How much lift can l98 springs take?
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Joined: Jul 2001
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From: Evansville, IN USA
Car: '89 GMC Pickup
Engine: 383 SBC Stealth Ram
Transmission: 700R4/VIG 3200
I was at the limit with a SLP 51006 .495/.502 lift camshaft so I changed them. Coil bind wasn't as close, but pretty close, as the valve seal were. Didn't run it that was so I couldn't say if it would have worked or not.
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From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
They are the same garbage you had before. I hope you didn't pay money for them.
Anything more aggressive than a worn-out stock cam with rubber rocker arms is too much for them. So I'd say about .425" is as far as you'd want to push it with a stock profile, somewhat less than .400" with an aftermarket grind.
Anything more aggressive than a worn-out stock cam with rubber rocker arms is too much for them. So I'd say about .425" is as far as you'd want to push it with a stock profile, somewhat less than .400" with an aftermarket grind.
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From: Philly, PA
Stock springs can take about .500" lift without binding but that's not the full story. They don't have enough pressure to control a hotter-than-stock cam. Also, you will smack the retainers against the guide seals long before you coil bind the springs (about .470" on most stock heads). While a fresh set of springs is better than ages-old OEM springs, it's not what you want if you have installed a performance (non-stock) cam.
I've disassembled about a bezillion sets of stock heads and they almost ALL have the same springs- 65 lbs. seat presure at an installed height of about 1.75". L-98, TBI 305, emissions-era V8s, etc, etc. You name it. That's what the vast majority of them got, with rare exceptions. For even a modest performance hydraulic cam you want something on the order of ~100 lbs seat pressure to keep the valves well controlled at higher RPMs.
I've disassembled about a bezillion sets of stock heads and they almost ALL have the same springs- 65 lbs. seat presure at an installed height of about 1.75". L-98, TBI 305, emissions-era V8s, etc, etc. You name it. That's what the vast majority of them got, with rare exceptions. For even a modest performance hydraulic cam you want something on the order of ~100 lbs seat pressure to keep the valves well controlled at higher RPMs.
Last edited by Damon; Sep 22, 2002 at 03:00 PM.
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From: Barboursville, WV
I was maybe planning a lt1 cam before I get new heads but Im not sure yet. Could those springs take the lift of a lt1 cam? I also plan on a set of world S/R torquer heads which can take a .560 lift. While i was doing the seals i just wanted to get some new springs in there. I paid 20 bucks for the set...
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Joined: Nov 2001
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From: Cleveland, OH
Car: '87 Camaro LT
Engine: 355 L98
Transmission: T56
keep in mind you'll need to get your valve guides milled and get screwed in studs put in if you go with a higher lift cam, might not need to with a stock lt1 cam but i'm not sure on its specs
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