CanadianZ

I have a couple of questions about my 94 Z28 and possibly doing a cam. I blew a head gasket and when the motor was out of the car I asked the mechanic to check the bottom end. Turns out the crank and caps were scratched. (I maybe be describing this wrong but was shown the visible wear)

Anyways, the motor is going to a machine shop to fix it. I am considering putting a new cam in it at this point because the motor is out, it’s getting torn apart and why put it back stock. I do have a couple of questions though.

I was considering the Comp 503 cam. Not too much lope still streetable and I don’t have to rev the **** out of it.

1. If I do just the cam and springs to support the higher lift will I see a power gain? (No 1.6rr)

2. With stock unported heads are 1.6 an value at all as flow on stock heads is the same at .500 and .600 lift from what I can gather.

3. My supporting mods are CAI and cat back 2OTL. No headers and I kinda don’t want headers to keep the car at least marginally quieter for the neighbours.

4. I would be willing to do 4.10’s. Necessary?

5. Reprogram for sure if I get the cam but I’ve been told that if I get a reprogram of the PCMw on the stock car (with CAI and Cat back) I could
gaim a bunch of power. I’ve never thought this to be true.

I guess the real question is am I going to see gains on a mostly stock car with that cam or am I just changing the sound? If the gains are minimal I might just leave it stock and do gears for a bit lire ‘pep’


thanks for any advice anyone can give. I very much appreciate it.

CanadianZ

Chimera96

yes you will see HP gain from the 503 with stock heads, certainly more using ported heads. You will need the pcm tuned accordingly for the cam. If you chose not to do the cam you will still gain HP just with a PCM tune. Typically you swap to a 160 degree thermostat so the tuner can then lower your fan on temps so motor runs cooler so he can add more timing and also you would need to use 103 octane unless you tell tuner you want to run lower octane. The higher octane tune would have a little more power

4:10's are a great gear for a T56 car and will really wake up the acceleration. 3:73 if a auto as 4:10's you will have high rpm's on the highway if you have a auto

1:6 RR are always a nice addition to a stock motor or one with cam. IMHO I would go NSA and run guide plates. You will need chromoly PR though if you use guide plates

DrewHMS97SS

A cam change will typically require push rod change anyways right?

Chimera96

IMHO even if the stock PR (7.200) are the right length (so they would work)….the higher rev ability with a bigger cam, likely increased spring pressure form the new valve springs required, the stock PR will "flex/wobble" some especially during high RPM use. Using a 5/16" with .080 thick wall chromoly PR would be better.

If going NSA RR I would also buy 7/16" vs 3/8" and then buy 7/16 ARP RR studs

My $.02 is if going cam and 1:6 RR go guide plates (ISKY adjustables) which require chromoly (hardened) PR so for that reason alone you would need to replace stock PR

for just a cam swap using stock heads on a stock block the 7.200" length is likely good but always best to measure for correct PR length

Injuneer