This is my starting point, 1984 z28 originally had the high output motor now has a freshly rebuilt1980 350 (3970010) with only three passes, I believe it has the edelbrock rpm cam, edelbrock eps intake, edelbrock 1406 carb(600cfm), prw roller tip rockers, 14078261 heads I think, fiberglass hood, hardtop, 5 speed manual, 3.73 gears, 245/60/15 in the rear, This is about all I know about the car. Any estimate on power, weight, qtr mile times? Just curious what you guys think. Trying to figure out which way I want to go. 383 or build it for a weiand supercharger. I won't be able to take it to the track till next summer. Here's me driving it yesterday for the first time since I've owned it(few months). I kept missing 2nd and third lol, only was able to take it to about 3800-4000 rpms because I'm missing a hoodpin in the front.
Car was a blast to drive though, actually accelerated pretty quick

 

Less than 300hp. Is it firing on all cylinders? It sounds strange.

 

i agree something sounds off...

but running tip top high 13s but realistically like low to mid 14s.

 

I'll pull the plugs and make sure

 

I agree as well, this was my first test drive after getting everything running. Timing is pretty much spot on. I'll see if I can take another video. I'll check the spark plugs and wires when I get off. Oh yea it's also got headers and y pipe with 3 inch stainless steal exhaust back into a pypes violator muffler.

 

Just listening to it there is something wrong. Maybe the timing is out or its lean. What is the timing at?
Put a vacuum gauge on it and hold it at 2000 rpm. Is it smooth or bouncy?
But in the end you have a badly mismatched engine.
You have an edelborock performer rpm cam that goes to 6500 and was designed to work with performer rpm heads on a set of stock heads with an intake that goes to 5500 and a edelbrock carb that is tuned really lean from the factory and very often has a terrable bog.

 

Timing is pretty much spot on, isn't lean, I believe it's actually rich by the smell of the exhaust.

Any suggestions on heads? Intake? Carb? I'm not set on what I have, this is just how I got it. My "starting point".

 

Cam selection is going to depend on what you want the motor to do. Do you want it to be mild/street friendly. a bit more on the wild side/less street friendly, or race cam that isn't street friendly? You'll want to pick your heads based on the intake manifold and cam you choose. As far as carb, my only experience is with my edelbrock 600 #1405, and it has been a positive one, it was seriously as easy as buying it, putting it on, and turning 3 screws. I'd also pull all of your plugs and just double check that you don't have one cylinder acting up. It's surprisingly easy to run a v8 on 6 cylinders...(don't ask.)

 

What if I get better heads and port match them to the intake?

I like torque, pretty much where I'll be driving at on the street, I don't really want to have to wind up to 5000-6000 rpms to reach power.

Street friendly that I can take to the track every now and then. Reliable 350-400 horses and call it a day. I have the 1406 carb which isn't really too much different from the 1405, it was the easiest carb I ever had.

 

Right now power comes on at about 3400 rpms and doesn't really drop off up to about 4700, I haven't really taken it much further yet but I'll get a better video and actually pay attention to rpms and what I feel.

 

The 1406 is not the same as a 1405 due to the fact that it has different jets, metering rods and springs in it as it is designed to run leaner. If you called edelbrock they would tell you to use a 1405 for your setup. Your setup it is most likely running lean at part throttle, cruise and wot with that carb.
If it smells rich while cruising then you may have cylinders that are not firing or not fully firing causing the rich smell. Look at the plugs and make sure they all look the same and or do a compression test.

 

Port matching would give you a little bump up in power, you'll want a dual plane intake for torquey street use. Heads that flow about 200cfm to go with the intake manifold, depending on what octane gas you want to use, you'll want a different size combustion chamber (the 64cc heads on my 350 put it at about 10.5-11:1 and I have to use 92 octane). You'll also want to figure out what cam you're going to put in it so that you don't have too much lift for the head/springs to handle. What size rockers do you have? Is it a roller cam?

 

So what intake should I be looking at? I always use the 92 or 93 octane gas. As far as heads go which ones have the 64cc chambers? I know mine are 78cc's right? I have a spare cam sitting in the garage, I'll get the specs on it. I think it has a .5xx lift, not sure. I think it's a Herbert cam. The rockers I have now are prw 1.52 roller tip rockers and I think I have a hydraulic roller cam(not sure though) I completely guessed it was the rpm cam because everything else was edelbrock. This was all the previous owners doing. The carb I have I really like, it's very easy to work on and rebuild.

