I made a post a couple of days ago i dont know if someone dont like me or an error occured but I have got a problem of no-power and no more RPMS than 4... I have a 408 BB in a camaro with KB pistons, comp cam(270H), valve job done along with the boring and new cam (no more than a week)Have headers and some intake that was on it... a edelbrock of some kind, and a 600 4b edelbrock carb... does anyone know what could be causing this low power low RPM condition?

Cig, I went and read your previous post but your description of what is happening is not very clear. What does the motor sound like when it hits its rpm limit? Does it pop? Bog down? Surge? Does it do this all the time or just under certain conditions? For example, does it do this with the air cleaner on but is ok with it off?

It seems like you are running out of something. Not enough air through carb. Not enough spark--timing out? Fuel starved? Exhaust has an obstruction? Possibly a vaccum leak in the intake manifold since you just installed it. Try spraying around the intake to head gasket with WD40 or something like that. As you work around the gasket and you find that the engine suddenly runs better you have just found a vac. leak.

Post a more detailed description and someone around here should be able to help you come up with a solution. smile.gif

If you converted to HEI be sure you have 12 volts going to it! Or carb linkage not opening fully opening or distributor not advancing!! :confused:

Carb secondaries not opening,
What carb????

When the engine reaches that limit it sounds merely like an engine striking a low limit you can tell it has more to go it just will not reach it. It runs very smooth and does not pop or backfire even.
The carb is a 600 edelbrock manual choke. I checked the fuel pressure b4 dissasembly and it was fine but I havent checked that yet. I will have to take it to the shop and run it.
I have yet to change the spark plugs which is my next endevour.(like maybe tomorow)
The engine is in time.
I dont know about any vacuum leaks. I should just spray around the intake right?
I think maybe when I get enough money i am gonna buy a 750 edelebrock spreadbore prehaps that would get enough gas into it to burn it.

o yeah and i have a full 12 volts on the ignition i forgot about that

Are you using an msd box or something like it? Could the rev limiter be set at the point it poops out?

Are the valve springs what the comp cams recommends? Exhaust restriction?

My kid's new (used) car did something like that, no power and hard to get rpms. The engine was built by a machine shop with all the right parts. After some searching we checked the cam/crank timing. It was way off. We matched it back up and now it runs very strong. Just a thought Rhat

well I am using no MSD box so there can be any limiter... the valve springs are so far as I KNOW factory... there should be no exhaust resistance it has tuned headers with straights till some glass packs which i hate... and as far as the cam/crank timing if ur refering to lining up those marks to get them in co-ordination we set that when installing so im not sure thats it... I have come to decide that is more than likely the carbarator, after driving it i noticed when i stomp it, It hesetates then begins pulling but no where near to what it should i think maybe the carb is the problem, i hope to put an EFI on this puppy but thats a 2k project so it could be postponed for some time

two things, that 600cfm carb is way too small! at least a 650dp. second it could be the cam timing, on some of the adjustable comp cams timing sets, it is confusing, they have two 0's. the dot should be pointing straight up and the keyway(ruffridge key) should be pointing off to the right at about 2 o clock, sometimes you don't use the "0" you have to use the square or something like that.

I would think that it is more likely to be the timing than the carb. Even a carb that is too small will allow the engine to rev up under normal conditions. I would triple check the timing, start with the easy thing and make sure the distributor is not off by a tooth. Make sure you have a good manifold vac source(bottom plate on carb or manifold itself) for your vac advance. Then if that does not work pull the timing chain cover back off and TRIPLE check that everything is lined up correctly. You may be right about the carb but my money is on the timing issue.

Oh yeah, one more thing. Bad timing can cause the engine to hesitate and accelerate poorly as well.

well looks like im off to check the timing, ill messege u guys back whenever i find something