My new long block arrived today. It was admittedly creepy when I giggled and danced like a little girl as the truck driver lowered the lift gate, but once we got beyond that, I had to start thinking about some of the upgrades I have planned prior to install One of the being my cam and valve train.

For the cam, I have contacted Comp Cams and they suggested their part number 01-424-8. I want some iopinions from some of the pros on this site...is this a good cam for a primarily street driven car that will see ocasional strip duty and possible a run or two at the Silver State Classic?

This cam has 294/300 advertised duration with 242/248 at .050.
The lift of the cam is 540/560 and it has a 110 lobe separation. The rpm
range is from 2500 to around 6000 rpm.

VEHICLE INFORMATION
Make:Chevy Model:Camaro Year:1968
Vehicle Weight:3200+ Axle Ratio:3:55
Transmission Type:MAnual 4 speed, soon to be a TKO-600 or T-56
Tire Height:26
Engine Block Type:GMPP ZZ502
Bore:4.47Stroke:4.00 Compression Ratio:9.6:1
Piston Type:Forge Aluminum Connecting Rod Type:Forged Steel Shot Peened
Intake Manifold Type:Edelbrock Airgap RPM
Cylinder Head(s) Year: GMPP Aluminum oval port 110cc
chamber Head Part Number:12363390
Head Runner Volume:290cc Intake; 110cc Exhaust
Ported Heads:no
Intake Valve Size:2.25Exhaust Valve Size:
Rocker Arm Type:RollerTipRocker Arm Ratio:1.7
Exhaust Header(s):1.75 or 2"
Exhaust Pipe Size:3 inch
RPM Range:800 to 6000
Nitrous Oxide:No
FUEL DELIVERY
Fuel Type:unleaded Fuel Octane Rating:91
Carburetor:Edelbrock Perfmormer
Carburetor Size:825cfm
Air Filter:K&N
How Will This Engine Be Used?
Performance Street
Additional Comments:
I'm interested in a complete hydraulic roller cam
package (Cam, rockers, beehive springs). Just want to wake this engine
up a little and get it closer to 600HP without negative impact to street
manners. It's an all new ZZ502 long block PN 12371204. Manual trans will
be upgraded to a TKO-600 in the future. Current trans is a Muncie 4
speed. I want the cam to match the TKO (if that's possible). Car will be
driven mostly on the street but is being set up for pro-touring, will
see occasional 1/4 mile duty and possibly some open road racing at the
Nevada Silver State Classic.

Let me know what you think.
Tim

Dont go with anything less then 250 duration, and it will make good power,
dur. in the 240s will cost you some power. Also go with as much lift as you can, over 600 would be good. I'd also recommend using someone else beside Comp, their cams float the valves sooner. I run a Lunati with Crane lifters, revs to 6800 no prob.
2"-2 1/8" headers, 3" exhaust is small...
I'd run a good single plane intake with a stick and ovalports... And get rid of that carb, an HP950-HP1000 would make way more power. Dont forget the fuel system...

Hello, 67RS502,
I've been studying on these GMPP crate engines and how they respond to different bolt ons. Most of what I found was on the ZZ454, which uses the same GMPP oval port aluminum heads but is different in a few other obvious ways (bore, stoke, little less cam, little less compression), but I think the result would likely be the same with a ZZ502.

In Sept 04 HOT ROD, they used a slightly more mild Comp Cam than the one I am asking about, along with the Comp Cam beehive springs on a ZZ454. They were able to take the engine up to 6600RPM before they "gave up" and they had no valve float. With the stock springs and cam, the valves started to show float at 5800RPM. I'll be going with the beehives regardless of Cam selection.

I plan on checking with a few other cam manufacturers before making a decision (Lunati, Isky, Crane, Edelbrock).

I'll run the Edlebrock Performer 825CFM until I can afford to bump up to EFI (I kinda like the looks of that new Barry Grant Big Block Six Shooter too). I know it's not the best carb, but it's farely new and has seen about 50 miles of duty on my 396 with no major complaints.

In Oct 04 HOT ROD, they had a Hooker long tube header shoot out on the same ZZ454. The 2" headers and 1 7/8" headers produced both higher peak and higher average TQ and HP than 2 1/8". The 1 3/4" headers ran pretty much neck n' neck with 2 1/8". It was pretty amazing. The overall delta in power and torque only varied a few TQ and HP between each tube diameter and about 10 HP and TQ from the top of the field to the bottom. At the suggestion of a friend, I might go with shorties into 3" pipes just to avoid all the clearance issues, and then make my power elsewhere.

In July 04 HOT ROD, they ran an intake comparo on the ZZ454. They compared the Torker II 2-0, Performer 2-0, Victor Jr., Performer RPM, and Performer RPM Airgap head to head. The RPM Airgap won out in both average power and torque over the Victor Jr. At peak power, the Victor Jr only made 3HP more than the Airgap and the Airgap made up for that by producing 22 ftlb of TQ more than the Victor Jr. Based on that result, I'm going with the airgap on this ZZ502.

