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04-21-2002, 12:10 PM
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#1 | | Supreme Member
Join Date: Apr 2001 Location: Lebanon, OH
Posts: 1,224
Car: 91 Camaro RS Engine: Vortec LO3 Transmission: A4 Axle/Gears: 3.42 | LT1 valve springs on L31 vortec heads
A buddy of mine has a set of stock LT1 springs with basically no miles on them and he said he'd give them to me. If I put those on vortec heads, would I be able to run the LT1 cam with 1.6 rockers with no milling on the heads or anything? Just tryin to get that lift up as much as I can...
Thanks! | | |
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91 RS LS6/T56 - May run one day
05 Pontiac GTO LS2/T56 - Mostly stock |  
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04-21-2002, 04:09 PM
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#2 | | Senior Member
Join Date: Jul 2000 Location: Ga
Posts: 1,853
Car: 91 RS Engine: 305 Transmission: T5 Axle/Gears: 3.73 | You will still need to check the retainer to seal clearance no matter what springs you run. | |
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04-22-2002, 01:14 AM
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#3 | | Senior Member
Join Date: Jun 2001 Location: Pearland, Texas
Posts: 609
| Don't hold me to it but I think Vortec heads need special valvesprings. I think I read it in Car Craft, but like I said not 100% sure. | |
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04-22-2002, 04:37 PM
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#4 | | Senior Member
Join Date: Sep 1999 Location: Ewing, NJ
Posts: 2,142
| i have heard that teh L31 head has a very small spring perch on it, which leads to teh need for machining to use larger springs. one thing you can do within hte existing spring is to shim it a little. by preloading the spring a little more you are making it a firmer spring without have to change spring diameter. it will effect teh bind height of the spring a little, but it doesn't soudn to me that the kinds of lift you are going to be seing will be any problem.
later
tim | |
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04-22-2002, 10:47 PM
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#5 | | Supreme Member
Join Date: Apr 2001 Location: USA
Posts: 4,945
Car: yy wife, crazy. Engine: 350, Vortecs, 650DP Transmission: TH-350 Axle/Gears: 8.5", 3.42 | I've read that the Vortec heads have very large diameter guide bosses. You have to watch what the ID of the springs are, as well as the OD. IIRC, the OD is 1.25" like every other stock valve spring. But I could be wrong on that.
I can hunt through my pile of CHP mags and get back to you. They list the correct springs that Comp Cams makes for the Vortecs.
AJ | |
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04-23-2002, 01:07 PM
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#6 | | Senior Member
Join Date: Jul 2000 Location: Ga
Posts: 1,853
Car: 91 RS Engine: 305 Transmission: T5 Axle/Gears: 3.73 | The cheap a$$ K-Motions are what I used ................no prob | |
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04-23-2002, 01:08 PM
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#7 | | Senior Member
Join Date: Jul 2000 Location: Ga
Posts: 1,853
Car: 91 RS Engine: 305 Transmission: T5 Axle/Gears: 3.73 | The cheap a$$ K-Motions are what I used no problem | |
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04-23-2002, 01:44 PM
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#8 | | Senior Member
Join Date: Jun 2001 Location: 600 yds out
Posts: 1,520
Car: Bee-Bowdy Engine: blowd tree-fity Transmission: sebin hunnerd Axle/Gears: fo-tins | A stock diameter valve spring for the L05 heads are 1.250". I think the L31 Vortec used .980" springs if I remember right. | |
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04-23-2002, 04:20 PM
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#9 | | Supreme Member
Join Date: Apr 2001 Location: Lebanon, OH
Posts: 1,224
Car: 91 Camaro RS Engine: Vortec LO3 Transmission: A4 Axle/Gears: 3.42 | I cant find any info on what diamter the springs are, which is my problem. Heres what scriggins dickey wrote:
Chuck
Where we sometimes see a problem when using 1.6 rockers is in the guide area of the head where the puchrods travel. You may have to clearance this area to avoid any contact.
Nathan Grassie
DM91RS, you just changed the springs (and only) and the 1.6 rockers run fine with the cam? Is it the LT4 cam or the LT4 hot cam?
Thanks  | |
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04-24-2002, 05:00 PM
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#10 | | Senior Member
Join Date: Jul 2000 Location: Ga
Posts: 1,853
Car: 91 RS Engine: 305 Transmission: T5 Axle/Gears: 3.73 | Quote: Originally posted by Chuck!
I cant find any info on what diamter the springs are, which is my problem. Heres what scriggins dickey wrote:
Chuck
Where we sometimes see a problem when using 1.6 rockers is in the guide area of the head where the puchrods travel. You may have to clearance this area to avoid any contact.
Nathan Grassie
DM91RS, you just changed the springs (and only) and the 1.6 rockers run fine with the cam? Is it the LT4 cam or the LT4 hot cam?
Thanks | Chuck the springs are standard 1.250 diameter.
SDPC is correct...I had to clearance the pushrod holes for more clearance closer to the rocker stud.
I changed the springs, added .060 shims under the springs and used .050 Crane offset retainers to give a total of around .510-.515 total lift (retainer to seal).
I am running the stock LT4 cam with the 1.6 rollers for a total of .480 lift
Yes everything runs fine....still tuning. WOT is much better than the LO3 heads with the LT4 cam and stock 1.5 rockers.
See Ya
Last edited by DM91RS; 10-07-2006 at 05:43 AM.
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04-24-2002, 05:00 PM
| | ThirdGen 1992 Camaro
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| Tags | 980, bind, comp, compression, diameter, head, height, l31, lt1, rocker, spring, springs, stock, valve, vortec  | | Thread Tools | Search this Thread | | | |
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