LT4 spring coil bind height?
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St. Jude Donor '04-'05-'06-'07
LT4 spring coil bind height?
Anyone know it? I've found this spec for aftermarket springs but can't seem to for these. I know the safety margin I need at max lift but would really like this spec if anyone has it. Trying to make some new valvetrain set-up decisions.
Melting Slicks
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From: NW Chicago Suburbs
Factory claims 0.525" is the max lift, I don't like these springs because:
- They're light on the pressure, easy to float the valves and break a retainer.
- The retainers are not very strong.
They're good for a LT1 1.6 rocker upgrade with a stock cam/redline, but if you're thinking about anything else, time for some aftermarket springs.
If you are machining the heads, it's easy to find good springs. If you're not machining the spring pockets, then there's only 4 options I know of:
- Stock LT1 or L98 springs
- LT4 springs
- Crane has a set, can't remember the number
- Comp Cams has 2 different sets of beehive ovate springs...
I went for the beehive set with Ti retainers.
Eric
- They're light on the pressure, easy to float the valves and break a retainer.
- The retainers are not very strong.
They're good for a LT1 1.6 rocker upgrade with a stock cam/redline, but if you're thinking about anything else, time for some aftermarket springs.
If you are machining the heads, it's easy to find good springs. If you're not machining the spring pockets, then there's only 4 options I know of:
- Stock LT1 or L98 springs
- LT4 springs
- Crane has a set, can't remember the number
- Comp Cams has 2 different sets of beehive ovate springs...
I went for the beehive set with Ti retainers.
Eric
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St. Jude Donor '04-'05-'06-'07
The spec I'm looking for is the compressed height of the spring when/where bind actually occurs. Example, an aftermarket spring might list it at say, 1.15.
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I am going from 7 year old memory so don't hold me to these numbers. The installed height is 1.780. The max lift is .525. This leaves 1.255. If I remember correctly this left about .060 before the spring stacked solid at about 1.195
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St. Jude Donor '04-'05-'06-'07
Originally Posted by silver & red CE
I just measured one off my 96, it's at ~1.200"
Last edited by Corvette Kid; Nov 13, 2004 at 10:06 PM.
Melting Slicks
Joined: Jan 2000
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From: NW Chicago Suburbs
It's hard to measure the crush without wasting the springs. I don't care if GM says it's OK, I wouldn't use LT4 springs on an LT4 HOT cam. I'm dumping the springs with a stock LT4 cam, I just don't trust them, IMHO the pressure's too low and the cast retainers are weak.
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by silver & red CE
It's hard to measure the crush without wasting the springs. I don't care if GM says it's OK, I wouldn't use LT4 springs on an LT4 HOT cam. I'm dumping the springs with a stock LT4 cam, I just don't trust them, IMHO the pressure's too low and the cast retainers are weak.
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St. Jude Donor '04-'05-'06-'07
Originally Posted by silver & red CE
see sig, no machining for the beehive ovates
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St. Jude Donor '04-'05-'06-'07
To answer my own original question, 
the LT4 spring bind spec is 1.22. Not good if installed at factory height of 1.78 and running a Hot Cam at .525 lift. Only a .035 margin to bind! So they're history and the search continues for a suitable, affordable replacement.
the LT4 spring bind spec is 1.22. Not good if installed at factory height of 1.78 and running a Hot Cam at .525 lift. Only a .035 margin to bind! So they're history and the search continues for a suitable, affordable replacement.
Melting Slicks
Joined: Jan 2000
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From: NW Chicago Suburbs
Here's the lowest cost LT1 aluminum head compatiable springs I am aware of (with no machining required):
http://www.jegs.com/cgi-bin/ncommerc...26&prmenbr=361
Chevy LT-1, 92-99 w/Aluminum Head
270-10308-1 Spring & Retainer Kit $147.99
The Crane part number is 10308
http://www.jegs.com/cgi-bin/ncommerc...26&prmenbr=361
Chevy LT-1, 92-99 w/Aluminum Head
270-10308-1 Spring & Retainer Kit $147.99
The Crane part number is 10308
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by silver & red CE
Here's the lowest cost LT1 aluminum head compatiable springs I am aware of (with no machining required):
Chevy LT-1, 92-99 w/Aluminum Head
270-10308-1 Spring & Retainer Kit $147.99
The Crane part number is 10308
Chevy LT-1, 92-99 w/Aluminum Head
270-10308-1 Spring & Retainer Kit $147.99
The Crane part number is 10308
Melting Slicks
Joined: Jan 2000
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From: NW Chicago Suburbs
I'd get the beehive ovates w/steel retainers, cost ~$70 over the Crane 10308 kit. I like damperless single springs because there's no heating (ie HP loss) from the friction. Since we're running cams like the HOT/CC305, we don't really need dual or dampered springs. If possible, single damper-less are always the best route.
The Ti retainers are not required, esp with HOT/CC305 cams, I just got 'em 'cause it's my Vette (and it's a $120 insurance policy)
The Ti retainers are not required, esp with HOT/CC305 cams, I just got 'em 'cause it's my Vette (and it's a $120 insurance policy)
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by silver & red CE
I'd get the beehive ovates w/steel retainers, cost ~$70 over the Crane 10308 kit. I like damperless single springs because there's no heating (ie HP loss) from the friction. Since we're running cams like the HOT/CC305, we don't really need dual or dampered springs. If possible, single damper-less are always the best route.
The Ti retainers are not required, esp with HOT/CC305 cams, I just got 'em 'cause it's my Vette (and it's a $120 insurance policy)
The Ti retainers are not required, esp with HOT/CC305 cams, I just got 'em 'cause it's my Vette (and it's a $120 insurance policy)