They also took a ZZ572/620 and replaced the factory single plane with the RPM Airgap 2-R. The result was a gain of lb ft of TQ and only a loss of 14HP at peak. All that TQ makes up for the slight loss of HP and then some. I'm sold.

Regards,
Tim

p.s. Anyone have a Desktop Dyno they can run the cam and engine combo I listed across to tell me what kind of power I'll be making?

Appreciate it!!!!
Tim

They also took a ZZ572/620 and replaced the factory single plane with the RPM Airgap 2-R. The result was a gain of lb ft of TQ and only a loss of 14HP at peak. All that TQ makes up for the slight loss of HP and then some. I'm sold.


I noticed a missing number in the above. The 572 made and additional 65 lb ft of TQ with the RPM Airgap 2-R. Dunno what happened in that previous post....

Nothing creepy about your reaction when seeing the 502, I caressed my new 502 like it was my mistress. Is that odd? Maybe I shouldn’t have typed that. BTW, a mistress would have been cheaper, but less fun!

I have decided to drive my 502 until "bored" and then get a supercharger! Why try and squeeze 50-100 HP more when you can boost it 50% more!!!

Seriously, my worry is that my M20 will begin to cry for mercy so the next move I make is a TKO 600.

Nothing creepy about your reaction when seeing the 502, I caressed my new 502 like it was my mistress. Is that odd? Maybe I shouldn’t have typed that. BTW, a mistress would have been cheaper, but less fun!

I have decided to drive my 502 until "bored" and then get a supercharger! Why try and squeeze 50-100 HP more when you can boost it 50% more!!!

Seriously, my worry is that my M20 will begin to cry for mercy so the next move I make is a TKO 600.

LOL
(:-D
Glad I'm in good company.

Good point on the supercharger thing. That was something I had been giving thought to, too. I mean...by the time I get all I want for this cam and valve train upgrade package, I will have spent almost half of what I'd need for the huffer.

My rear diff will drop it's guts before my ol' Muncie. Both are long in tooth, but the rearend is definitely on it's last leg. It's the next item up for replacement after I get this engine in.

Tim

There's just nothing like peeking under the hood and finding a ZZ502 sitting between the wheels. OK, I'll admit that I'm getting jealous now....Sounds like you're going to have a sweet setup. Congrats on the new arrival!!!!

PS - I'd be a dancin' fool too if one of those showed up at my door, hehehehe, sure hope Chip Foose is reading this...hint..hint

I think you should follow Comp Cams Recommendations, they are the real experts. Your combination sounds very good for a street/ occasional strip car. I agree you could use a better carb, meaning bigger, your 3" exhaust is right on for what you're doing. 2"-2 1/8 headers are perfect, I would lean toward the 2" headers. Most defnitely keep your lift under 700, for a street driven car, why beat your valve springs/valvetrain to death. To be perfectly honest, do you think you will be twisting your motor past 6500? Another surprise to more Horsepower and Torque below 6500, use a Oval port intake that's gasket matched with plenum work, you will be very happy.

John

I think you should follow Comp Cams Recommendations, they are the real experts.

John
Dont know about all that;)

Tim,
Check out the ZZ-572 cam at GM, was told it was a direct swap with everthing your looking for. I'd up the gears to 4:10 or 4:56 and realy start having some fun with the "Fast and Furious" import freaks! I can tell you one thing, your going to love the power it puts out in its crate form!!!!! I'd just play with it awhile before I'd swap cams.According to my wheel dyno sheet with a few jetting problems, bouncing square 19.50 Mickey Thompsons and a few other problems, I managed to get 390 hp to the rollers on the dyno. Weve made alot of improvements since then and are going back to the dyno soon! As far as the Hp/torque spec sheet that comes with the ZZ-502, its very,very close. Horsepower drops like a rock after 6000 rpm. All in the stock cam set up. Heres my set up:
'67 Camaro RS/SS, Back halfed and monster tubbed.
ZZ-502, Team-G W/950 Holley HP
Hooker 2" headers
Complete MSD ingition with a 6AL box
TH-400, 3500 stall, full manual
5:13's and a 2900lb street car=FUN!!!!!!!!!!!!!!!!!!!!!!!

Thanks, Catrancher.

I did decide to install the ZZ502 as is. Just bolting on an Airgap RPM, Edelbrock water pump, ministarter, McLeod Bellhousing, Centerforce flywheel, 12" clutch and a Miloden oil pan and dropping her in. Check out a few of my recent posts in the Engine forum and see if you have any answers for those.

Appreciate it!
Tim

I bet true 1-7/8" four tube, long headers should just about work great on a 502 v/s 1-3/4" ones on a 454.

As always, jmho.

pdq67

I went with 2" Hooker Comps.

GMPP recommends 2.25" primaries in the installation manual, but HOT ROD showed the 2" to be the best for the Z454 and I assume the ZZ502....in their Every Trick in the Book sereis last year.

Tim