well i must say i paid 80 bux for a slap in the face and to be kicked in the nuts. i dont know where to go from here. i am assuming it boils down to timing and a good tune on the carb. heres the run down i peaked at 158hp and 250 torque out of a 383 with a 750 edelbrock performer carb with a 1" spacer on a performer rpm intake. i am running what is said to be 350hp cam which is a .480/.480 lift with 1.5 rockers. i know there is more in there but im not sure how to find it. i believe it is running about 18* initial timng and reaches 36* at about 2500 rpm. i am also using a 6al ignition box. i was running at about 6-8* base timing before and it ran good but not sure what it would have dyno'd at that but when it was at that it would pop through the carb sometimes when you stomp on the gas. if anybody has any ideas i would appreciate it. thanx vinnie

 

That was a disappointing day at the dyno. A bad day would have been taking the engine, transmission, or rear end home in a basket.

To find it would mean knowing exactly what your timing is (or pulling to find the sweet spot), and getting A/F ratio on the dyno.

 

post a copy of your dyno sheet, it holds a good deal of info that will help isolate the problem

 

I notice you didn't mention anything about heads or exhaust in your post. If these are still stock, those numbers wouldn't be too suprising.

 

wat is the duration on the cam?? lsa??

 

Need more specific info on the heads, cam specs ( the "350hp" cam does not have .480" lift) pistons compression ratio exhaust etc etc.
if you have say stock smogger or TBI heads, low compression, crappy exhaust ( typical cheap shorty headers into a very small Y pipe and a crappy fuel pump and lines 158hp on the chassis dyno would be a good reading.
You say 36deg at 2500rpm. how much timing at 4000rpm. how much at 5000rpm. Should not exceed 36deg.

 

the duration on the cam is 230*
i have edelbrock tes headers with a complete 3" exhaust the whole way no emissions and ran open exhaust on dyno
aluminum heads 2.02-1.6 64cc and 200cc intake supposed to be around 10:1 or so with the pistons i have
i dont remember on the the fuel pump i think a summit 110gph mechanical pump and stock lines

on the dyno it seems everything goes down hill after 3200-3500 rpm hp peaks at 3500 and torque at 3200 rpm by the time i hit 5500 rpm im down to 85 hp. i hope this helps.
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also the lines get real sguiggly around 3800 rpm

 

230 degree advertise or at .050 lift? makes a difference... also if the car was hooked up wrong ( unlikely but may have been the prob) it would read all wrong and screw the rest of the readings up

 

yes at .50 lift and all they did was put a wire on number 1 spark wire and back tires on the roller is that all they do? i dont think the did anything else it was my first dyno. it was at a car show across the street from my house so i dont know what is normal for this proceedure.

 

We dyno'd cars back when i was in school UTI. That is the set up. the one thing to look for though is if any other wires are close to the pick up maybe there is interference..

like i said b4 it is unlikely tho. maybe there was a correction factor applied to the results.... would be nice to see a pic as asson as you can post one

 

you can view my dyno sheet here
http://www.cardomain.com/ride/2211363/1

it may be hard to see i have a piece of junk camera and no scanner and i can never post a pic here it always tells me file is too big.

but anyway top line is torque which peaked at 248 at 300rpm and the lower line is hp which peaked at 158 at 3600 rpm then it gets real squiggly and goes down hill.

 

they maybe put a fan blowing from the front end.. but anyway, that doesnt sound good at all.. the only thing left to look at is the carb.. also, check the valves for proper lift.. hopefully your cam hasnt ground down.. when my cam went flat, it fell on its face at about 3800

 

I'm assuming this was a chassis dyno? Car Craft actually had the exact same problem...they couldn't get the thing to make any power past 3500 RPM...it just died off right there.

One of the things they came up with was a bad torque converter (theirs was brand new...so don't let that fool you if you've replaced it). Another would be bad valvesprings (very bad valvesprings). I don't believe they ever reported what exactly it was.

 

i was thinking of taking to a place where they can test and tune on a dyno and go from there but that is exspensive though. the last time the carb was tuned i had 1.6 rockers then i went to 1.5 and havent changed the carb yet because im not too familiar with that. how much of a difference would the rocker change make???

 

I know I'd trash the edelbrock carb. That may be a good chunk of your problem. A good mechanical q-jet will perform better than any edelbrock. You should look into getting a DP Holley or BG or Demon or somethign like that. Stay away from edelbrock carbs.

 

Looks alot like what happens when the throttles don't open all the way.

Have somebody sit in the car and floor the gas pedal; and see if they do.

Hard to believe somebody would take your money at the dyno and not observe the car looking for simple stupid stuff like that.

It would REALLY REALLY REALLY help if you told us what cam it REALLY is, preferably by part number. ".480 lift" is pretty useless. If you yourself don't know any more than that about it, maybe you should consider selecting the exact right one for it, instead of guessing about it.

 

well the part number for the cam is melling #22301. i also found that i broke a push rod i dont know if that happened on the dyno or not i think it did though but i fixed that and still dont have a whole lot of power. im goin to change all my push rods to the chrome moly one piece rods then start playing with the timing again. is holley really that much better of a carb??? what makes them so much better???

 

edelbroke just ahs a poorly design carb. personally the accelerator pump push rod( red plastic pos) ended getting ground up and sticking all the time

 

Sucks to hear about your numbers man. But don't feel to bad, my brother has a friend with a 72' Nova with a 383" dart heads and a stall that only can run 9.2 on the eigth.

How do you think you runied a pushrod. I wonder if the valves weren't properly adjusted. This could cause a major power loss.

I don't want to start a fight about the edelbrock/holley thing. I'll just give my two cents over why i like holley's. Parts are easily available, and generally more affordable. I also think the holley is an easier carb to understand and repair. But if I wouldn't go as far to say that the edelbrock is junk, just something I wouldn't put on any of my cars.

 

well i adjusted all my valves with about 3/4 turn. after i change all the push rods i'll take a look at the movement of the rocker arms to see if any lobes are completly gone or not and if not i'll just have to take it and have a test and tune done. the other thing i changed before i went to the dyno beside putting on a 1" spacer and timing i also went from silver springs to copper springs which allows the full mechanical advance to come in faster so maybe that is the problem as well. any thoughts??? has anyone ever used a spacer on a performer rpm intake and have problems??

 

also if i cant find hp i should be getting what are some suggestions for carb size and anything else???