340 not pulling the way it should

[leanburn]

i finally got my cuda to the track and i'm not impressed. i have a dart with half the motor that runs 2 tenths faster. i made 2 passes at 13.8's each and started tuning. i went up a couple of jet sizes and there was no difference [ plugs were a better color]. i then put a timing light on it and i was getting readings all over the place, 24*, 20* and a base of 0*. i realized i was out of my league so i got a couple of buddies who have been around for awhile. we popped the distributor cap off and found the weights to be totally seized. we cleaned them up and got them working and replaced the springs wich were the stiffist to some that would advance around 2500. i had my hopes up bigtime thinkin we solved the problem and 13.8 again. we installed some softer spring again [ 2200 ish] and again 13.8.
 i'm having a hard time believeing that we found something that major and it didn't change at all. everybody that was helping could not understand how this thing was even running when we first took it apart.
 is there something were overlooking, does anyone have any ideas why timing would not effect performance ?
 i also can't get the engine specs off the jerk who sold me this car so i can't give you cam specs but this is what the engine is supposed to have:
10:1, ported x heads, msd 6, msd distibutor no vacuum, 750 demon, roller rockers, tried 34* and 36*.
 i noticed that the throttle response isn't terrible but not great and my 60' times are consistently 2.14 to 2.16 [should be 2.0 easy].

[GoodysGotaCuda]

How about the tune on that demon? What is the rest of the drivetrain like? I doubt you've had it apart to check cam timing, but that is another possibility. 13.8? Thats 318 territory 

[leanburn]

o.k, after getting totally ignorant with the guy he finally give me some info on the cam. alot of the info he sent me is over my head so i wrote down some basics.
  custom ground
 intake: 500 lift, opens 5.0 btdc, closes 43.0 abdc, 228*
 exh: 520 lift, opens 58.0 bbdc, closes 0.0 btdc, 238*

is there any info i'm missing? is this cam anygood or should i look at changing it out.

[GoodysGotaCuda]

i'm not the best at computing cam timing in my head but that sounds about fine to me. When i mentioned cam timing i was meaning if the previous owner had properly degreed the cam in or not. That could throw your engine out of whack pretty well, and i do believe that a symptom of ignition timing not helping. (someone double check/correct on that one?)

[leanburn]

this has come up in conversation with a couple of buddies. what would be required to find out, how deep would i have to dig?

[nivvy]

Spuradic readings can b from your spirngs...also darts are light cars to e.t. faster but are you making and asumption that the heavier springs are coming in at 2500 total advance... I know them garage door springs on my msd with the smaller busing come in around 4500rpm range...

when you mean a base of 0* are you talking initial and 24* total...

[GoodysGotaCuda]

front of the engine would need to come off and the drivers valve cover. basically get to the timing chain. You would need a dial indicator, degree wheel, and someone that has definately done it a few times to help (it can be done reading the instructions, however for me its hard to learn that way). I'm not recommending just jumping in and tearing the thing apart like that, but it is a possibility. That'd be the last attempt, have you done a compression test?

To be removed:
Drivers valve cover
p/s pump moved
alternator
water pump
crank pulley
harmonic balancer
timing chain cover
radiator
fan

[nivvy]

use the light blue and light silver spring and the black bushing... rev up to 3000 grand and set timing at 36* and you should have 18* mechanical advance and 18* initial.... wit the spirng/bushing combo i suggested...

[nivvy]

intake: 500 lift, opens 5.0 btdc, closes 43.0 abdc, 228*
 exh: 520 lift, opens 58.0 bbdc, closes 0.0 btdc, 238*
 

5.0 btdc

closes 0.00 btdc 

[leanburn]

the light blue and silver was tried, then we went a little lighter [ can't remember colors] with total advance of 38* and as i said there was absolutely no change whatsoever from when my weights were seized and only giving me a max of 24*.
 those cam #'s have me baffled to, i figured you guys could make heads or tails of them. he did give me more info but it's all the same garble.
 
another thing i tried today was advancing as far as i could to see if i could get some pinging. i don't have a light at home but i know i was at 38* before i started and i advanced it as far as i could without it dying at an idle and the only time i get any rattle is a tiny bit at about 2000rpm. what kind of total timing should i hear pinging at top end.

[leanburn]

oh yeah and compression is all 160 to 165 on all cylinders.
 

[nivvy]

the light blue and silver was tried, then we went a little lighter [ can't remember colors] with total advance of 38* and as i said there was absolutely no change whatsoever from when my weights were seized and only giving me a max of 24*.
 

the only thing lighter than the blue/silver combo is silver/silver.... what color bushing is under there???

[Oldschool]

Leanburn stated that his 60' times were 2.14-2.16.  He also says they should be 2.00 easy.  I don't think that timing advance is going to pick up a tenth and a half in the 60' times.  Sounds more like torque converter or rear gear or traction issues to me.  I am not saying that getting the timing right won't help, but to get the kind of 60' times improvement he is looking for, he needs to look at the things that effect the launch. In a street car, improvements in the converter, rear gear, and traction will definitely help cut down those 60'  times...               

[nivvy]

somthing aint right... with the stiffest springs he aint gonna have his advance come in at 2500rpm even with the biggest bushing 

did yu have it timed in the 1/4 before... kindasounds like yo just bought the car off a guy... and was expecting more/// did you pull the valve covers to see if you had roller rockers....  hows your lash settings...

[leanburn]

i had the stiffest springs in and we changed them to lighter ones. yes i definately have roller rockers but have not checked my lash yet.
 i know exactly what you mean as far as expecting to much from the car, i did not build this engine, i'm taking the guys word but when you add 14* total timing and there is no change i would have to say there is s :pullinghair:omething wrong.