 

For some reason I'm running rich then. I get flames out the exhaust after I hit the gas hard and let off. Timing too far advanced? The pump shot is at it's lowest setting too! I know for a fact I'm running rich because I pulled the plugs and they all have black soot. These plugs are a few weeks old and this car has been driven once. Do I need a hotter plug? The plugs in there are champion rv17yc. I just put in a brand new coil. The cap and rotor look fine.

 

The intake you have on it currently will work fine, it's a dual plane. Your heads are more than likely low compression heads, I couldn't find much on the casting numbers, but they came from the early 80s, so they're probably smog heads. If you want to stay edelbrock, they make some pretty decent heads. I'm not sure if you want angled or straight plugs, but these are the 64cc heads with straight http://www.summitracing.com/parts/edl-60899/overview/ and here's angled http://www.summitracing.com/parts/edl-60999/overview/ . And as far as cams go, this one would be close to the one you want http://www.compcams.com/Company/CC/c...x?csid=85&sb=2 . Those are just the specs, and you don't HAVE to get a compcams camshaft, I just like the way their site is set-up.

Also, the T5 is only rated for 200 ft lbs, just fyi.

 

Hotter plugs might band-aid the problem, but you're still running rich. You might need to jet the carb.

 

Can you get video of it shooting flames? That looks badass!

 

No you should not need a hotter plug. You don't use a hotter plug because its running rich.
What is your fuel pressure at?
When you pull all the plugs do they look the same or do some look different?

With all that fuel in the exhaust I would check for a bad cylinder first. Do a compression test and post the results.
If compression checks out good double check tdc with a piston stop.

Post back the results

 

A power balance test would also work, and is a bit easier.

 

I'll check all those out, being that my compression is probably at 8.5 how much power will 10.5 net me?

Oh and I know about the t-5, in the near future a t-56 should be going in

 

Maybe I set the float too high when I rebuilt the carb? Are the plugs I'm running ok? Could be a timing issue? Too retarded or advanced? If this carb is naturally lean then I'm sure I could lean it out from where it's at now

 

Fuel pressure is generally at 5psi. It's pretty erratic because I use a mechanical pump. All the plugs are covered in black dry soot. I'll see if I can get my hands on a compression tester. What numbers should I be looking at cold? The headers I'm running make it impossible to do anything with the car warmed up.

 

Actually I do have a video lol, I'll post when I can

 

How do you do that?

 

Timing is probably okay, if it runs and runs smooth at idle, your timing is fine.

 

Don't have any idea what the numbers should be without compression ratio and cam specs. For now we are just looking for around the same number in all the cylinders. If one is a lot lower than the others then there is a problem.

Basically while the engine is idling pull a plug wire one at a time. It should idle worse. If you pull one and the idle doesn't change you have a dead cylinder or if the idle changes but not as much as the ones did then you have a partially dead cylinder.
Just be careful not to zap yourself!

You can also do it by poking the boost with an old school test light hooked up to ground, but then you will wind up with little holes in the boots.

and yes the plugs you are running should be fine.

 

 

I'll give this a shot

 

Lol, your reverse sounds like mine.

 

Haha! I don't know why but reverse always fights me! Either I have to slam it or ease it in

 

Try going to second or fifth and then reverse, that usually works for me.

 

how sure are you that the timing isnt off? smell is not always right, by the way the car started it sure sounds like it is off, it also sounds like its stumbling a bit at low rpms. grab yourself a timing gun and go to work.

 

I was thinking that too, but I also though he might have some mixed up wires somewhere because he has no reverse lights, so his battery might be low because of a draw in the system.

 

thats possible, but it sounds like it is breaking up down low. that wouldnt be due to battery, i think the timing is off. set you initail timing around 9* and total 32-36* is about right then go from there. black plugs means its running rich so would stumbling at low rms... but if you timing is off you may be running just right its just not burning the fuel completely spewing it out through the exhaust. once the timing is set and your still having issues adjust the carb, i cant help you there i dont know carbs well

 

maybe 20hp

 

So far the only lights I have hooked up is headlights. Long story. I have a post about it in the electrical section. Battery is brand new as of Tuesday. The battery does seem drained though, the signal wire coming from the alt is barely hanging on so I don't think alternator is putting anything out at the moment. Before it started right up, starter never hanged.

