zz502 upgrades
Race Director
Joined: Jan 2000
Posts: 13,014
Likes: 2,257
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Well, I'd still go for a cam....it's not that hard and will make much more of a difference on that motor than an intake or carb will.
The cam in the ZZ502 leaves a lot to be desired. If you still decide to run it, I'd throw 1.8 roller rockers on it.
The heads can make decent power especially with some work.
Either way, some real valvesprings will help even the stock setup.
I'd most likely trade the vacuum sec carb for a double pumper. I'd look at a 950HP or a 1000HP. They work great on the street on the big inch motors.
The intake is basically an Edelbrock Performer...an Air Gap would do better if your hood will clear.
You already have some 2" headers and a freeflowing exhaust right?
Still consider a real cam..you will absolutely love the difference!
JIM
The cam in the ZZ502 leaves a lot to be desired. If you still decide to run it, I'd throw 1.8 roller rockers on it.
The heads can make decent power especially with some work.
Either way, some real valvesprings will help even the stock setup.
I'd most likely trade the vacuum sec carb for a double pumper. I'd look at a 950HP or a 1000HP. They work great on the street on the big inch motors.
The intake is basically an Edelbrock Performer...an Air Gap would do better if your hood will clear.
You already have some 2" headers and a freeflowing exhaust right?
Still consider a real cam..you will absolutely love the difference!
JIM
Drifting
Joined: Oct 2003
Posts: 1,486
Likes: 10
From: Big Pine Key FL
I've been looking at valvetrain upgrades for my Ramjet (zz502) as well.
I've got a set of 1320-16 1.7 pro magnum rockers... talking to comp cams they reccomended 26120 beehive springs with 795 retainers. For a cam they reccomended 01-421-8.
Thoughts ?
I've got a set of 1320-16 1.7 pro magnum rockers... talking to comp cams they reccomended 26120 beehive springs with 795 retainers. For a cam they reccomended 01-421-8.
Thoughts ?
Race Director
Joined: Jan 2000
Posts: 13,014
Likes: 2,257
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Without me going and looking it up..what are the specs on that cam?
JIM
JIM
Race Director
Joined: Jan 2003
Posts: 15,175
Likes: 86
From: State of Confusion
Originally Posted by 427Hotrod
Without me going and looking it up..what are the specs on that cam?
#12366543 hydraulic-roller
LIFT: .527" I, .544" E
Duration at .050": 224* I, .234* E
I wouldn't have thought that .224*/.234* @ .050" lift would be enough duration to turn 6500 RPM in a 500+ inch Rat, but I'm not familair with them, either.
Racer
Joined: Aug 2001
Posts: 445
Likes: 2
From: Austin Texas
Originally Posted by Glensgages
..... according to the GMPP catalog:
#12366543 hydraulic-roller
LIFT: .527" I, .544" E
Duration at .050": 224* I, .234* E
I wouldn't have thought that .224*/.234* @ .050" lift would be enough duration to turn 6500 RPM in a 500+ inch Rat, but I'm not familair with them, either.
#12366543 hydraulic-roller
LIFT: .527" I, .544" E
Duration at .050": 224* I, .234* E
I wouldn't have thought that .224*/.234* @ .050" lift would be enough duration to turn 6500 RPM in a 500+ inch Rat, but I'm not familair with them, either.
Looking up the 01-421-8 that was referenced above, those specs are .521 Intake / .540 exhaust and duration of 236 / 242. Obviously, that is not much larger than stock. Comp recommended that one to me as well citing improved ramp up on the cam, etc, but it just didn't seem to be enough.
I ended up with going with a larger comp cams offering due to '427 Hotrod' advocating a similar spec'd cam and one of comp cams technical guys was running this cam in his 496 ci motor with good results.
The specs are - .622 intake / .617 exhaust with duration of 242 / 248. I can tell you that I have no problem with my power brakes and the car idles so well my wife can't even tell I put in a performance cam. Big cubic inch motors do love more cam. On top of that, it pulls like a train now.
Have fun with it and go with the larger cam.
Bryan
Last edited by 300ZXTwinTurbo; Oct 5, 2005 at 11:32 AM.
