TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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I'm getting ready to order this cam and also some Comp 981 valve springs from Summit but I want confirmation this will work with the stock heads on an LB9?
I've heard the stock LB9 heads can handle a .500 lift max but can't I fudge a little and make the .510 lift of the ZZ4 can work?
BTW, is that lift for the stock 1:5 rockers or 1:6 rockers? I plan on running my stock rockers unless I really need to upgrade or if it's really worth it, if 1:6 will even work with the ZZ4. OR maybe only a 1:6 on the intake or exhaust? I just dunno. What type rocker arms do I have? I'm on a serious budget for this one.
Thanks!
__________________ www.TheFoat.com/92GTA1992 Trans Am GTA SLP: GMPP optioned "SLP Performance Parts Package" GTA, 220K Miles, Dark Jade Gray Metallic, LB9, 4L60, T-Tops, and Gray Leather. Documentation includes Window Sticker, Factory Invoice, Etc.
i'am not positive but, it should work. that lift is close to the limits of those springs. the lift #s should be with 1.5 rockers, and thats more than enough. that LB9 will sound mean with that cam. good luck.
I'm getting ready to order this cam and also some Comp 981 valve springs from Summit but I want confirmation this will work with the stock heads on an LB9?
I've heard the stock LB9 heads can handle a .500 lift max but can't I fudge a little and make the .510 lift of the ZZ4 can work?
BTW, is that lift for the stock 1:5 rockers or 1:6 rockers? I plan on running my stock rockers unless I really need to upgrade or if it's really worth it, if 1:6 will even work with the ZZ4. OR maybe only a 1:6 on the intake or exhaust? I just dunno. What type rocker arms do I have? I'm on a serious budget for this one.
Thanks!
i think .510 is a bit much for stock heads. i thought .480-.490 was about the max.
I'm going to have the engine out on a stand because I'm rebuilding it and porting the crap out of all the parts I have so assembling it and then checking the piston-to-valve clearance isn't a big issue. I'll go ahead and stick with the stock 1:5 rockers then. I just wanted to make sure it wasn't a for sure "no". I guess I'll post my results in a few weeks when I'm done with the build.
I ran the ZZ4 cam on my L98 stock heads with no problems.. 1.5 exhaust rockers 1.6 intake rockers. I did have screw in studs and guideplates, as well as the pushrod holes were machined bigger for the 1.6 ratio but I didnt have to mill the guides down.
I have that cam in my stock 083 heads ( you have the 081's) . I used SD1007 springs for it and they worked well with it . SD1007 springs ( scoggin dicky's) 1.25 " diameter 120 lbs@ 1.8" installed height and 350 lbs @ 1.2"
__________________ PROJECT UGLY DUCKLING
1989 10:1 353 L98Edlebrock base and runners ( really ported)ZZ4cam ,1 3/4 SLP shorties 083 heads ...cleaned up andstuded w/1.52 rr , LT4 valve springs and retainers and a 3 angle valve job
suspension mods (Hotchkis LCA's PH bar, KYB shocks and struts)
T-5 3.73
T-62 turbo to be installed next ...Exhaust clip ...gota let it load.... http://media.putfile.com/My-exhaust-clip
I'm taking the advice on new retainers but DAMN! I can only find 1 set on Summit that matches the outside diameter of the Comp 981's which is 1.254", and it's the Edelbrocks @ $55.39!!!!! That's only like $2 less than what I'm paying for the springs!
The stock retainers beat up the valve seals at around .460 lift. If you get shorter valve seals you can run the stock retainers. I've had a few people tell me about the issue with the seals, you should ask them how they remedied it.
"I'm getting ready to order this cam and also some Comp 981 valve springs from Summit but I want confirmation this will work with the stock heads on an LB9?"
Have a look on eBay first.
New crate motor takeout ZZ4 cams FS all the time for $125, often less from private sellers.Summit price $205
The correct ZZ4 springs (#12551483 ) are cheap from GM if you buy the set of 16 , not individually
I bought my ZZ4 cam as a take out with about 200 miles on it. Paid $75. Had the heads cleaned up, valve job done, and new springs, retainers, seals, yada yada yada all done for about $150 for both heads.
Ive had a post going on using a ZZ9 cam I picked up for real cheap. I may have issues w/ using it. Id be using it on an 87 TPI w/ stock heads. Like 92GTA Im on a budget w/ doing a cam swap. Would using a ZZ4 be a better option?
