First off, I wanted to say thanks to all of the guys who have helped me out over the years. You made my work much easier and more efficient.

The specs on my car are now:
350 sbc low compression pistons
stock qjet carb rebuilt and running good before recent upgrades
vortec 64cc heads mild port and polish professional valve grind and springs and retainers to match cam
comp xe262h cam (full cam package with all necessary matching components)
1.52 ratio full roller rockers
edelbrock performer intake
plenty of suspension upgrades not relevant to this thread

If you need any more relevant info on the car, let me know and i can tell you.

The car has recently developed a choppy as heck idle. this was immediately following the cam, heads, roller rockers etc install. The car moves like crazy off idle with great throttle response. I set idle at 500 rpm and ignition timing at 8* advance. I attempted to degree the cam, but i didn't have the extension for the dial indicator so i held an old lifter on top of the new lifter to compensate. The cam was degreed almost perfectly. The cam manufacturer said that the idle would be "noticeable" but what i have is ridiculous. It seems like i'm going to stall at stop signs because the idle is so rough. I checked plug wires and found a few cracked and replaced them. I checked and adjusted the carb (set dwell, idle speed, and choke). I checked compression on a few cylinders, the plugs are a b*tch to remove because of the headers and the compression gauge is even harder to get in. I will check the rest of the cylinders when i get time.

My thoughts are that i adjusted the valve lash incorrectly, but once again because of the setup, the valve covers are a PITA to remove. I was just hoping some of you guys might give me some other options of things to check. At the very least, i was hoping you guys could tell me if I'm on the right path or if my cam is performing as it should and i'm just being paranoid.
Sorry about the long post and thanks in advance for any help.

 

i copy and pasted this....I suspect your rockers are improperly adjusted. There is a very simple method to adjust rockers that doesn't require precise knowledge of engine position:
1) Loosen all of the rocker arms.
2) Bring the engine to the TDC mark (doesn't matter if it's on #1 or #6 firing position).
3) Take the slack out of all of the rockers (just take out the slack, nothing more at this point).
4) Rotate the crankshaft 1/2 turn.
5) Take the slack out of any loose rockers (should be 12 of them loose, but check them all).
6) Rotate the crankshaft another 1/2 turn in the same direction (back to TDC).
7) Take the slack out of any loose rockers (should be 8 of them loose, but check them all).
8) Rotate the crankshaft another 1/2 turn in the same direction.
9) Take the slack out of any loose rockers (getting the picture yet? There should be 4 loose, but check them all).
10) Give each rocker one additional full turn down.
11) You're done.

Note: This only works with hydraulic lifters.

Pulling the #1 spark plug and watching for compression as the crank approaches TDC is the "best" way to determine #1 firing position. You can be fooled looking at the rockers.

 

Thanks, I will definitely check that out this weekend.

 

Or while the engine is running loosen each rocker arm until it chatters and then tighten until the sound goes away. Then tighten another half turn.

 

Also 500 is a relatively low idle. Bring it up to 750-1000 and see how rough it is there. How much vaccum are you pulling? A sloppy reading back and forth between 10-15 for example can prove improperly adjusted valves or other problems.

 

I will check the vacuum this weekend as well. As for the idle, i did move it up to 750rpm in drive, but when i put it in park the idle shot up to 1200 and the car dieseled when i turned it off.
I thought about adjusting the valves with the engine running but i just put that valvoline racing full synthetic high ZDDP oil in there at $9 a quart. I just can't bring myself to let that stuff spray all over the engine bay.

 

The engine dieseled because your timing was higher at 1200 RPMS. Rent a vaccum gauge at auto zone, you can check it on their parking lot.

 

M1tch, you're the man. I have a vacuum gauge, i just have to go to my sister's house to work on the car. I went there tonight to switch to the sunfire (that car's humiliating) until i get the camaro running right. Anyways, while i was there i quick threw my vac gauge on there and it was vibrating like crazing and moving between 15 and 13 in of Hg sometimes dipping as low as 12. So i guess that i will set the valve lash again and let you guys know if that fixs my problems. If not, what do you think i'm looking at? Bad intake gaskets? Problem with the cam?

 

here check this website http://www.secondchancegarage.com/public/186.cfm

It will help you diagnose whats exactly going on

 

That's exactly what i needed. It looks like a constantly leeking or burned valve or a poorly seated valve along with the high performance cam scenario. That just supports the theory of improperly adjusted rocker arms. Thanks for the help. I'll update after I readjust them.

Everyone else, check that link out. It definitely helps with the use and understanding the versitility of a vacuum gauge.

 

RazorN8-- I hope you cann get it worked out!!!

M1tch-- Thanks for puting in that link!!! Now we need to get those 2 tools!!!

......

 

,

I have the same cam in my 383 TPI, I did the IAC & minimum air rate procedure and set the idle at stock 500rpm and set the baseline timing at 10°. Then, reprogrammed the ECM base timing to match and also reprogrammed the ECM desired idle vs Temp table to a higher range to satisfy the cam.
I don't know how this is done for CCC.
I also had to upgrade to a heated O2 sensor due to the headers not letting it stay hot.

 

Ok, I redid the valve lash. I used this method instead of the method mentioned above. It turns out that I was about right on the first time I did it. I used half the preload this time though. I also leaned the mixture a little, moved the idle up to 850 rpm in park, found and fixed a big oil leak, and messed with the timing some more (ended up putting it back at 8* advanced though). I got the idle to smooth out a bit and the vacuum to move up to 17 in of Hg with a random tick down to 16 from time to time. The idle is still really rough at idle in gear though. Any thoughts? I want this to get just a little better. Thanks

 

Are you using the correct spark plugs? Make sure they are .708 length plugs. I recently found i've been using the wrong plugs and my car idled rough under 850 rpms as well. I had my idle at 1000-1100 and it idles in gear at 900. Your vaccum reading is good but again make sure you have the right plugs, if they're too short the electrode won't be close enough to the chamber causing loss of spark.

 

Ok, I'll check tomorrow. since you're still online and you run similar heads to me, can you suggest what plugs to buy if mine are wrong?
I'm pretty sure you're right. IIRC I'm running these which would cause my problem. If its not these, its another form of the old +4 rip-off. I guess changing them couldn't hurt either way.

 

Yea the reach is only 0.441 which I bet is whats causing your problem! Buy some Autolite AR103's and your problem will be fixed. Don't feel dumb I did the same thing, i havent got my car back yet but they changed my plugs and adjusted valves and changed rocker arms and some other good stuff so i cant wait to feel the difference! Not sure how it allowed me to still run high 13's but it did idle rough at lower rpms! If you dont like the Ar103s autozone has the other plugs that match it. Alot of people like the AcDelco plugs, my performance shop recommended NGKs

 

Yeah, i picked up a set of $3 NGKs. It smoothed out the idle and acceleration, but it didn't add much in the way of performance I dont think. Thanks for the help, I would have never guessed sparkplugs

 

Hm, i'm suprised it didn't help much on performance if it worked wonders for you idle and acceleration. So the problem is solved?

Were the plugs .708 reach?

 

Yeah, they were .708 in. The acceleration smoothed out, it didn't improve really. Definitly better than before though. More driveable.