LT1 lifters and the "Cadillac racing" ones to 69-7000rpm.
On the lifters, I have run original LT1 lifters and the "Cadillac racing" ones to 69-7000rpm.
#37
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1/4 vs 1/8 turn is splitting hairs. The idea for the bare minimum is just some insurance against (pumpup) hanging a valve slightly open in the case that you do get slack somewhere in the valvetrain.
Looking at your dyno curve is the most practical way I know of spotting valve float. If it tapers gradually after peak hp, rather than dropping suddenly or looking jagged, you're probably good.
Looking at your dyno curve is the most practical way I know of spotting valve float. If it tapers gradually after peak hp, rather than dropping suddenly or looking jagged, you're probably good.