I have an 87 5.0 TPI 700R4 3.40posi and have done all the normal mods ie: headers, 3" exhaust, gutted maf, 3" air intake, ported plenum, ect. I am running stock intake and heads and motor was rebuilt stock about 30K ago. I am not looking to change heads or intake on this motor or loose driveability but I really have to get a little more preformance out of it till I can do a 350, so I am considering a cam change or 1.6 rockers with stock cam. Have been looking into the crane compucam and comp cams but I am really confused as to what I should be looking for. The choice for an automatic trans and 5.0 aren't really that much over stock or am I wrong about this. What durations and lift would be good for a weekend driver without loosing too much in driveability or low end torque since I don't ever take the motor over 5500rpm or would I be better off as far as expense/time/performance gain in just running 1.6 lifters with the stock cam...thanks to all those that can help with this...by the way car has ADS chip(was in it when purchaced)

 

I would look for a cam with the intake duration at or below 210. Pick a dual pattern cam, which means the exhaust duration will be more, and stay at or below around 218. Try and get lift of about .450 Make sure the LSA is 112 or 114 so its friendly with your computer. That would be your best choice from what you are looking for.

 

Another tip, too. You want fast valve action so your cam choice should have fairly aggressive ramps.

Most of the big cam companies have specfic series that feature agressive ramps; like CompCams Xtreme Energy series.

Keep the duration on the short side, lobe lift high and lobe separation angle on the wide side (112/114 degrees.) Short, high and wide.

You'll be rewarded with better idle, higher vacuum (good for the brakes) and a nice power increase.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

[This message has been edited by JakeJr (edited January 31, 2001).]

 

thanks for all of your help...

 

I've also been trying to find a suitable cam for the same car. I spoke to Willie about this and he recomended the CompuCar cam
part number 104224.

Lift (1.5 rockers)----452/465
Lift (1.6 rockers)----482/496
Dur @ 50--------------214/220
LSA----------------------------112

What do you guys think of this cam in my motor? I rekon it should be good for over 40 bhp but how much torque will it give?

Thanks for the help

Rob


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1987 IROC-Z Auto (LB9)
Black/grey with the stance of a streetfighter

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat.

Future mods:
K&Ns
RAM Air
New Underdrive pulleys-either March performance pulleys or Auto Specialties Performance
Air foil

 

That's a pretty healthy cam for a 305.

I'm thinking that because of the 45 fewer cubes as compared to a 350, the bottom end will be somewhat soft.

Just my thoughts.

Jake



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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

The smaller of the 2 SLP cams works great in my friends LB9 motor, only mods being cat-back.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!

 

I say run a GM ZZ4 cam. It has short duration on the intake lots of exhaust duration and good lift. It has a 112 LS and will give a good vacuum signal. Specs are 208/221/112LS lift=.474/.510 w/1.5 rkrs. Check your valve springs though! This is a short duration high lift cam and will generate excelent torque. Look at the ZZ4 dyno sheet. the torque curve is broad and flat - a great street combo.

 

Don't bother with the ZZ4 unless you want to machine your heads. .510" on the exhaust is too much for the springs, plus the retainers will smack the valve guides on stockers.