lack of power?

[Justins72]

ok my grandpa found the specs on the motor that was built for my car. But its lacking a lot of power. The engine specs are
Manifold: LD 340 edelbrock
Carb: demon 750 mech secondaries
Distributor: Accel electronic
Lifters: Isky anit pump up 3002
push rods: Norris adjustable
cam: Howar racing 310 dur 280 lift 465
timing: Cloyes True roller
cam barings: clevite
crankshaft:Balanced, forged, shot pinged
Psitons: speed pro, .030
Rods: balanced shot pinged
main barrings: clevite trw 77
rod barrings: trw clevite 77
oil pump: direct connection high volume
rings: racing cutome
Heads: 360 match port, polish
valves: speed pro 2.02 int 1.65 exh
retainers: norris titanium
I know its not much information but im hoping that the cam was degreed wrong. anything that looks like i should up to date since it was built a while ago? They tell me that it should be putting out around 450 hp, does that sound about right?  thanks

[HP2]

450 sounds pretty optimistic. I'd say probably more like 360-380.

It looks like a decent collection of parts. The biggest potential problems I see on that list would be 1) the heads, 2) pistons, 3) how tight they fit together, 4) whether the cam is appropriate for that amount of compression.

Compression makes power. Air flow makes power. If you don't have enough airflow into/out of the engine and then you don't squeeze it as much as your octane allows, then you are giving up power. What kind of work was done to the heads?

Can you check cylinder pressure and let us know what it comes in at?

[cudabob496]

whats your timing curve at?

[hemiken]

It would be compression problem or more a lck of it and the camshaft is only little considering, i would say this would be a bit more torquey than having anywhere near 450 hp, i would say more in the vercinaty of 350 hp with this camshaft, but does depend on compression.

[ViperMan]

Does anyone else think that 750cfm from the carb might be a smidge low?  My 318 has a 650cfm on it, without half of those upgraded parts.  I'm being told 950 for my 440-gone-512...  I'd think somewhere around 850 for this setup.

Then again I'm not (yet) the expert. 

Jeff

[HP2]

No, with that combo of parts, 750 is fine. Maybe with a a new Air Gap intake you could use 850, but, your still only gaining another 10-12 horses with it.

[MEK-Dangerfield]

No, with that combo of parts, 750 is fine.

   

[ViperMan]

Yeah reading some other posts I started to think that 750 was fine.

You gave us the specs on the motor and such - has it been run in a while?  What's the history on the engine?  Does it just need a good tune-up?

Jeff

[Chryco Psycho]

any Cam specs , what size is the engine ?

[bordin34]

Have you checked the timing?

[Justins72]

The engine is a 340 bored .030 over. It has been ran as i drove it for awhile, car seems to run and idle good but just seems to have no balls. The only specs i have on the cam is what i put down in the first post, howard racing 310 280 dur 465 lift. The car sat for awhile when it was my grandpas since he seemed to think there was a brake problem, car stops better then my 94 trans am. I have since replaced the coil with a msd blaster, Mopar chrome box, new plugs, and the timing is around 35 degrees.

[Bullitt-]

Assuming that the cam is degreed correctly the good idle and runs OK seem to indicate that I would look at 3 things....
1 You have good fresh fuel & is getting enough, no blockages in the filters.
2. Vacuum leaks, engines run OK with leaks but lack power, when you release the throttle does it take a long time to get back to idle?                        check this link http://www.aa1car.com/library/vacleak.htm
3. Where is your idle timing set & what is the maximum advance?  Without a timing light & degree tape on the harmonic balancer you probably can't tell but if your starting too retarded or the advance mechanisms, vacuum & mechanical, are not working you won't have much power. A good place to start is 8-10 degrees BTDC at idle.

[EVIL72]

 What gears do you have in the rear end? A set of freeway gears will turn an otherwise good motor into a slug.

[Justins72]

ok yes there was a leak that was between the carb and manifold which im sure i fixed. Also i read somewhere that disconnecting the vacuum advance would make the car run better, so i did and the outcome that it did idle better. The rear gears are definetly not freeway gears as im running at 3000-3500 at 60mph. Everyone is saying that i should have about 300 to 350 hp maybe im just not feeling it because i have 450hp stuck in my head since thats what everyone in my family that got the motor built is telling me. Also im used to driving a 94 trans am and im just not used to the heavy challenger. My uncle was telling me that cam could not be degreed right, was also telling me that the cam could not be a match to the rest and i should take the heads off, get them flow tested and then call comp cams a get a custom grind to what it flows.

[Chryco Psycho]

I agree that the cam could be the issue , if it has 310 duration & .465 lift it is not a great grind , I would be looking at replacing it with an Engle K56 approx , Far better cam choice , have you done a compression test just to get a ball park on the compression ?