 

By the way, today I unplugged the vacuum advance and plugged it, took it for a drive and it ran ten times smoother!!! Still stumbles a bit at light throttle but 3/4 to WOT is smooth sailing! Does that tell you anything about my timing? It was plugged into manifold vacuum and not ported vacuum.

 

yes your timing is to advanced. What is it set at?

 

This is a video with the vacuum advance unplugged. I think it runs better and doesn't sound as off anymore, what do you guys think? I'm thinking maybe retarding the timing a few degrees might solve my problem.

 

ok I will ask again. What is the timing at? Are you setting it by ear?

Also when I mentioned your timing is probably out you said "Timing is pretty much spot on".

 

By ear, my timing chain cover doesn't have a timing tab. I just got one, I just haven't had much time to put it on yet. This is how I did it..took the heads off, made sure cylinder was at tdc on compression stroke, put it all together, had the rotor pointing at the correct one. Fired her up and then turned the dist. Each way to find the sweet spot on the vacuum gauge with the vacuum advance disconnected and plugged. I advanced it just a tad after that. I stopped there because I wasn't able to take it out and put a load on it because it was on jackstands getting the exhaust done. I know I know get a timing light and a tab and actually check it and quit playing the guessing game. But I don't know where my timing is supposed to be at because there are a lot of factors going into the equation. Someone help me out here.

 

There is a reason myself and a few other people said to check your timing and this is it.
I you advanced the timing untill you got max vacuum at idle your timing is way to advanced. Depending on how big the cam is you could have 40 or 50 degrees at idle plus another 20 degrees of advance!
You must get the timing set correctly before you can do anything else. Do not drive the car until the timing is set correctly. With the timing that far advanced you can do damage to the pistons and bearings.
Put the timing tab on and double check tdc then set the timing to 16 at idle for now.
What kind of distributor do you have?

 

Alright, as soon as I get the time I will put the cover with the tab on, grab timing tape and hit it with the gun. Just for confirmation, what is the proper way to set the timing? I believe it's just the gm stock distributor that came with the Camaro original high output motor.

 

If it is the distributor that came with the computer controlled quadrajet you can not use it as it has no mechanical advance in it.
Take the cap and rotor off and post a pic of what is under the rotor and i can tell you if it is the correct distributor or not.
btw you can buy a timing tab that goes in 2 timing cover bolts for like $5 at autozone instead of changing the whole cover

 

Alright, it will have to be tomorrow or Tuesday before I can. Where does the timing tab go on the cover, I've heard of two different places. I think it has the 8" balancer on it if that makes a difference.

 

just buy one for an 8" balancer. It's self explanatory where it bolts to.

 

I did this today and it worked!

 

Idle mixture circuits were clogged, idle speed was too high causing fuel drip from the primaries, blew compressed air and carb cleaner through the idle circuits, and lowered the idle speed. Also number 6 spark plug wire was arcing to the headers. So stumble at idle and the feeling like it's not running on all 8 taken care of. Probably going to look into header wraps and wire protectors. Also going to get a new set of wires and some fuel filters.

 

1 hp per cubic inch is not easy to do. GM could never do it, that's for sure. We can do it if we sacrifice enough low end torque and put enough money into cylinder heads.

Basically your cheapest way to get into the 350-400 range is to hope you have flat top pistons that arent .045 in the hole, and then to get some Vortec heads and switch to an XR276 roller cam. That will require machining the valve guide to get enough clearance for that lift. That cam is 224/230 @ .050 and should have a power band around 2000-5800 or so. It should get you between 350-380hp. A cheaper option is Vortec heads and an LT4 hotcam, that's about 325-350hp, again, roller cam. You have an early 80's block, so you're not going to be able to go roller cheap... The only way to hit 350+ hp on a 350 is good heads and a good cam. Doing it and keeping the street manners is easy if you can go roller cam. If you're limited to flat tappets, you're gonna have a rough time of it. Maybe something like an xe274, but that's pretty lumpy for a street cam although you have the gearing for it. An xe268 is a reasonable street cam and will get you 310-340hp on a 350 with decent heads.

 

Thanks for that! I'll keep it in mind