Broken Valve Spring - Need advice
Thread Starter
Cruising
Joined: Feb 2010
Posts: 11
Likes: 0
Broken Valve Spring - Need advice
To make it worse, I bought the car and cannot locate the prev. owner to determine the cam. Am having to measure one of the good springs to check install height and psi, but I would like some advice on what replacement springs to use. Comp is expensive compared to PAC 1518's which I understand would be suitable on the LS1 that has been cammed.
Any thoughts would be deeply appreciated. I'm lucky that the old springs were dual springs and the valve didn't drop at least - but it's still an ugly situation.
Thanks all,
Bengt
Any thoughts would be deeply appreciated. I'm lucky that the old springs were dual springs and the valve didn't drop at least - but it's still an ugly situation.
Thanks all,
Bengt
Pro
Joined: Jan 2006
Posts: 541
Likes: 38
From: Temecula CA
The PAC 1518,s are the same as the PAC 1218, except they have been treated for longer life. They are good up to .650 lift cams, and are a direct drop in replacement for the stock LS1 spring. I just installed a set on my A&A supercharged LS1. Since you have dual springs now, you'll likely need new retainers as well, as I think the duals use a different retainer. There are numerous threads about these springs as well as the Comp Cams 918 springs. Do a search and you'll find plenty of info.
Phil
Phil
Thread Starter
Cruising
Joined: Feb 2010
Posts: 11
Likes: 0
The PAC 1518,s are the same as the PAC 1218, except they have been treated for longer life. They are good up to .650 lift cams, and are a direct drop in replacement for the stock LS1 spring. I just installed a set on my A&A supercharged LS1. Since you have dual springs now, you'll likely need new retainers as well, as I think the duals use a different retainer. There are numerous threads about these springs as well as the Comp Cams 918 springs. Do a search and you'll find plenty of info.
Phil
Phil
so making a mistake on ordering these would be a big problem. My wife is away on military training so this job is being done by my local mechanic who was going to buy the Comp's - and by dropping off something different, obviously I'm assuming alot of risk on the operation.Thanks again
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Duals to beehives will require springs, shims, retainers and seats unless you have the GM one piece seat/valve seals installed. Since the car has duals, the seals and seats are likely separate.
Thread Starter
Cruising
Joined: Feb 2010
Posts: 11
Likes: 0
Thanks for the help, appreciated.
On another note, any thoughts on a rear lowering kit to actually remove the lowering that was done?
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
Well I've changed my mind. I'm going to go with the Comp kit, despite the price (I doubt at the end of the day it will be much different anyhow) because realistically the dual spring, albeit heavier, saved that piston likely. Also, not driving it for the past 3 weeks has saved me the $300 difference anyhow in gas..
Thanks for the help, appreciated.
On another note, any thoughts on a rear lowering kit to actually remove the lowering that was done?
Thanks for the help, appreciated.
On another note, any thoughts on a rear lowering kit to actually remove the lowering that was done?
Thread Starter
Cruising
Joined: Feb 2010
Posts: 11
Likes: 0
Seems like so much info out there is simply opinion. I thought duals would be safer, since they did keep the valve out of the cylinder, but so many people recommend the PAC beehive single design.
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
I've now been warned away from dual springs. Have you heard of the inner spring snapping and actually torsioning the outer spring in some way as to break the main spring?
Seems like so much info out there is simply opinion. I thought duals would be safer, since they did keep the valve out of the cylinder, but so many people recommend the PAC beehive single design.
Seems like so much info out there is simply opinion. I thought duals would be safer, since they did keep the valve out of the cylinder, but so many people recommend the PAC beehive single design.
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Verdad Gallardo
Team Owner
Joined: May 2001
Posts: 87,367
Likes: 1,593
From: Western NY
Well I've changed my mind. I'm going to go with the Comp kit, despite the price (I doubt at the end of the day it will be much different anyhow) because realistically the dual spring, albeit heavier, saved that piston likely. Also, not driving it for the past 3 weeks has saved me the $300 difference anyhow in gas..
Thanks for the help, appreciated.
On another note, any thoughts on a rear lowering kit to actually remove the lowering that was done?
Thanks for the help, appreciated.
On another note, any thoughts on a rear lowering kit to actually remove the lowering that was done?
If so, the first thing to try is just cranking on the bolts that are currently in the car. Turning them clockwise (tightening) will raise the car. Just count the number of turns, and do it the same on both sides. Then drive the car a little bit and let it "settle". Then measure from the center of the inner a-arm pivot bolts to the ground, on both sides, and adjust as necessary, to get that dimension the same on both sides.
Former Vendor
Joined: Mar 2004
Posts: 1,518
Likes: 7
From: Valencia CA
OP...
Dual springs are the way to go.....they just saved your azz not to mention.
We have been shipping our LS heads with dual springs since 2004.
The Internet is great but there is also alot of bad info out there.....you need to really think about who your going to listen to.
PM me....our springs may drop right in your heads requiring nothing additional. Just need to know the step diameters of your retainers which you can measure with a caliper....worst case you need to buy the retainers as well....they aren't that expensive. Springs and retainers would be less than $450
I would put you into our upgrade 8019 springs....I don't know of a single failure with them and thats an impressive comment to make when you ship as many heads as we do. Its an outstanding spring and has slightly better valve control than Comp's 921 spring.
-Tony
Dual springs are the way to go.....they just saved your azz not to mention.
We have been shipping our LS heads with dual springs since 2004.
The Internet is great but there is also alot of bad info out there.....you need to really think about who your going to listen to.
PM me....our springs may drop right in your heads requiring nothing additional. Just need to know the step diameters of your retainers which you can measure with a caliper....worst case you need to buy the retainers as well....they aren't that expensive. Springs and retainers would be less than $450
I would put you into our upgrade 8019 springs....I don't know of a single failure with them and thats an impressive comment to make when you ship as many heads as we do. Its an outstanding spring and has slightly better valve control than Comp's 921 spring.
-Tony
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
with Tony. Why go to a single spring after what just happened? I can't believe a set of duals is that much in Canada. Isn't the exchange rate almost even now? About raising the rear end..... you only need to screw in the adjuster screws, it doesn't matter if they're aftermarket. Remember to leave about a 1/2" rake when you're done; it helps with high speed stability.
